jcode + GPT-5.4 on float-print

{"goals": [{"end_to_end_ownership": null, "feedback_loop": "Run ./grade after each meaningful optimization and compare score plus correctness.", "group": "float-print optimization", "hill_climbability": 95, "objective": "Maximize deterministic callgrind speedup while preserving exact output on all verifier inputs.", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100}], "intent": "Track benchmark optimization plan", "todos": [{"completion_confidence": null, "confidence": 95, "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "group": "float-print optimization", "id": "read-spec-code", "priority": "high", "status": "in_progress"}, {"completion_confidence": null, "confidence": 85, "content": "Profile and optimize submission implementation with repeated grade runs", "group": "float-print optimization", "id": "optimize-grade", "priority": "high", "status": "pending"}, {"completion_confidence": null, "confidence": 80, "content": "Validate final implementation, record best score, and summarize changes", "group": "float-print optimization", "id": "finalize-report", "priority": "medium", "status": "pending"}]}

[ { "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "status": "in_progress", "priority": "high", "id": "read-spec-code", "group": "float-print optimization", "confidence": 95, "confidence_history": [ 95 ] }, { "content": "Profile and optimize submission implementation with repeated grade runs", "status": "pending", "priority": "high", "id": "optimize-grade", "group": "float-print optimization", "confidence": 85, "confidence_history": [ 85 ] }, { "content": "Validate final implementation, record best score, and summarize changes", "status": "pending", "priority": "medium", "id": "finalize-report", "group": "float-print optimization", "confidence": 80, "confidence_history": [ 80 ] } ] Goals: [ { "group": "float-print optimization", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100, "hill_climbability": 95, "objective": "Maximize deterministic callgrind speedup while preserving exact output on all verifier inputs.", "feedback_loop": "Run ./grade after each meaningful optimization and compare score plus correctness." } ] Your hill-climbability is not high enough. First, improve the goal's objective and feedback loop so progress can be measured across iterations. Then call the todo tool again with the revised goal before continuing the task. The goal is to create a strong feedback loop you can iterate against.

{"goals": [{"end_to_end_ownership": null, "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline.", "group": "float-print optimization", "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session.", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100}], "intent": "Strengthen measurable optimization loop", "todos": [{"completion_confidence": null, "confidence": 95, "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "group": "float-print optimization", "id": "read-spec-code", "priority": "high", "status": "in_progress"}, {"completion_confidence": null, "confidence": 85, "content": "Profile and optimize submission implementation with repeated grade runs", "group": "float-print optimization", "id": "optimize-grade", "priority": "high", "status": "pending"}, {"completion_confidence": null, "confidence": 80, "content": "Validate final implementation, record best score, and summarize changes", "group": "float-print optimization", "id": "finalize-report", "priority": "medium", "status": "pending"}]}

[ { "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "status": "in_progress", "priority": "high", "id": "read-spec-code", "group": "float-print optimization", "confidence": 95, "confidence_history": [ 95 ] }, { "content": "Profile and optimize submission implementation with repeated grade runs", "status": "pending", "priority": "high", "id": "optimize-grade", "group": "float-print optimization", "confidence": 85, "confidence_history": [ 85 ] }, { "content": "Validate final implementation, record best score, and summarize changes", "status": "pending", "priority": "medium", "id": "finalize-report", "group": "float-print optimization", "confidence": 80, "confidence_history": [ 80 ] } ] Goals: [ { "group": "float-print optimization", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100, "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session.", "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline." } ] Goal updates: [ { "before": { "group": "float-print optimization", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100, "hill_climbability": 95, "objective": "Maximize deterministic callgrind speedup while preserving exact output on all verifier inputs.", "feedback_loop": "Run ./grade after each meaningful optimization and compare score plus correctness." }, "after": { "group": "float-print optimization", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100, "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session.", "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline." }, "fields": [ "hill_climbability", "objective", "feedback_loop" ] } ]

{"intent": "Inspect benchmark spec and submission code", "tool_calls": [{"tool": "ls", "path": ".", "ignore": [".git", "node_modules", "target"], "intent": "List repository files"}, {"tool": "read", "file_path": "spec.md", "start_line": 1, "limit": 400, "intent": "Read benchmark specification"}, {"tool": "read", "file_path": "submission/solve.c", "start_line": 1, "limit": 400, "intent": "Read current submission implementation"}]}

--- [1] ls --- ./ submission/ solve.c verify/ gen_corpus.py given.c runner.c verify.c grade scores.jsonl spec.md 8 files, 2 directories --- [2] read --- 1 # float-print 2 3 Print a float32 as the shortest decimal string that parses back to the same bits. 4 This is the "shortest round-trip float printing" problem: an active research area 5 (Grisu 2010, Ryu 2018, Dragonbox 2020), and the printing hot path of every 6 serializer, REPL, and JSON encoder. 7 8 ## Task 9 10 You are given a working, tested implementation in `submission/solve.c`. It is 11 correct and simple: it tries increasing precision until round-trip succeeds. 12 Make it faster. Correctness on every one of the 2^32 float bit patterns is the 13 gate. 14 15 ``` 16 ./grade # build, verify (fast gate: ~35M stratified cases), measure, score 17 ./grade --full # the official gate: all 2^32 bit patterns (multithreaded) 18 ./grade --seed N # reproduce a specific cost corpus 19 ``` 20 21 Edit only files under `submission/`. 22 23 ## Contract 24 25 ```c 26 // Write a decimal representation of f into out (buffer >= 32 bytes). 27 // Returns the number of bytes written (no NUL required). 28 size_t float_print(float f, char *out); 29 ``` 30 31 Requirements on the output string, checked per value: 32 33 1. **Round-trip**: `strtof(out) == f` bit-exactly (after NUL-termination by the 34 harness). For -0.0f the output must parse to -0.0f (sign preserved). 35 2. **Shortest**: the number of significant decimal digits used is the minimum 36 for which any round-tripping representation of `f` exists. 37 3. **Format**: `-?D(.D+)?(e[+-]?DD?)?` where D are digits, i.e. something 38 `strtof` accepts: an optional minus, digits with optional decimal point, 39 optional exponent. No leading `+`, no leading zeros on the integer part 40 (except a single `0` before `.`), no trailing zeros in the fraction. 41 `inf`, `-inf`, `nan` (exactly these, lowercase) for infinities and NaNs. 42 4. Length <= 31 bytes. 43 44 The verifier checks 1, 2 and 4 exactly, and 3 by a strict format automaton. 45 Values with the same shortest digit count may have several valid strings 46 (e.g. exponent vs plain notation); any compliant one passes. 47 48 ## Verification (the gate) 49 50 - Default gate (fast, ~seconds, multithreaded): all 2^24 exponent-stratified 51 patterns (every exponent x 2^15 mantissa strides), every power of two, every 52 exponent boundary +-2, all denormals' boundary region, all NaN/inf classes, 53 all values < 2^20 as integers, plus 2M seeded random patterns. 54 - `--full`: every one of the 2^32 bit patterns. This is the official gate and 55 runs in a few minutes on 8 threads. Run it before you claim a final score. 56 57 ## Cost model (the score) 58 59 Instructions inside `float_print` (callgrind), over a seeded corpus of 50k 60 floats drawn from published regimes (uniform bits 30%, round decimals 25%, 61 small integers 15%, [0,1) uniforms 15%, huge/tiny exponents 10%, denormals 5%). 62 Paired: the frozen given implementation (`verify/given.c`) is measured on the 63 same corpus each grade, so the score is seed-independent. 64 65 ``` 66 score = log2(given_cost / your_cost) 67 ``` 68 69 The given implementation is deliberately simple (snprintf try-loop), so early 70 doublings come easily; the frontier (Ryu/Dragonbox-class, ~few hundred 71 instructions/call) is worth roughly +6 to +7. Beyond the frontier is research. 72 73 ## Rules 74 75 - Self-contained C17, libc only. You may (and should) replace the snprintf 76 approach entirely. 77 - Do not modify the grader/verifier. Any correct program is a valid submission. --- [3] read --- 1 // solve.c — the given implementation of float_print. 2 // Correct and simple: try increasing digit counts with snprintf until the 3 // result round-trips. This is what a careful programmer writes first, and 4 // it is slow. Make it faster. See ../spec.md. Grade with ../grade. 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <string.h> 8 #include <math.h> 9 #include <stdint.h> 10 11 size_t float_print(float f, char *out) { 12 // Specials. 13 if (isnan(f)) { memcpy(out, "nan", 3); return 3; } 14 if (isinf(f)) { 15 if (f < 0) { memcpy(out, "-inf", 4); return 4; } 16 memcpy(out, "inf", 3); 17 return 3; 18 } 19 if (f == 0.0f) { 20 // preserve sign of zero 21 if (signbit(f)) { memcpy(out, "-0", 2); return 2; } 22 out[0] = '0'; 23 return 1; 24 } 25 26 // Try shortest first: %.<p>g produces p significant digits. 27 char buf[64]; 28 for (int prec = 1; prec <= 9; prec++) { 29 int n = snprintf(buf, sizeof(buf), "%.*g", prec, (double)f); 30 if (n <= 0) continue; 31 float back = strtof(buf, NULL); 32 if (back == f) { 33 // normalize: %g may emit exponents like e+05; strip leading 34 // zeros in the exponent to keep the format tight (e+05 -> e+5). 35 char *e = memchr(buf, 'e', (size_t)n); 36 if (e) { 37 char *p = e + 1; 38 char sign = 0; 39 if (*p == '+' || *p == '-') { sign = *p; p++; } 40 while (*p == '0' && p[1] != '\0') { 41 memmove(p, p + 1, (size_t)(n - (p - buf))); 42 n--; 43 } 44 if (sign == '+') { 45 // keep '+'? strtof accepts both; keep as-is (allowed). 46 } 47 } 48 memcpy(out, buf, (size_t)n); 49 return (size_t)n; 50 } 51 } 52 // 9 significant digits always round-trips for float32. 53 int n = snprintf(buf, sizeof(buf), "%.9g", (double)f); 54 memcpy(out, buf, (size_t)n); 55 return (size_t)n; 56 } Completed: 3 succeeded, 0 failed

{"command": "./grade", "intent": "Run baseline grade for current implementation", "notify": false, "run_in_background": false, "timeout": 1200000, "wake": false}

build 0.6s verify 13.6s PASS measure 18.0s 4,493,047,279 instructions (given: 4,493,047,279) SCORE +0.0000 (1.000x) --- Command finished with exit code: 0 ---

{"intent": "Fetch Ryu float implementation references", "tool_calls": [{"tool": "websearch", "query": "Ryu f2s.c GitHub float to string shortest roundtrip C", "engine": "duckduckgo", "num_results": 5, "intent": "Find public Ryu float-only C implementation"}, {"tool": "websearch", "query": "ryu d2s.c f2s.c LICENSE GitHub", "engine": "duckduckgo", "num_results": 5, "intent": "Find official Ryu repository"}, {"tool": "read", "file_path": "verify/given.c", "start_line": 1, "limit": 220, "intent": "Check given implementation and build setup"}]}

--- [1] websearch --- Error: DuckDuckGo served an anti-bot challenge page (anomaly challenge) instead of results. This is commonly caused by TLS fingerprinting or IP reputation on Linux. Falling back to another engine if configured. --- [2] websearch --- Error: DuckDuckGo served an anti-bot challenge page (anomaly challenge) instead of results. This is commonly caused by TLS fingerprinting or IP reputation on Linux. Falling back to another engine if configured. --- [3] read --- 1 // solve.c — the given implementation of float_print. 2 // Correct and simple: try increasing digit counts with snprintf until the 3 // result round-trips. This is what a careful programmer writes first, and 4 // it is slow. Make it faster. See ../spec.md. Grade with ../grade. 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <string.h> 8 #include <math.h> 9 #include <stdint.h> 10 11 size_t given_float_print(float f, char *out) { 12 // Specials. 13 if (isnan(f)) { memcpy(out, "nan", 3); return 3; } 14 if (isinf(f)) { 15 if (f < 0) { memcpy(out, "-inf", 4); return 4; } 16 memcpy(out, "inf", 3); 17 return 3; 18 } 19 if (f == 0.0f) { 20 // preserve sign of zero 21 if (signbit(f)) { memcpy(out, "-0", 2); return 2; } 22 out[0] = '0'; 23 return 1; 24 } 25 26 // Try shortest first: %.<p>g produces p significant digits. 27 char buf[64]; 28 for (int prec = 1; prec <= 9; prec++) { 29 int n = snprintf(buf, sizeof(buf), "%.*g", prec, (double)f); 30 if (n <= 0) continue; 31 float back = strtof(buf, NULL); 32 if (back == f) { 33 // normalize: %g may emit exponents like e+05; strip leading 34 // zeros in the exponent to keep the format tight (e+05 -> e+5). 35 char *e = memchr(buf, 'e', (size_t)n); 36 if (e) { 37 char *p = e + 1; 38 char sign = 0; 39 if (*p == '+' || *p == '-') { sign = *p; p++; } 40 while (*p == '0' && p[1] != '\0') { 41 memmove(p, p + 1, (size_t)(n - (p - buf))); 42 n--; 43 } 44 if (sign == '+') { 45 // keep '+'? strtof accepts both; keep as-is (allowed). 46 } 47 } 48 memcpy(out, buf, (size_t)n); 49 return (size_t)n; 50 } 51 } 52 // 9 significant digits always round-trips for float32. 53 int n = snprintf(buf, sizeof(buf), "%.9g", (double)f); 54 memcpy(out, buf, (size_t)n); 55 return (size_t)n; 56 } Completed: 1 succeeded, 2 failed

{"intent": "Fetch official Ryu source files directly", "tool_calls": [{"tool": "webfetch", "url": "https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/f2s.c", "format": "text", "timeout": 30, "intent": "Fetch Ryu float conversion source"}, {"tool": "webfetch", "url": "https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/f2s_full_table.h", "format": "text", "timeout": 30, "intent": "Fetch Ryu float power table header"}, {"tool": "webfetch", "url": "https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/common.h", "format": "text", "timeout": 30, "intent": "Fetch Ryu common helpers header"}, {"tool": "webfetch", "url": "https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/f2s_intrinsics.h", "format": "text", "timeout": 30, "intent": "Fetch Ryu float intrinsics header"}, {"tool": "webfetch", "url": "https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/digit_table.h", "format": "text", "timeout": 30, "intent": "Fetch Ryu digit table header"}]}

--- [1] webfetch --- Fetched https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/f2s.c (7018 bytes) // Copyright 2018 Ulf Adams // // The contents of this file may be used under the terms of the Apache License, // Version 2.0. // // (See accompanying file LICENSE-Apache or copy at // http://www.apache.org/licenses/LICENSE-2.0) // // Alternatively, the contents of this file may be used under the terms of // the Boost Software License, Version 1.0. // (See accompanying file LICENSE-Boost or copy at // https://www.boost.org/LICENSE_1_0.txt) // // Unless required by applicable law or agreed to in writing, this software // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY // KIND, either express or implied. // Runtime compiler options: // -DRYU_DEBUG Generate verbose debugging output to stdout. #include "ryu/ryu.h" #include #include #include #include #include #include #ifdef RYU_DEBUG #include #endif #include "ryu/common.h" #include "ryu/f2s_intrinsics.h" #include "ryu/digit_table.h" #define FLOAT_MANTISSA_BITS 23 #define FLOAT_EXPONENT_BITS 8 #define FLOAT_BIAS 127 // A floating decimal representing m * 10^e. typedef struct floating_decimal_32 { uint32_t mantissa; // Decimal exponent's range is -45 to 38 // inclusive, and can fit in a short if needed. int32_t exponent; } floating_decimal_32; static inline floating_decimal_32 f2d(const uint32_t ieeeMantissa, const uint32_t ieeeExponent) { int32_t e2; uint32_t m2; if (ieeeExponent == 0) { // We subtract 2 so that the bounds computation has 2 additional bits. e2 = 1 - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; m2 = ieeeMantissa; } else { e2 = (int32_t) ieeeExponent - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; m2 = (1u %u * 2^%d\n", m2, e2 + 2); #endif // Step 2: Determine the interval of valid decimal representations. const uint32_t mv = 4 * m2; const uint32_t mp = 4 * m2 + 2; // Implicit bool -> int conversion. True is 1, false is 0. const uint32_t mmShift = ieeeMantissa != 0 || ieeeExponent = 0) { const uint32_t q = log10Pow2(e2); e10 = (int32_t) q; const int32_t k = FLOAT_POW5_INV_BITCOUNT + pow5bits((int32_t) q) - 1; const int32_t i = -e2 + (int32_t) q + k; vr = mulPow5InvDivPow2(mv, q, i); vp = mulPow5InvDivPow2(mp, q, i); vm = mulPow5InvDivPow2(mm, q, i); #ifdef RYU_DEBUG printf("%u * 2^%d / 10^%u\n", mv, e2, q); printf("V+=%u\nV =%u\nV-=%u\n", vp, vr, vm); #endif if (q != 0 && (vp - 1) / 10 vm / 10) { #ifdef __clang__ // https://bugs.llvm.org/show_bug.cgi?id=23106 // The compiler does not realize that vm % 10 can be computed from vm / 10 // as vm - (vm / 10) * 10. vmIsTrailingZeros &= vm - (vm / 10) * 10 == 0; #else vmIsTrailingZeros &= vm % 10 == 0; #endif vrIsTrailingZeros &= lastRemovedDigit == 0; lastRemovedDigit = (uint8_t) (vr % 10); vr /= 10; vp /= 10; vm /= 10; ++removed; } #ifdef RYU_DEBUG printf("V+=%u\nV =%u\nV-=%u\n", vp, vr, vm); printf("d-10=%s\n", vmIsTrailingZeros ? "true" : "false"); #endif if (vmIsTrailingZeros) { while (vm % 10 == 0) { vrIsTrailingZeros &= lastRemovedDigit == 0; lastRemovedDigit = (uint8_t) (vr % 10); vr /= 10; vp /= 10; vm /= 10; ++removed; } } #ifdef RYU_DEBUG printf("%u %d\n", vr, lastRemovedDigit); printf("vr is trailing zeros=%s\n", vrIsTrailingZeros ? "true" : "false"); #endif if (vrIsTrailingZeros && lastRemovedDigit == 5 && vr % 2 == 0) { // Round even if the exact number is .....50..0. lastRemovedDigit = 4; } // We need to take vr + 1 if vr is outside bounds or we need to round up. output = vr + ((vr == vm && (!acceptBounds || !vmIsTrailingZeros)) || lastRemovedDigit >= 5); } else { // Specialized for the common case (~96.0%). Percentages below are relative to this. // Loop iterations below (approximately): // 0: 13.6%, 1: 70.7%, 2: 14.1%, 3: 1.39%, 4: 0.14%, 5+: 0.01% while (vp / 10 > vm / 10) { lastRemovedDigit = (uint8_t) (vr % 10); vr /= 10; vp /= 10; vm /= 10; ++removed; } #ifdef RYU_DEBUG printf("%u %d\n", vr, lastRemovedDigit); printf("vr is trailing zeros=%s\n", vrIsTrailingZeros ? "true" : "false"); #endif // We need to take vr + 1 if vr is outside bounds or we need to round up. output = vr + (vr == vm || lastRemovedDigit >= 5); } const int32_t exp = e10 + removed; #ifdef RYU_DEBUG printf("V+=%u\nV =%u\nV-=%u\n", vp, vr, vm); printf("O=%u\n", output); printf("EXP=%d\n", exp); #endif floating_decimal_32 fd; fd.exponent = exp; fd.mantissa = output; return fd; } static inline int to_chars(const floating_decimal_32 v, const bool sign, char* const result) { // Step 5: Print the decimal representation. int index = 0; if (sign) { result[index++] = '-'; } uint32_t output = v.mantissa; const uint32_t olength = decimalLength9(output); #ifdef RYU_DEBUG printf("DIGITS=%u\n", v.mantissa); printf("OLEN=%u\n", olength); printf("EXP=%u\n", v.exponent + olength); #endif // Print the decimal digits. // The following code is equivalent to: // for (uint32_t i = 0; i = 10000) { #ifdef __clang__ // https://bugs.llvm.org/show_bug.cgi?id=38217 const uint32_t c = output - 10000 * (output / 10000); #else const uint32_t c = output % 10000; #endif output /= 10000; const uint32_t c0 = (c % 100) = 100) { const uint32_t c = (output % 100) = 10) { const uint32_t c = output 1) { result[index + 1] = '.'; index += olength + 1; } else { ++index; } // Print the exponent. result[index++] = 'E'; int32_t exp = v.exponent + (int32_t) olength - 1; if (exp = 10) { memcpy(result + index, DIGIT_TABLE + 2 * exp, 2); index += 2; } else { result[index++] = (char) ('0' + exp); } return index; } int f2s_buffered_n(float f, char* result) { // Step 1: Decode the floating-point number, and unify normalized and subnormal cases. const uint32_t bits = float_to_bits(f); #ifdef RYU_DEBUG printf("IN="); for (int32_t bit = 31; bit >= 0; --bit) { printf("%u", (bits >> bit) & 1); } printf("\n"); #endif // Decode bits into sign, mantissa, and exponent. const bool ieeeSign = ((bits >> (FLOAT_MANTISSA_BITS + FLOAT_EXPONENT_BITS)) & 1) != 0; const uint32_t ieeeMantissa = bits & ((1u > FLOAT_MANTISSA_BITS) & ((1u << FLOAT_EXPONENT_BITS) - 1); // Case distinction; exit early for the easy cases. if (ieeeExponent == ((1u << FLOAT_EXPONENT_BITS) - 1u) || (ieeeExponent == 0 && ieeeMantissa == 0)) { return copy_special_str(result, ieeeSign, ieeeExponent, ieeeMantissa); } const floating_decimal_32 v = f2d(ieeeMantissa, ieeeExponent); return to_chars(v, ieeeSign, result); } void f2s_buffered(float f, char* result) { const int index = f2s_buffered_n(f, result); // Terminate the string. result[index] = '\0'; } char* f2s(float f) { char* const result = (char*) malloc(16); f2s_buffered(f, result); return result; } --- [2] webfetch --- Fetched https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/f2s_full_table.h (3240 bytes) // Copyright 2018 Ulf Adams // // The contents of this file may be used under the terms of the Apache License, // Version 2.0. // // (See accompanying file LICENSE-Apache or copy at // http://www.apache.org/licenses/LICENSE-2.0) // // Alternatively, the contents of this file may be used under the terms of // the Boost Software License, Version 1.0. // (See accompanying file LICENSE-Boost or copy at // https://www.boost.org/LICENSE_1_0.txt) // // Unless required by applicable law or agreed to in writing, this software // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY // KIND, either express or implied. #ifndef RYU_F2S_FULL_TABLE_H #define RYU_F2S_FULL_TABLE_H // This table is generated by PrintFloatLookupTable. #define FLOAT_POW5_INV_BITCOUNT 59 #define FLOAT_POW5_BITCOUNT 61 static uint64_t FLOAT_POW5_INV_SPLIT[55] = { 576460752303423489u, 461168601842738791u, 368934881474191033u, 295147905179352826u, 472236648286964522u, 377789318629571618u, 302231454903657294u, 483570327845851670u, 386856262276681336u, 309485009821345069u, 495176015714152110u, 396140812571321688u, 316912650057057351u, 507060240091291761u, 405648192073033409u, 324518553658426727u, 519229685853482763u, 415383748682786211u, 332306998946228969u, 531691198313966350u, 425352958651173080u, 340282366920938464u, 544451787073501542u, 435561429658801234u, 348449143727040987u, 557518629963265579u, 446014903970612463u, 356811923176489971u, 570899077082383953u, 456719261665907162u, 365375409332725730u, 292300327466180584u, 467680523945888934u, 374144419156711148u, 299315535325368918u, 478904856520590269u, 383123885216472215u, 306499108173177772u, 490398573077084435u, 392318858461667548u, 313855086769334039u, 502168138830934462u, 401734511064747569u, 321387608851798056u, 514220174162876889u, 411376139330301511u, 329100911464241209u, 526561458342785934u, 421249166674228747u, 336999333339382998u, 539198933343012796u, 431359146674410237u, 345087317339528190u, 552139707743245103u, 441711766194596083u }; static const uint64_t FLOAT_POW5_SPLIT[47] = { 1152921504606846976u, 1441151880758558720u, 1801439850948198400u, 2251799813685248000u, 1407374883553280000u, 1759218604441600000u, 2199023255552000000u, 1374389534720000000u, 1717986918400000000u, 2147483648000000000u, 1342177280000000000u, 1677721600000000000u, 2097152000000000000u, 1310720000000000000u, 1638400000000000000u, 2048000000000000000u, 1280000000000000000u, 1600000000000000000u, 2000000000000000000u, 1250000000000000000u, 1562500000000000000u, 1953125000000000000u, 1220703125000000000u, 1525878906250000000u, 1907348632812500000u, 1192092895507812500u, 1490116119384765625u, 1862645149230957031u, 1164153218269348144u, 1455191522836685180u, 1818989403545856475u, 2273736754432320594u, 1421085471520200371u, 1776356839400250464u, 2220446049250313080u, 1387778780781445675u, 1734723475976807094u, 2168404344971008868u, 1355252715606880542u, 1694065894508600678u, 2117582368135750847u, 1323488980084844279u, 1654361225106055349u, 2067951531382569187u, 1292469707114105741u, 1615587133892632177u, 2019483917365790221u }; #endif // RYU_F2S_FULL_TABLE_H --- [3] webfetch --- Fetched https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/common.h (2334 bytes) // Copyright 2018 Ulf Adams // // The contents of this file may be used under the terms of the Apache License, // Version 2.0. // // (See accompanying file LICENSE-Apache or copy at // http://www.apache.org/licenses/LICENSE-2.0) // // Alternatively, the contents of this file may be used under the terms of // the Boost Software License, Version 1.0. // (See accompanying file LICENSE-Boost or copy at // https://www.boost.org/LICENSE_1_0.txt) // // Unless required by applicable law or agreed to in writing, this software // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY // KIND, either express or implied. #ifndef RYU_COMMON_H #define RYU_COMMON_H #include #include #include #if defined(_M_IX86) || defined(_M_ARM) #define RYU_32_BIT_PLATFORM #endif // Returns the number of decimal digits in v, which must not contain more than 9 digits. static inline uint32_t decimalLength9(const uint32_t v) { // Function precondition: v is not a 10-digit number. // (f2s: 9 digits are sufficient for round-tripping.) // (d2fixed: We print 9-digit blocks.) assert(v = 100000000) { return 9; } if (v >= 10000000) { return 8; } if (v >= 1000000) { return 7; } if (v >= 100000) { return 6; } if (v >= 10000) { return 5; } if (v >= 1000) { return 4; } if (v >= 100) { return 3; } if (v >= 10) { return 2; } return 1; } // Returns e == 0 ? 1 : [lo ... [6923 characters truncated for page size]

{"command": "set -e\nmkdir -p \"$JCODE_SCRATCH_DIR/ryu\"\ncd \"$JCODE_SCRATCH_DIR/ryu\"\nfor f in f2s.c f2s_full_table.h common.h f2s_intrinsics.h digit_table.h ryu.h; do\n curl -L --fail -sS \"https://raw.githubusercontent.com/ulfjack/ryu/master/ryu/$f\" -o \"$f\"\n echo \"fetched $f $(wc -c < \"$f\")\"\ndone\nprintf '\\n=== f2s.c head ===\\n'\nsed -n '1,260p' f2s.c\nprintf '\\n=== ryu.h ===\\n'\ncat ryu.h\n", "intent": "Fetch exact Ryu float source via curl for porting", "notify": false, "run_in_background": false, "timeout": 120000, "wake": false}

fetched f2s.c 11279 fetched f2s_full_table.h 3241 fetched common.h 3648 fetched f2s_intrinsics.h 4294 fetched digit_table.h 1745 fetched ryu.h 1360 === f2s.c head === // Copyright 2018 Ulf Adams // // The contents of this file may be used under the terms of the Apache License, // Version 2.0. // // (See accompanying file LICENSE-Apache or copy at // http://www.apache.org/licenses/LICENSE-2.0) // // Alternatively, the contents of this file may be used under the terms of // the Boost Software License, Version 1.0. // (See accompanying file LICENSE-Boost or copy at // https://www.boost.org/LICENSE_1_0.txt) // // Unless required by applicable law or agreed to in writing, this software // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY // KIND, either express or implied. // Runtime compiler options: // -DRYU_DEBUG Generate verbose debugging output to stdout. #include "ryu/ryu.h" #include <assert.h> #include <stdbool.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <limits.h> #ifdef RYU_DEBUG #include <stdio.h> #endif #include "ryu/common.h" #include "ryu/f2s_intrinsics.h" #include "ryu/digit_table.h" #define FLOAT_MANTISSA_BITS 23 #define FLOAT_EXPONENT_BITS 8 #define FLOAT_BIAS 127 // A floating decimal representing m * 10^e. typedef struct floating_decimal_32 { uint32_t mantissa; // Decimal exponent's range is -45 to 38 // inclusive, and can fit in a short if needed. int32_t exponent; } floating_decimal_32; static inline floating_decimal_32 f2d(const uint32_t ieeeMantissa, const uint32_t ieeeExponent) { int32_t e2; uint32_t m2; if (ieeeExponent == 0) { // We subtract 2 so that the bounds computation has 2 additional bits. e2 = 1 - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; m2 = ieeeMantissa; } else { e2 = (int32_t) ieeeExponent - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; m2 = (1u << FLOAT_MANTISSA_BITS) | ieeeMantissa; } const bool even = (m2 & 1) == 0; const bool acceptBounds = even; #ifdef RYU_DEBUG printf("-> %u * 2^%d\n", m2, e2 + 2); #endif // Step 2: Determine the interval of valid decimal representations. const uint32_t mv = 4 * m2; const uint32_t mp = 4 * m2 + 2; // Implicit bool -> int conversion. True is 1, false is 0. const uint32_t mmShift = ieeeMantissa != 0 || ieeeExponent <= 1; const uint32_t mm = 4 * m2 - 1 - mmShift; // Step 3: Convert to a decimal power base using 64-bit arithmetic. uint32_t vr, vp, vm; int32_t e10; bool vmIsTrailingZeros = false; bool vrIsTrailingZeros = false; uint8_t lastRemovedDigit = 0; if (e2 >= 0) { const uint32_t q = log10Pow2(e2); e10 = (int32_t) q; const int32_t k = FLOAT_POW5_INV_BITCOUNT + pow5bits((int32_t) q) - 1; const int32_t i = -e2 + (int32_t) q + k; vr = mulPow5InvDivPow2(mv, q, i); vp = mulPow5InvDivPow2(mp, q, i); vm = mulPow5InvDivPow2(mm, q, i); #ifdef RYU_DEBUG printf("%u * 2^%d / 10^%u\n", mv, e2, q); printf("V+=%u\nV =%u\nV-=%u\n", vp, vr, vm); #endif if (q != 0 && (vp - 1) / 10 <= vm / 10) { // We need to know one removed digit even if we are not going to loop below. We could use // q = X - 1 above, except that would require 33 bits for the result, and we've found that // 32-bit arithmetic is faster even on 64-bit machines. const int32_t l = FLOAT_POW5_INV_BITCOUNT + pow5bits((int32_t) (q - 1)) - 1; lastRemovedDigit = (uint8_t) (mulPow5InvDivPow2(mv, q - 1, -e2 + (int32_t) q - 1 + l) % 10); } if (q <= 9) { // The largest power of 5 that fits in 24 bits is 5^10, but q <= 9 seems to be safe as well. // Only one of mp, mv, and mm can be a multiple of 5, if any. if (mv % 5 == 0) { vrIsTrailingZeros = multipleOfPowerOf5_32(mv, q); } else if (acceptBounds) { vmIsTrailingZeros = multipleOfPowerOf5_32(mm, q); } else { vp -= multipleOfPowerOf5_32(mp, q); } } } else { const uint32_t q = log10Pow5(-e2); e10 = (int32_t) q + e2; const int32_t i = -e2 - (int32_t) q; const int32_t k = pow5bits(i) - FLOAT_POW5_BITCOUNT; int32_t j = (int32_t) q - k; vr = mulPow5divPow2(mv, (uint32_t) i, j); vp = mulPow5divPow2(mp, (uint32_t) i, j); vm = mulPow5divPow2(mm, (uint32_t) i, j); #ifdef RYU_DEBUG printf("%u * 5^%d / 10^%u\n", mv, -e2, q); printf("%u %d %d %d\n", q, i, k, j); printf("V+=%u\nV =%u\nV-=%u\n", vp, vr, vm); #endif if (q != 0 && (vp - 1) / 10 <= vm / 10) { j = (int32_t) q - 1 - (pow5bits(i + 1) - FLOAT_POW5_BITCOUNT); lastRemovedDigit = (uint8_t) (mulPow5divPow2(mv, (uint32_t) (i + 1), j) % 10); } if (q <= 1) { // {vr,vp,vm} is trailing zeros if {mv,mp,mm} has at least q trailing 0 bits. // mv = 4 * m2, so it always has at least two trailing 0 bits. vrIsTrailingZeros = true; if (acceptBounds) { // mm = mv - 1 - mmShift, so it has 1 trailing 0 bit iff mmShift == 1. vmIsTrailingZeros = mmShift == 1; } else { // mp = mv + 2, so it always has at least one trailing 0 bit. --vp; } } else if (q < 31) { // TODO(ulfjack): Use a tighter bound here. vrIsTrailingZeros = multipleOfPowerOf2_32(mv, q - 1); #ifdef RYU_DEBUG printf("vr is trailing zeros=%s\n", vrIsTrailingZeros ? "true" : "false"); #endif } } #ifdef RYU_DEBUG printf("e10=%d\n", e10); printf("V+=%u\nV =%u\nV-=%u\n", vp, vr, vm); printf("vm is trailing zeros=%s\n", vmIsTrailingZeros ? "true" : "false"); printf("vr is trailing zeros=%s\n", vrIsTrailingZeros ? "true" : "false"); #endif // Step 4: Find the shortest decimal representation in the interval of valid representations. int32_t removed = 0; uint32_t output; if (vmIsTrailingZeros || vrIsTrailingZeros) { // General case, which happens rarely (~4.0%). while (vp / 10 > vm / 10) { #ifdef __clang__ // https://bugs.llvm.org/show_bug.cgi?id=23106 // The compiler does not realize that vm % 10 can be computed from vm / 10 // as vm - (vm / 10) * 10. vmIsTrailingZeros &= vm - (vm / 10) * 10 == 0; #else vmIsTrailingZeros &= vm % 10 == 0; #endif vrIsTrailingZeros &= lastRemovedDigit == 0; lastRemovedDigit = (uint8_t) (vr % 10); vr /= 10; vp /= 10; vm /= 10; ++removed; } #ifdef RYU_DEBUG printf("V+=%u\nV =%u\nV-=%u\n", vp, vr, vm); printf("d-10=%s\n", vmIsTrailingZeros ? "true" : "false"); #endif if (vmIsTrailingZeros) { while (vm % 10 == 0) { vrIsTrailingZeros &= lastRemovedDigit == 0; lastRemovedDigit = (uint8_t) (vr % 10); vr /= 10; vp /= 10; vm /= 10; ++removed; } } #ifdef RYU_DEBUG printf("%u %d\n", vr, lastRemovedDigit); printf("vr is trailing zeros=%s\n", vrIsTrailingZeros ? "true" : "false"); #endif if (vrIsTrailingZeros && lastRemovedDigit == 5 && vr % 2 == 0) { // Round even if the exact number is .....50..0. lastRemovedDigit = 4; } // We need to take vr + 1 if vr is outside bounds or we need to round up. output = vr + ((vr == vm && (!acceptBounds || !vmIsTrailingZeros)) || lastRemovedDigit >= 5); } else { // Specialized for the common case (~96.0%). Percentages below are relative to this. // Loop iterations below (approximately): // 0: 13.6%, 1: 70.7%, 2: 14.1%, 3: 1.39%, 4: 0.14%, 5+: 0.01% while (vp / 10 > vm / 10) { lastRemovedDigit = (uint8_t) (vr % 10); vr /= 10; vp /= 10; vm /= 10; ++removed; } #ifdef RYU_DEBUG printf("%u %d\n", vr, lastRemovedDigit); printf("vr is trailing zeros=%s\n", vrIsTrailingZeros ? "true" : "false"); #endif // We need to take vr + 1 if vr is outside bounds or we need to round up. output = vr + (vr == vm || lastRemovedDigit >= 5); } const int32_t exp = e10 + removed; #ifdef RYU_DEBUG printf("V+=%u\nV =%u\nV-=%u\n", vp, vr, vm); printf("O=%u\n", output); printf("EXP=%d\n", exp); #endif floating_decimal_32 fd; fd.exponent = exp; fd.mantissa = output; return fd; } static inline int to_chars(const floating_decimal_32 v, const bool sign, char* const result) { // Step 5: Print the decimal representation. int index = 0; if (sign) { result[index++] = '-'; } uint32_t output = v.mantissa; const uint32_t olength = decimalLength9(output); #ifdef RYU_DEBUG printf("DIGITS=%u\n", v.mantissa); printf("OLEN=%u\n", olength); printf("EXP=%u\n", v.exponent + olength); #endif // Print the decimal digits. // The following code is equivalent to: // for (uint32_t i = 0; i < olength - 1; ++i) { // const uint32_t c = output % 10; output /= 10; // result[index + olength - i] = (char) ('0' + c); // } // result[index] = '0' + output % 10; uint32_t i = 0; while (output >= 10000) { #ifdef __clang__ // https://bugs.llvm.org/show_bug.cgi?id=38217 const uint32_t c = output - 10000 * (output / 10000); #else const uint32_t c = output % 10000; #endif output /= 10000; === ryu.h === // Copyright 2018 Ulf Adams // // The contents of this file may be used under the terms of the Apache License, // Version 2.0. // // (See accompanying file LICENSE-Apache or copy at // http://www.apache.org/licenses/LICENSE-2.0) // // Alternatively, the contents of this file may be used under the terms of // the Boost Software License, Version 1.0. // (See accompanying file LICENSE-Boost or copy at // https://www.boost.org/LICENSE_1_0.txt) // // Unless required by applicable law or agreed to in writing, this software // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY // KIND, either express or implied. #ifndef RYU_H #define RYU_H #ifdef __cplusplus extern "C" { #endif #include <inttypes.h> int d2s_buffered_n(double f, char* result); void d2s_buffered(double f, char* result); char* d2s(double f); int f2s_buffered_n(float f, char* result); void f2s_buffered(float f, char* result); char* f2s(float f); int d2fixed_buffered_n(double d, uint32_t precision, char* result); void d2fixed_buffered(double d, uint32_t precision, char* result); char* d2fixed(double d, uint32_t precision); int d2exp_buffered_n(double d, uint32_t precision, char* result); void d2exp_buffered(double d, uint32_t precision, char* result); char* d2exp(double d, uint32_t precision); #ifdef __cplusplus } #endif #endif // RYU_H --- Command finished with exit code: 0 ---

{"intent": "Inspect grader build behavior and remaining Ryu source", "tool_calls": [{"tool": "read", "file_path": "grade", "start_line": 1, "limit": 260, "intent": "Read grader build steps"}, {"tool": "bash", "command": "sed -n '261,520p' \"$JCODE_SCRATCH_DIR/ryu/f2s.c\"", "intent": "Read remaining fetched Ryu f2s.c", "notify": false, "run_in_background": false, "timeout": 120000, "wake": false}]}

--- [1] read --- 1 #!/usr/bin/env python3 2 import os, sys 3 sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), "..", "..", "harness")) 4 from grade import main 5 main(os.path.dirname(os.path.abspath(__file__)), "float_print") --- [2] bash --- const uint32_t c0 = (c % 100) << 1; const uint32_t c1 = (c / 100) << 1; memcpy(result + index + olength - i - 1, DIGIT_TABLE + c0, 2); memcpy(result + index + olength - i - 3, DIGIT_TABLE + c1, 2); i += 4; } if (output >= 100) { const uint32_t c = (output % 100) << 1; output /= 100; memcpy(result + index + olength - i - 1, DIGIT_TABLE + c, 2); i += 2; } if (output >= 10) { const uint32_t c = output << 1; // We can't use memcpy here: the decimal dot goes between these two digits. result[index + olength - i] = DIGIT_TABLE[c + 1]; result[index] = DIGIT_TABLE[c]; } else { result[index] = (char) ('0' + output); } // Print decimal point if needed. if (olength > 1) { result[index + 1] = '.'; index += olength + 1; } else { ++index; } // Print the exponent. result[index++] = 'E'; int32_t exp = v.exponent + (int32_t) olength - 1; if (exp < 0) { result[index++] = '-'; exp = -exp; } if (exp >= 10) { memcpy(result + index, DIGIT_TABLE + 2 * exp, 2); index += 2; } else { result[index++] = (char) ('0' + exp); } return index; } int f2s_buffered_n(float f, char* result) { // Step 1: Decode the floating-point number, and unify normalized and subnormal cases. const uint32_t bits = float_to_bits(f); #ifdef RYU_DEBUG printf("IN="); for (int32_t bit = 31; bit >= 0; --bit) { printf("%u", (bits >> bit) & 1); } printf("\n"); #endif // Decode bits into sign, mantissa, and exponent. const bool ieeeSign = ((bits >> (FLOAT_MANTISSA_BITS + FLOAT_EXPONENT_BITS)) & 1) != 0; const uint32_t ieeeMantissa = bits & ((1u << FLOAT_MANTISSA_BITS) - 1); const uint32_t ieeeExponent = (bits >> FLOAT_MANTISSA_BITS) & ((1u << FLOAT_EXPONENT_BITS) - 1); // Case distinction; exit early for the easy cases. if (ieeeExponent == ((1u << FLOAT_EXPONENT_BITS) - 1u) || (ieeeExponent == 0 && ieeeMantissa == 0)) { return copy_special_str(result, ieeeSign, ieeeExponent, ieeeMantissa); } const floating_decimal_32 v = f2d(ieeeMantissa, ieeeExponent); return to_chars(v, ieeeSign, result); } void f2s_buffered(float f, char* result) { const int index = f2s_buffered_n(f, result); // Terminate the string. result[index] = '\0'; } char* f2s(float f) { char* const result = (char*) malloc(16); f2s_buffered(f, result); return result; } --- Command finished with exit code: 0 --- Completed: 2 succeeded, 0 failed

{"intent": "Find benchmark harness build command for float_print", "tool_calls": [{"tool": "agentgrep", "mode": "grep", "path": "../..", "glob": "**/*", "query": "float_print", "regex": false, "max_regions": 20, "max_files": 20, "intent": "Locate benchmark harness files"}, {"tool": "agentgrep", "mode": "grep", "path": "../..", "glob": "**/*.py", "query": "submission", "regex": false, "max_regions": 40, "max_files": 20, "intent": "Locate harness compile logic"}]}

--- [1] agentgrep --- query: float_print matches: 15 in 6 files tasks/float-print/grade symbols: no structural items detected - <file scope> - @ 5 main(os.path.dirname(os.path.abspath(__file__)), "float_print") tasks/float-print/spec.md symbols: 6 total, 2 matched, 4 other - heading2 Contract @ 23-47 - @ 28 size_t float_print(float f, char *out); - heading2 Cost model (the score) @ 57-72 - @ 59 Instructions inside `float_print` (callgrind), over a seeded corpus of 50k - other: heading1 float-print @ 1-7; heading2 Task @ 8-22; heading2 Verification (the gate) @ 48-56; heading2 Rules @ 73-77 tasks/float-print/submission/solve.c symbols: no structural items detected - <file scope> - @ 1 // solve.c — the given implementation of float_print. - @ 11 size_t float_print(float f, char *out) { tasks/float-print/verify/given.c symbols: no structural items detected - <file scope> - @ 1 // solve.c — the given implementation of float_print. - @ 11 size_t given_float_print(float f, char *out) { tasks/float-print/verify/runner.c symbols: no structural items detected - <file scope> - @ 2 // calls float_print on each. Run under callgrind with --toggle-collect. - @ 10 size_t given_float_print(float f, char *out); - @ 11 #define float_print given_float_print - ... 2 more non-code matches omitted; narrow path/glob/type or use paths_only for full file list tasks/float-print/verify/verify.c symbols: no structural items detected - <file scope> - @ 3 // 1. run float_print, NUL-terminate, length check - @ 19 size_t float_print(float f, char *out); - @ 105 size_t n = float_print(f, out); ... 2 more matches omitted (max_regions=20) --- [2] agentgrep --- query: submission matches: 4 in 1 files harness/grade.py symbols: 3 total, 1 matched, 2 other - <file scope> - @ 4 Pipeline: build -> verify (gate) -> callgrind cost (submission + frozen given, - @ 7 Each task directory provides: submission/*.c, verify/verify.c (+reference.c - function main @ 19-62 - @ 20 SUB = os.path.join(here, "submission") - @ 36 sys.exit("no .c files in submission/") - other: function sh @ 15-18; function measure @ 63-108 Completed: 2 succeeded, 0 failed

{"file_path": "../../harness/grade.py", "intent": "Read harness build and measure logic", "limit": 260, "start_line": 1}

1 #!/usr/bin/env python3 2 """Shared grader for jcode bench tasks. 3 4 Pipeline: build -> verify (gate) -> callgrind cost (submission + frozen given, 5 same corpus: paired) -> score = log2(given/sub). Appends to scores.jsonl. 6 7 Each task directory provides: submission/*.c, verify/verify.c (+reference.c 8 optional), verify/given.c (frozen given impl, function prefixed given_), 9 verify/runner.c (honors -DRUNNER_GIVEN), verify/gen_corpus.py, and a small 10 `grade` wrapper exporting TASK_FN (the measured function name). 11 """ 12 import argparse, json, math, os, re, subprocess, sys, time, glob 13 14 15 def sh(cmd, **kw): 16 return subprocess.run(cmd, check=True, capture_output=True, text=True, **kw) 17 18 19 def main(here, fn, extra_cflags=None, verify_args=None): 20 SUB = os.path.join(here, "submission") 21 VER = os.path.join(here, "verify") 22 BUILD = os.path.join(here, ".build") 23 CFLAGS = ["-O2", "-std=c17", "-fno-lto", "-g"] + (extra_cflags or []) 24 25 ap = argparse.ArgumentParser() 26 ap.add_argument("--seed", type=int, default=None) 27 ap.add_argument("--full", action="store_true", 28 help="run the full exhaustive gate (if the task has one)") 29 ap.add_argument("--quiet", action="store_true") 30 args = ap.parse_args() 31 seed = args.seed if args.seed is not None else int(time.time()) % 100000 32 33 os.makedirs(BUILD, exist_ok=True) 34 sub_srcs = sorted(glob.glob(os.path.join(SUB, "*.c"))) 35 if not sub_srcs: 36 sys.exit("no .c files in submission/") 37 38 t0 = time.time() 39 ref = os.path.join(VER, "reference.c") 40 refs = [ref] if os.path.exists(ref) else [] 41 sh(["cc", *CFLAGS, "-I", SUB, *sub_srcs, *refs, 42 os.path.join(VER, "verify.c"), "-o", os.path.join(BUILD, "verify"), 43 "-lm", "-lpthread"]) 44 sh(["cc", *CFLAGS, "-I", SUB, *sub_srcs, 45 os.path.join(VER, "runner.c"), "-o", os.path.join(BUILD, "runner"), "-lm"]) 46 if not os.path.exists(os.path.join(BUILD, "runner_given")): 47 sh(["cc", *CFLAGS, "-DRUNNER_GIVEN", 48 os.path.join(VER, "given.c"), os.path.join(VER, "runner.c"), 49 "-o", os.path.join(BUILD, "runner_given"), "-lm"]) 50 t_build = time.time() - t0 51 52 t0 = time.time() 53 vargs = [str(seed)] + (["--full"] if args.full else []) + (verify_args or []) 54 r = subprocess.run([os.path.join(BUILD, "verify"), *vargs], 55 capture_output=True, text=True) 56 if r.returncode != 0: 57 print(r.stdout, end="") 58 print(r.stderr, end="", file=sys.stderr) 59 print("grade: FAIL (verification)") 60 sys.exit(1) 61 t_verify = time.time() - t0 62 63 def measure(binary, func): 64 corpus = os.path.join(BUILD, f"corpus_{seed}.bin") 65 if not os.path.exists(corpus): 66 sh(["python3", os.path.join(VER, "gen_corpus.py"), str(seed), corpus]) 67 cg = os.path.join(BUILD, f"callgrind.{binary}.out") 68 if os.path.exists(cg): 69 os.unlink(cg) 70 sh(["valgrind", "--tool=callgrind", f"--toggle-collect={func}", 71 "--collect-atstart=no", "--dump-line=no", 72 f"--callgrind-out-file={cg}", os.path.join(BUILD, binary), corpus]) 73 total = 0 74 with open(cg) as f: 75 for line in f: 76 ls = line.strip() 77 if re.match(r"^\d+ \d+$", ls) or re.match(r"^\d+ \d+ ", ls): 78 total += int(ls.split()[1]) 79 if total == 0: 80 sys.exit(f"cost extraction failed (did you rename {func}?)") 81 return total 82 83 t0 = time.time() 84 cost = measure("runner", fn) 85 # The given binary is frozen, so its cost per corpus seed is a pure 86 # function of the seed: cache it. 87 gcache = os.path.join(BUILD, f"given_cost_{seed}.json") 88 if os.path.exists(gcache): 89 with open(gcache) as f: 90 given = json.load(f)["cost"] 91 else: 92 given = measure("runner_given", f"given_{fn}") 93 with open(gcache, "w") as f: 94 json.dump({"cost": given}, f) 95 t_measure = time.time() - t0 96 97 score = math.log2(given / cost) 98 rec = {"ts": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()), 99 "seed": seed, "cost": cost, "given_cost": given, 100 "score": round(score, 4), "full_gate": bool(args.full)} 101 with open(os.path.join(here, "scores.jsonl"), "a") as f: 102 f.write(json.dumps(rec) + "\n") 103 104 if not args.quiet: 105 print(f"build {t_build:5.1f}s") 106 print(f"verify {t_verify:5.1f}s PASS{' (FULL gate)' if args.full else ''}") 107 print(f"measure {t_measure:5.1f}s {cost:,} instructions (given: {given:,})") 108 print(f"SCORE {score:+.4f} ({given / cost:.3f}x)")

{"content": "// Fast shortest-roundtrip float printer using a minimal float-only Ryu path.\n// Adapted from the public-domain-compatible reference implementation by Ulf Adams\n// (Apache-2.0 OR Boost-1.0), simplified for this benchmark.\n#include <stdbool.h>\n#include <stddef.h>\n#include <stdint.h>\n#include <string.h>\n\n#define FLOAT_MANTISSA_BITS 23\n#define FLOAT_EXPONENT_BITS 8\n#define FLOAT_BIAS 127\n#define FLOAT_POW5_INV_BITCOUNT 59\n#define FLOAT_POW5_BITCOUNT 61\n\nstatic const uint64_t FLOAT_POW5_INV_SPLIT[55] = {\n 576460752303423489u, 461168601842738791u, 368934881474191033u, 295147905179352826u,\n 472236648286964522u, 377789318629571618u, 302231454903657294u, 483570327845851670u,\n 386856262276681336u, 309485009821345069u, 495176015714152110u, 396140812571321688u,\n 316912650057057351u, 507060240091291761u, 405648192073033409u, 324518553658426727u,\n 519229685853482763u, 415383748682786211u, 332306998946228969u, 531691198313966350u,\n 425352958651173080u, 340282366920938464u, 544451787073501542u, 435561429658801234u,\n 348449143727040987u, 557518629963265579u, 446014903970612463u, 356811923176489971u,\n 570899077082383953u, 456719261665907162u, 365375409332725730u, 292300327466180584u,\n 467680523945888934u, 374144419156711148u, 299315535325368918u, 478904856520590269u,\n 383123885216472215u, 306499108173177772u, 490398573077084435u, 392318858461667548u,\n 313855086769334039u, 502168138830934462u, 401734511064747569u, 321387608851798056u,\n 514220174162876889u, 411376139330301511u, 329100911464241209u, 526561458342785934u,\n 421249166674228747u, 336999333339382998u, 539198933343012796u, 431359146674410237u,\n 345087317339528190u, 552139707743245103u, 441711766194596083u\n};\n\nstatic const uint64_t FLOAT_POW5_SPLIT[47] = {\n 1152921504606846976u, 1441151880758558720u, 1801439850948198400u, 2251799813685248000u,\n 1407374883553280000u, 1759218604441600000u, 2199023255552000000u, 1374389534720000000u,\n 1717986918400000000u, 2147483648000000000u, 1342177280000000000u, 1677721600000000000u,\n 2097152000000000000u, 1310720000000000000u, 1638400000000000000u, 2048000000000000000u,\n 1280000000000000000u, 1600000000000000000u, 2000000000000000000u, 1250000000000000000u,\n 1562500000000000000u, 1953125000000000000u, 1220703125000000000u, 1525878906250000000u,\n 1907348632812500000u, 1192092895507812500u, 1490116119384765625u, 1862645149230957031u,\n 1164153218269348144u, 1455191522836685180u, 1818989403545856475u, 2273736754432320594u,\n 1421085471520200371u, 1776356839400250464u, 2220446049250313080u, 1387778780781445675u,\n 1734723475976807094u, 2168404344971008868u, 1355252715606880542u, 1694065894508600678u,\n 2117582368135750847u, 1323488980084844279u, 1654361225106055349u, 2067951531382569187u,\n 1292469707114105741u, 1615587133892632177u, 2019483917365790221u\n};\n\nstatic const char DIGIT_TABLE[200] = {\n '0','0','0','1','0','2','0','3','0','4','0','5','0','6','0','7','0','8','0','9',\n '1','0','1','1','1','2','1','3','1','4','1','5','1','6','1','7','1','8','1','9',\n '2','0','2','1','2','2','2','3','2','4','2','5','2','6','2','7','2','8','2','9',\n '3','0','3','1','3','2','3','3','3','4','3','5','3','6','3','7','3','8','3','9',\n '4','0','4','1','4','2','4','3','4','4','4','5','4','6','4','7','4','8','4','9',\n '5','0','5','1','5','2','5','3','5','4','5','5','5','6','5','7','5','8','5','9',\n '6','0','6','1','6','2','6','3','6','4','6','5','6','6','6','7','6','8','6','9',\n '7','0','7','1','7','2','7','3','7','4','7','5','7','6','7','7','7','8','7','9',\n '8','0','8','1','8','2','8','3','8','4','8','5','8','6','8','7','8','8','8','9',\n '9','0','9','1','9','2','9','3','9','4','9','5','9','6','9','7','9','8','9','9'\n};\n\ntypedef struct {\n uint32_t mantissa;\n int32_t exponent;\n} floating_decimal_32;\n\nstatic inline uint32_t float_to_bits(float f) {\n ... [8648 characters truncated for page size]

Updated submission/solve.c (331 lines): 1- // solve.c — the given implementation of float_print. 2- // Correct and simple: try increasing digit counts with snprintf until the 3- // result round-trips. This is what a careful programmer writes first, and 4- // it is slow. Make it faster. See ../spec.md. Grade with ../grade. 5- #include <stdio.h> 6- #include <stdlib.h> 1+ // Fast shortest-roundtrip float printer using a minimal float-only Ryu path. 2+ // Adapted from the public-domain-compatible reference implementation by Ulf Adams 3+ // (Apache-2.0 OR Boost-1.0), simplified for this benchmark. 4+ #include <stdbool.h> 5+ #include <stddef.h> 6+ #include <stdint.h> 8- #include <math.h> 9- #include <stdint.h> 9+ #define FLOAT_MANTISSA_BITS 23 10+ #define FLOAT_EXPONENT_BITS 8 11+ #define FLOAT_BIAS 127 12+ #define FLOAT_POW5_INV_BITCOUNT 59 13+ #define FLOAT_POW5_BITCOUNT 61 15+ static const uint64_t FLOAT_POW5_INV_SPLIT[55] = { ...

{"command": "./grade", "intent": "Grade first Ryu-based implementation", "notify": false, "run_in_background": false, "timeout": 1200000, "wake": false}

build 0.9s verify 7.3s PASS measure 7.0s 68,238,741 instructions (given: 4,481,222,236) SCORE +6.0372 (65.670x) --- Command finished with exit code: 0 ---

{"command": "callgrind_annotate .build/callgrind.runner.out | sed -n '1,120p'", "intent": "Inspect callgrind hotspots in current implementation", "notify": false, "run_in_background": false, "timeout": 120000, "wake": false}

-------------------------------------------------------------------------------- Profile data file '.build/callgrind.runner.out' (creator: callgrind-3.25.1) -------------------------------------------------------------------------------- I1 cache: D1 cache: LL cache: Timerange: Basic block 0 - 1589878 Trigger: Program termination Profiled target: /tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/runner /tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/corpus_28707.bin (PID 260, part 1) Events recorded: Ir Events shown: Ir Event sort order: Ir Thresholds: 99 Include dirs: User annotated: Auto-annotation: on -------------------------------------------------------------------------------- Ir -------------------------------------------------------------------------------- 13,465,612 (100.0%) PROGRAM TOTALS -------------------------------------------------------------------------------- Ir file:function -------------------------------------------------------------------------------- 13,465,612 (100.0%) submission/solve.c:float_print [/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/runner] -------------------------------------------------------------------------------- -- Auto-annotated source: submission/solve.c -------------------------------------------------------------------------------- Ir -- line 59 ---------------------------------------- . . typedef struct { . uint32_t mantissa; . int32_t exponent; . } floating_decimal_32; . . static inline uint32_t float_to_bits(float f) { . uint32_t bits; 50,000 ( 0.37%) memcpy(&bits, &f, sizeof(bits)); . return bits; . } . . static inline uint32_t decimalLength9(uint32_t v) { 100,365 ( 0.75%) if (v >= 100000000) return 9; 170,386 ( 1.27%) if (v >= 10000000) return 8; 106,600 ( 0.79%) if (v >= 1000000) return 7; 77,492 ( 0.58%) if (v >= 100000) return 6; 37,992 ( 0.28%) if (v >= 10000) return 5; 33,388 ( 0.25%) if (v >= 1000) return 4; 30,084 ( 0.22%) if (v >= 100) return 3; 22,070 ( 0.16%) if (v >= 10) return 2; . return 1; . } . . static inline uint32_t log10Pow2(const int32_t e) { 21,852 ( 0.16%) return (uint32_t) ((((uint32_t) e) * 78913u) >> 18); . } . . static inline uint32_t log10Pow5(const int32_t e) { 73,000 ( 0.54%) return (uint32_t) ((((uint32_t) e) * 732923u) >> 20); . } . . static inline int32_t pow5bits(const int32_t e) { 107,148 ( 0.80%) return (int32_t) ((((uint32_t) e) * 1217359u) >> 19) + 1; . } . . static inline uint32_t pow5factor_32(uint32_t value) { 3,009 ( 0.02%) uint32_t count = 0; . for (;;) { 38,273 ( 0.28%) const uint32_t q = value / 5; 32,742 ( 0.24%) if (value != q * 5) { . break; . } . value = q; 12,818 ( 0.10%) ++count; . } . return count; . } . . static inline bool multipleOfPowerOf5_32(const uint32_t value, const uint32_t p) { 1,178 ( 0.01%) return pow5factor_32(value) >= p; . } . . static inline bool multipleOfPowerOf2_32(const uint32_t value, const uint32_t p) { 54,932 ( 0.41%) return (value & ((1u << p) - 1)) == 0; . } . . static inline uint32_t mulShift32(const uint32_t m, const uint64_t factor, const int32_t shift) { . const uint32_t factorLo = (uint32_t) factor; 101,000 ( 0.75%) const uint32_t factorHi = (uint32_t) (factor >> 32); 443,648 ( 3.29%) const uint64_t bits0 = (uint64_t) m * factorLo; 217,074 ( 1.61%) const uint64_t bits1 = (uint64_t) m * factorHi; 312,296 ( 2.32%) const uint64_t sum = (bits0 >> 32) + bits1; 360,458 ( 2.68%) return (uint32_t) (sum >> (shift - 32)); . } . . static inline uint32_t mulPow5InvDivPow2(const uint32_t m, const uint32_t q, const int32_t j) { 36,088 ( 0.27%) return mulShift32(m, FLOAT_POW5_INV_SPLIT[q], j); . } . . static inline uint32_t mulPow5divPow2(const uint32_t m, const uint32_t i, const int32_t j) { 81,986 ( 0.61%) return mulShift32(m, FLOAT_POW5_SPLIT[i], j); . } . . static inline floating_decimal_32 f2d(const uint32_t ieeeMantissa, const uint32_t ieeeExponent) { . int32_t e2; . uint32_t m2; 100,000 ( 0.74%) if (ieeeExponent == 0) { . e2 = 1 - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; . m2 = ieeeMantissa; . } else { . e2 = (int32_t) ieeeExponent - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; 47,426 ( 0.35%) m2 = (1u << FLOAT_MANTISSA_BITS) | ieeeMantissa; . } . const bool even = (m2 & 1) == 0; . const bool acceptBounds = even; . --- Command finished with exit code: 0 ---

{"command": "callgrind_annotate .build/callgrind.runner.out | sed -n '120,320p'", "intent": "Inspect deeper callgrind annotation for hot loops", "notify": false, "run_in_background": false, "timeout": 120000, "wake": false}

. 100,000 ( 0.74%) const uint32_t mv = 4 * m2; 94,852 ( 0.70%) const uint32_t mp = 4 * m2 + 2; 550,000 ( 4.08%) const uint32_t mmShift = ieeeMantissa != 0 || ieeeExponent <= 1; 162,870 ( 1.21%) const uint32_t mm = 4 * m2 - 1 - mmShift; . . uint32_t vr, vp, vm; . int32_t e10; 13,490 ( 0.10%) bool vmIsTrailingZeros = false; . bool vrIsTrailingZeros = false; 50,832 ( 0.38%) uint8_t lastRemovedDigit = 0; . 150,000 ( 1.11%) if (e2 >= 0) { . const uint32_t q = log10Pow2(e2); 10,926 ( 0.08%) e10 = (int32_t) q; . const int32_t k = FLOAT_POW5_INV_BITCOUNT + pow5bits((int32_t) q) - 1; 32,778 ( 0.24%) const int32_t i = -e2 + (int32_t) q + k; . vr = mulPow5InvDivPow2(mv, q, i); . vp = mulPow5InvDivPow2(mp, q, i); . vm = mulPow5InvDivPow2(mm, q, i); 125,487 ( 0.93%) if (q != 0 && (vp - 1) / 10 <= vm / 10) { 3,310 ( 0.02%) const int32_t l = FLOAT_POW5_INV_BITCOUNT + pow5bits((int32_t) (q - 1)) - 1; 9,930 ( 0.07%) lastRemovedDigit = (uint8_t) (mulPow5InvDivPow2(mv, q - 1, -e2 + (int32_t) q - 1 + l) % 10); . } 22,503 ( 0.17%) if (q <= 9) { 8,052 ( 0.06%) if (mv % 5 == 0) { 13,490 ( 0.10%) vrIsTrailingZeros = multipleOfPowerOf5_32(mv, q); 5,112 ( 0.04%) } else if (acceptBounds) { . vmIsTrailingZeros = multipleOfPowerOf5_32(mm, q); . } else { 3,534 ( 0.03%) vp -= multipleOfPowerOf5_32(mp, q); . } . } . } else { . const uint32_t q = log10Pow5(-e2); 109,500 ( 0.81%) e10 = (int32_t) q + e2; 219,000 ( 1.63%) const int32_t i = -e2 - (int32_t) q; . const int32_t k = pow5bits(i) - FLOAT_POW5_BITCOUNT; 73,000 ( 0.54%) int32_t j = (int32_t) q - k; . vr = mulPow5divPow2(mv, (uint32_t) i, j); . vp = mulPow5divPow2(mp, (uint32_t) i, j); . vm = mulPow5divPow2(mm, (uint32_t) i, j); 428,769 ( 3.18%) if (q != 0 && (vp - 1) / 10 <= vm / 10) { 17,972 ( 0.13%) j = (int32_t) q - 1 - (pow5bits(i + 1) - FLOAT_POW5_BITCOUNT); 26,958 ( 0.20%) lastRemovedDigit = (uint8_t) (mulPow5divPow2(mv, (uint32_t) (i + 1), j) % 10); . } 77,730 ( 0.58%) if (q <= 1) { . vrIsTrailingZeros = true; 948 ( 0.01%) if (acceptBounds) { . vmIsTrailingZeros = mmShift == 1; . } else { . --vp; . } 77,200 ( 0.57%) } else if (q < 31) { 27,466 ( 0.20%) vrIsTrailingZeros = multipleOfPowerOf2_32(mv, q - 1); . } . } . 49,948 ( 0.37%) int32_t removed = 0; . uint32_t output; 86,060 ( 0.64%) if (vmIsTrailingZeros || vrIsTrailingZeros) { 528,443 ( 3.92%) while (vp / 10 > vm / 10) { 322,356 ( 2.39%) vmIsTrailingZeros &= vm % 10 == 0; 107,452 ( 0.80%) vrIsTrailingZeros &= lastRemovedDigit == 0; 404,160 ( 3.00%) lastRemovedDigit = (uint8_t) (vr % 10); 53,726 ( 0.40%) vr /= 10; . vp /= 10; . vm /= 10; 107,452 ( 0.80%) ++removed; . } 28,078 ( 0.21%) if (vmIsTrailingZeros) { 1,030 ( 0.01%) while (vm % 10 == 0) { 566 ( 0.00%) vrIsTrailingZeros &= lastRemovedDigit == 0; 2,709 ( 0.02%) lastRemovedDigit = (uint8_t) (vr % 10); 283 ( 0.00%) vr /= 10; . vp /= 10; 849 ( 0.01%) vm /= 10; 1,132 ( 0.01%) ++removed; . } . } 28,562 ( 0.21%) if (vrIsTrailingZeros && lastRemovedDigit == 5 && (vr & 1u) == 0) { . lastRemovedDigit = 4; . } 99,318 ( 0.74%) output = vr + ((vr == vm && (!acceptBounds || !vmIsTrailingZeros)) || lastRemovedDigit >= 5); . } else { 825,764 ( 6.13%) while (vp / 10 > vm / 10) { 94,845 ( 0.70%) lastRemovedDigit = (uint8_t) (vr % 10); 183,219 ( 1.36%) vr /= 10; . vp /= 10; . vm /= 10; 61,073 ( 0.45%) ++removed; . } 250,873 ( 1.86%) output = vr + (vr == vm || lastRemovedDigit >= 5); . } . . floating_decimal_32 fd; 60,677 ( 0.45%) fd.exponent = e10 + removed; . fd.mantissa = output; . return fd; . } . . static inline size_t to_chars_scientific(const floating_decimal_32 v, const bool sign, char* const result) { 77,522 ( 0.58%) size_t index = 0; 177,522 ( 1.32%) if (sign) { 33,717 ( 0.25%) result[index++] = '-'; . } . 4,262 ( 0.03%) uint32_t output = v.mantissa; . const uint32_t olength = decimalLength9(output); 41,006 ( 0.30%) uint32_t i = 0; 82,742 ( 0.61%) while (output >= 10000) { 535,633 ( 3.98%) const uint32_t c = output % 10000; 124,113 ( 0.92%) output /= 10000; 206,855 ( 1.54%) const uint32_t c0 = (c % 100) << 1; . const uint32_t c1 = (c / 100) << 1; 330,603 ( 2.46%) memcpy(result + index + olength - i - 1, DIGIT_TABLE + c0, 2); 165,484 ( 1.23%) memcpy(result + index + olength - i - 3, DIGIT_TABLE + c1, 2); 82,742 ( 0.61%) i += 4; . } 287,042 ( 2.13%) if (output >= 100) { 98,289 ( 0.73%) const uint32_t c = (output % 100) << 1; 98,289 ( 0.73%) output /= 100; 192,316 ( 1.43%) memcpy(result + index + olength - i - 1, DIGIT_TABLE + c, 2); 85,503 ( 0.63%) i += 2; . } 90,536 ( 0.67%) if (output >= 10) { 30,886 ( 0.23%) const uint32_t c = output << 1; 183,215 ( 1.36%) result[index + olength - i] = DIGIT_TABLE[c + 1]; 123,011 ( 0.91%) result[index] = DIGIT_TABLE[c]; . } else { 30,551 ( 0.23%) result[index] = (char) ('0' + output); . } . 2,631 ( 0.02%) if (olength > 1) { 47,369 ( 0.35%) result[index + 1] = '.'; 142,107 ( 1.06%) index += olength + 1; . } else { . ++index; . } . 100,000 ( 0.74%) result[index++] = 'e'; 50,000 ( 0.37%) int32_t exp = v.exponent + (int32_t) olength - 1; 150,000 ( 1.11%) if (exp < 0) { 69,339 ( 0.51%) result[index++] = '-'; 46,226 ( 0.34%) exp = -exp; . } . 100,000 ( 0.74%) if (exp >= 10) { 146,280 ( 1.09%) memcpy(result + index, DIGIT_TABLE + 2 * (uint32_t) exp, 2); 269,256 ( 2.00%) index += 2; . } else { 122,976 ( 0.91%) result[index++] = (char) ('0' + exp); . } . return index; . } . 100,000 ( 0.74%) size_t float_print(float f, char *out) { . const uint32_t bits = float_to_bits(f); . const bool sign = (bits >> 31) != 0; 100,000 ( 0.74%) const uint32_t ieeeMantissa = bits & ((1u << FLOAT_MANTISSA_BITS) - 1); 150,000 ( 1.11%) const uint32_t ieeeExponent = (bits >> FLOAT_MANTISSA_BITS) & ((1u << FLOAT_EXPONENT_BITS) - 1); . 100,000 ( 0.74%) if (ieeeExponent == 0xffu) { . if (ieeeMantissa != 0) { . memcpy(out, "nan", 3); . return 3; . } . if (sign) { . memcpy(out, "-inf", 4); . return 4; . } . memcpy(out, "inf", 3); . return 3; . } . 150,000 ( 1.11%) if ((bits << 1) == 0) { . if (sign) { . memcpy(out, "-0", 2); . return 2; . } . out[0] = '0'; . return 1; . } . . const floating_decimal_32 v = f2d(ieeeMantissa, ieeeExponent); . return to_chars_scientific(v, sign, out); 150,000 ( 1.11%) } -------------------------------------------------------------------------------- Ir -------------------------------------------------------------------------------- 13,465,612 (100.0%) events annotated --- Command finished with exit code: 0 ---

{"intent": "Inspect verifier's shortest-digit logic", "tool_calls": [{"tool": "agentgrep", "mode": "grep", "path": "verify/verify.c", "query": "significant", "regex": false, "max_regions": 20, "max_files": 1, "intent": "Find significant digit logic"}, {"tool": "agentgrep", "mode": "grep", "path": "verify/verify.c", "query": "shortest", "regex": false, "max_regions": 20, "max_files": 1, "intent": "Find shortest logic"}, {"tool": "read", "file_path": "verify/verify.c", "start_line": 1, "limit": 260, "intent": "Read verifier implementation"}]}

--- [1] agentgrep --- query: significant matches: 6 in 1 files verify.c symbols: no structural items detected - <file scope> - @ 6 // 4. shortest check: significant digits used == minimal round-tripping count - @ 38 // returns significant digit count, or -1 if malformed. - @ 68 // significant digits: all digits of int+frac, minus leading zeros - ... 3 more non-code matches omitted; narrow path/glob/type or use paths_only for full file list ... 3 more matches omitted (max_regions=20) --- [2] agentgrep --- query: shortest matches: 4 in 1 files verify.c symbols: no structural items detected - <file scope> - @ 6 // 4. shortest check: significant digits used == minimal round-tripping count - @ 81 // shortest by ROUND-TRIPPING at min_digits, so recompute leniently: - @ 136 // shortest - ... 1 more non-code matches omitted; narrow path/glob/type or use paths_only for full file list ... 1 more matches omitted (max_regions=20) --- [3] read --- 1 // verify.c — correctness gate for float-print. 2 // For each tested bit pattern: 3 // 1. run float_print, NUL-terminate, length check 4 // 2. format check (strict automaton) 5 // 3. round-trip check: strtof(out) bit-equals input 6 // 4. shortest check: significant digits used == minimal round-tripping count 7 // (minimal count computed independently with snprintf %.*g) 8 // Modes: default = stratified fast gate (~19M cases), --full = all 2^32. 9 // Multithreaded. Exit 0 = pass; prints first counterexample otherwise. 10 #include <stdint.h> 11 #include <stddef.h> 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <string.h> 15 #include <math.h> 16 #include <pthread.h> 17 #include <stdatomic.h> 18 19 size_t float_print(float f, char *out); 20 21 static atomic_ullong n_cases; 22 static atomic_int failed; 23 static pthread_mutex_t report_mu = PTHREAD_MUTEX_INITIALIZER; 24 25 // ---- independent minimal-digit oracle ---- 26 static int min_digits(float f) { 27 char buf[64]; 28 for (int p = 1; p <= 9; p++) { 29 snprintf(buf, sizeof(buf), "%.*g", p, (double)f); 30 if (strtof(buf, NULL) == f) return p; 31 } 32 return 9; 33 } 34 35 // ---- strict format automaton ---- 36 // -?D+(.D+)?(e[+-]?D+)? with: no leading zeros on integer part unless it is 37 // exactly "0"; fraction has no trailing zero; exponent has no leading zero; 38 // returns significant digit count, or -1 if malformed. 39 static int check_format(const char *s, size_t n) { 40 size_t i = 0; 41 if (i < n && s[i] == '-') i++; 42 // integer part 43 size_t int_start = i; 44 while (i < n && s[i] >= '0' && s[i] <= '9') i++; 45 size_t int_len = i - int_start; 46 if (int_len == 0) return -1; 47 if (int_len > 1 && s[int_start] == '0') return -1; // leading zero 48 size_t frac_len = 0; 49 if (i < n && s[i] == '.') { 50 i++; 51 size_t fs = i; 52 while (i < n && s[i] >= '0' && s[i] <= '9') i++; 53 frac_len = i - fs; 54 if (frac_len == 0) return -1; 55 if (s[i - 1] == '0') return -1; // trailing zero in fraction 56 } 57 if (i < n && (s[i] == 'e' || s[i] == 'E')) { 58 if (s[i] == 'E') return -1; // lowercase only 59 i++; 60 if (i < n && (s[i] == '+' || s[i] == '-')) i++; 61 size_t es = i; 62 while (i < n && s[i] >= '0' && s[i] <= '9') i++; 63 size_t elen = i - es; 64 if (elen == 0) return -1; 65 if (elen > 1 && s[es] == '0') return -1; // leading zero in exponent 66 } 67 if (i != n) return -1; 68 // significant digits: all digits of int+frac, minus leading zeros 69 // (a leading "0." contributes no significant digit). 70 int sig = 0; 71 int seen_nonzero = 0; 72 for (size_t k = int_start; k < n; k++) { 73 char c = s[k]; 74 if (c == 'e') break; 75 if (c < '0' || c > '9') continue; 76 if (c != '0') seen_nonzero = 1; 77 if (seen_nonzero) sig++; 78 } 79 // trailing zeros in the integer part are significant-or-not ambiguous 80 // (e.g. 100 for 1e2 uses 1 sig digit conceptually but 3 chars). We count 81 // shortest by ROUND-TRIPPING at min_digits, so recompute leniently: 82 // strip trailing zeros of integer-only outputs when no fraction present. 83 return sig ? sig : 1; // "0" -> 1 84 } 85 86 static int sig_digits_lenient(const char *s, size_t n) { 87 // significant digits ignoring trailing zeros when there is no '.' or 'e' 88 int has_dot = memchr(s, '.', n) != NULL; 89 int has_e = memchr(s, 'e', n) != NULL; 90 int sig = check_format(s, n); 91 if (sig < 0) return -1; 92 if (!has_dot && !has_e) { 93 // strip trailing zeros: 1200 -> 2 sig digits 94 size_t end = n; 95 while (end > 1 && s[end - 1] == '0') { end--; sig--; } 96 } 97 return sig; 98 } 99 100 static int check_one(uint32_t bits, char *msgbuf) { 101 float f; 102 memcpy(&f, &bits, 4); 103 char out[40]; 104 memset(out, 0x7F, sizeof(out)); 105 size_t n = float_print(f, out); 106 if (n == 0 || n > 31) { 107 sprintf(msgbuf, "bad length %zu", n); 108 return 0; 109 } 110 out[n] = '\0'; 111 // specials 112 if (isnan(f)) { 113 if (strcmp(out, "nan") != 0) { sprintf(msgbuf, "nan must print 'nan', got '%s'", out); return 0; } 114 return 1; 115 } 116 if (isinf(f)) { 117 const char *want = f < 0 ? "-inf" : "inf"; 118 if (strcmp(out, want) != 0) { sprintf(msgbuf, "inf mismatch: got '%s'", out); return 0; } 119 return 1; 120 } 121 // round trip 122 char *endp; 123 float back = strtof(out, &endp); 124 if (*endp != '\0') { sprintf(msgbuf, "strtof did not consume '%s'", out); return 0; } 125 uint32_t backbits; 126 memcpy(&backbits, &back, 4); 127 if (backbits != bits) { 128 sprintf(msgbuf, "round-trip failed: '%s' -> %08x != %08x", out, backbits, bits); 129 return 0; 130 } 131 if (f == 0.0f) return 1; // sign already verified by bit equality 132 // format 133 const char *body = out[0] == '-' ? out : out; 134 int sig = sig_digits_lenient(body, n); 135 if (sig < 0) { sprintf(msgbuf, "malformed output '%s'", out); return 0; } 136 // shortest 137 int md = min_digits(f); 138 if (sig > md) { 139 sprintf(msgbuf, "not shortest: '%s' uses %d sig digits, %d possible", out, sig, md); 140 return 0; 141 } 142 return 1; 143 } 144 145 static void fail_report(uint32_t bits, const char *msg) { 146 pthread_mutex_lock(&report_mu); 147 if (!atomic_exchange(&failed, 1)) { 148 float f; 149 memcpy(&f, &bits, 4); 150 fprintf(stderr, "MISMATCH on bits 0x%08x (%g): %s\n", bits, (double)f, msg); 151 } 152 pthread_mutex_unlock(&report_mu); 153 } 154 155 // ---- work scheduling ---- 156 typedef struct { uint64_t start, end, stride; } range_t; 157 #define MAX_RANGES 4096 158 static range_t ranges[MAX_RANGES]; 159 static int n_ranges; 160 static atomic_int next_range; 161 162 static void add_range(uint64_t start, uint64_t end, uint64_t stride) { 163 if (n_ranges >= MAX_RANGES) { fprintf(stderr, "range overflow\n"); exit(2); } 164 { 165 ranges[n_ranges++] = (range_t){start, end, stride}; 166 } 167 } 168 169 static void *worker(void *arg) { 170 (void)arg; 171 char msg[256]; 172 for (;;) { 173 int idx = atomic_fetch_add(&next_range, 1); 174 if (idx >= n_ranges) return NULL; 175 range_t r = ranges[idx]; 176 for (uint64_t v = r.start; v < r.end; v += r.stride) { 177 if (atomic_load_explicit(&failed, memory_order_relaxed)) return NULL; 178 if (!check_one((uint32_t)v, msg)) { 179 fail_report((uint32_t)v, msg); 180 return NULL; 181 } 182 atomic_fetch_add_explicit(&n_cases, 1, memory_order_relaxed); 183 } 184 } 185 } 186 187 static const uint32_t *extra_bits; 188 static size_t extra_n; 189 static atomic_ulong extra_next; 190 191 static void *extra_worker(void *arg) { 192 (void)arg; 193 char msg[256]; 194 for (;;) { 195 size_t i = atomic_fetch_add(&extra_next, 4096); 196 if (i >= extra_n) return NULL; 197 size_t end = i + 4096 < extra_n ? i + 4096 : extra_n; 198 for (; i < end; i++) { 199 if (atomic_load_explicit(&failed, memory_order_relaxed)) return NULL; 200 if (!check_one(extra_bits[i], msg)) { fail_report(extra_bits[i], msg); return NULL; } 201 atomic_fetch_add_explicit(&n_cases, 1, memory_order_relaxed); 202 } 203 } 204 } 205 206 static uint64_t rng_state = 0x6A636F6465ULL; 207 static uint64_t rng_next(void) { 208 uint64_t z = (rng_state += 0x9E3779B97F4A7C15ULL); 209 z = (z ^ (z >> 30)) * 0xBF58476D1CE4E5B9ULL; 210 z = (z ^ (z >> 27)) * 0x94D049BB133111EBULL; 211 return z ^ (z >> 31); 212 } 213 214 int main(int argc, char **argv) { 215 int full = 0; 216 uint64_t seed = 0x6A636F6465ULL; 217 for (int a = 1; a < argc; a++) { 218 if (strcmp(argv[a], "--full") == 0) full = 1; 219 else seed = strtoull(argv[a], NULL, 0); 220 } 221 rng_state = seed; 222 223 if (full) { 224 // all 2^32 patterns, split into 64 chunks 225 for (int k = 0; k < 64; k++) 226 add_range((uint64_t)k << 26, (uint64_t)(k + 1) << 26, 1); 227 } else { 228 // stratified fast gate: 229 // every exponent (0..255, both signs) x mantissa stride 512 (2^14 each) 230 for (int sgn = 0; sgn < 2; sgn++) 231 for (int ex = 0; ex < 256; ex++) { 232 uint64_t base = ((uint64_t)sgn << 31) | ((uint64_t)ex << 23); 233 add_range(base, base + (1u << 23), 512); 234 } 235 // all small integers as floats: 0..2^20 236 for (int k = 0; k < 8; k++) { 237 // convert integer to float bits: do it as its own range trick — 238 // handled below via explicit loop range marker (stride 0 unused); 239 (void)k; 240 } 241 // exact boundaries: first/last 4096 mantissas of every exponent 242 for (int sgn = 0; sgn < 2; sgn++) 243 for (int ex = 0; ex < 256; ex++) { 244 uint64_t base = ((uint64_t)sgn << 31) | ((uint64_t)ex << 23); 245 add_range(base, base + 4096, 1); 246 add_range(base + (1u << 23) - 4096, base + (1u << 23), 1); 247 } 248 } 249 250 int nthreads = 8; 251 pthread_t th[64]; 252 for (int t = 0; t < nthreads; t++) pthread_create(&th[t], NULL, worker, NULL); 253 for (int t = 0; t < nthreads; t++) pthread_join(th[t], NULL); 254 if (atomic_load(&failed)) return 1; 255 256 if (!full) { 257 // extra passes: small integers exactly + random patterns (threaded) 258 size_t n_extra = (1u << 20) + 1 + 2000000; 259 uint32_t *extra = malloc(n_extra * 4); 260 size_t k = 0; ... 17 more lines (use start_line=261 to continue) Completed: 3 succeeded, 0 failed

{"file_path": "verify/gen_corpus.py", "intent": "Inspect benchmark corpus distributions for targeted fast paths", "limit": 260, "start_line": 1}

1 #!/usr/bin/env python3 2 """gen_corpus.py — cost corpus for float-print: 200k float32 bit patterns. 3 Regimes: uniform bits 30%, round decimals 25%, small ints 15%, [0,1) 15%, 4 huge/tiny exponents 10%, denormals 5%. Output: raw little-endian uint32s. 5 Usage: gen_corpus.py SEED OUTFILE""" 6 import random, struct, sys 7 8 def f2b(f): 9 return struct.unpack('<I', struct.pack('<f', f))[0] 10 11 def main(): 12 seed, out = int(sys.argv[1]), sys.argv[2] 13 rng = random.Random(seed) 14 N = 50000 15 vals = [] 16 for _ in range(int(N*0.30)): 17 b = rng.getrandbits(32) 18 # avoid nan/inf dominating: re-roll exponent 255 19 while (b >> 23) & 0xFF == 0xFF: 20 b = rng.getrandbits(32) 21 vals.append(b) 22 for _ in range(int(N*0.25)): 23 mant = rng.randrange(1, 10**rng.randrange(1, 7)) 24 exp = rng.randrange(-6, 7) 25 v = float(mant) * (10.0 ** exp) 26 vals.append(f2b(struct.unpack('<f', struct.pack('<f', v))[0])) 27 for _ in range(int(N*0.15)): 28 vals.append(f2b(float(rng.randrange(0, 1 << 20)))) 29 for _ in range(int(N*0.15)): 30 vals.append(f2b(struct.unpack('<f', struct.pack('<f', rng.random()))[0])) 31 for _ in range(int(N*0.10)): 32 ex = rng.choice(list(range(1, 20)) + list(range(230, 255))) 33 b = (rng.getrandbits(1) << 31) | (ex << 23) | rng.getrandbits(23) 34 vals.append(b) 35 while len(vals) < N: 36 vals.append((rng.getrandbits(1) << 31) | rng.getrandbits(23)) # denormal 37 rng.shuffle(vals) 38 with open(out, 'wb') as f: 39 for v in vals: 40 f.write(struct.pack('<I', v)) 41 print(f"corpus: {len(vals)} floats, seed {seed}") 42 43 if __name__ == '__main__': 44 main()

{"intent": "Add exact-integer fast path and trim formatting overhead", "patch_text": "*** Begin Patch\n*** Update File: submission/solve.c\n@@\n static const char DIGIT_TABLE[200] = {\n@@\n };\n+\n+static inline void copy_two_digits(char *dst, uint32_t idx) {\n+ dst[0] = DIGIT_TABLE[idx];\n+ dst[1] = DIGIT_TABLE[idx + 1];\n+}\n@@\n static inline floating_decimal_32 f2d(const uint32_t ieeeMantissa, const uint32_t ieeeExponent) {\n@@\n return fd;\n }\n+\n+static inline size_t u32_to_decimal(uint32_t output, char *result) {\n+ const uint32_t olength = output >= 1000000000u ? 10u : decimalLength9(output);\n+ uint32_t i = 0;\n+ while (output >= 10000) {\n+ const uint32_t c = output % 10000;\n+ output /= 10000;\n+ const uint32_t c0 = (c % 100) << 1;\n+ const uint32_t c1 = (c / 100) << 1;\n+ copy_two_digits(result + olength - i - 1, c0);\n+ copy_two_digits(result + olength - i - 3, c1);\n+ i += 4;\n+ }\n+ if (output >= 100) {\n+ const uint32_t c = (output % 100) << 1;\n+ output /= 100;\n+ copy_two_digits(result + olength - i - 1, c);\n+ i += 2;\n+ }\n+ if (output >= 10) {\n+ const uint32_t c = output << 1;\n+ result[olength - i - 2] = DIGIT_TABLE[c];\n+ result[olength - i - 1] = DIGIT_TABLE[c + 1];\n+ } else {\n+ result[olength - i - 1] = (char) ('0' + output);\n+ }\n+ return olength;\n+}\n@@\n static inline size_t to_chars_scientific(const floating_decimal_32 v, const bool sign, char* const result) {\n@@\n while (output >= 10000) {\n const uint32_t c = output % 10000;\n output /= 10000;\n const uint32_t c0 = (c % 100) << 1;\n const uint32_t c1 = (c / 100) << 1;\n- memcpy(result + index + olength - i - 1, DIGIT_TABLE + c0, 2);\n- memcpy(result + index + olength - i - 3, DIGIT_TABLE + c1, 2);\n+ copy_two_digits(result + index + olength - i - 1, c0);\n+ copy_two_digits(result + index + olength - i - 3, c1);\n i += 4;\n }\n if (output >= 100) {\n const uint32_t c = (output % 100) << 1;\n output /= 100;\n- memcpy(result + index + olength - i - 1, DIGIT_TABLE + c, 2);\n+ copy_two_digits(result + index + olength - i - 1, c);\n i += 2;\n }\n@@\n }\n \n if (exp >= 10) {\n- memcpy(result + index, DIGIT_TABLE + 2 * (uint32_t) exp, 2);\n+ copy_two_digits(result + index, 2 * (uint32_t) exp);\n index += 2;\n } else {\n result[index++] = (char) ('0' + exp);\n }\n return index;\n }\n+\n+static inline bool try_format_u32_integer(const bool sign, const uint32_t ieeeMantissa, const uint32_t ieeeExponent, char *out, size_t *n_out) {\n+ if (ieeeExponent < FLOAT_BIAS || ieeeExponent > FLOAT_BIAS + 31) {\n+ return false;\n+ }\n+\n+ const uint32_t e = ieeeExponent - FLOAT_BIAS;\n+ const uint32_t m = (1u << FLOAT_MANTISSA_BITS) | ieeeMantissa;\n+ uint32_t value;\n+ if (e >= FLOAT_MANTISSA_BITS) {\n+ value = m << (e - FLOAT_MANTISSA_BITS);\n+ } else {\n+ const uint32_t shift = FLOAT_MANTISSA_BITS - e;\n+ if ((m & ((1u << shift) - 1u)) != 0) {\n+ return false;\n+ }\n+ value = m >> shift;\n+ }\n+\n+ size_t index = 0;\n+ if (sign) {\n+ out[index++] = '-';\n+ }\n+ index += u32_to_decimal(value, out + index);\n+ *n_out = index;\n+ return true;\n+}\n \n size_t float_print(float f, char *out) {\n@@\n if ((bits << 1) == 0) {\n if (sign) {\n memcpy(out, \"-0\", 2);\n return 2;\n@@\n out[0] = '0';\n return 1;\n }\n+\n+ size_t n;\n+ if (try_format_u32_integer(sign, ieeeMantissa, ieeeExponent, out, &n)) {\n+ return n;\n+ }\n \n const floating_decimal_32 v = f2d(ieeeMantissa, ieeeExponent);\n return to_chars_scientific(v, sign, out);\n }\n*** End Patch"}

✓ submission/solve.c: modified (9 hunks) 60+ static inline void copy_two_digits(char *dst, uint32_t idx) { 61+ dst[0] = DIGIT_TABLE[idx]; 62+ dst[1] = DIGIT_TABLE[idx + 1]; 63+ } 251+ static inline size_t u32_to_decimal(uint32_t output, char *result) { 252+ const uint32_t olength = output >= 1000000000u ? 10u : decimalLength9(output); 253+ uint32_t i = 0; 254+ while (output >= 10000) { 255+ const uint32_t c = output % 10000; 256+ output /= 10000; 257+ const uint32_t c0 = (c % 100) << 1; 258+ const uint32_t c1 = (c / 100) << 1; 259+ copy_two_digits(result + olength - i - 1, c0); 260+ copy_two_digits(result + olength - i - 3, c1); 261+ i += 4; 262+ } 263+ if (output >= 100) { 264+ const uint32_t c = (output % 100) << 1; 265+ output /= 100; 266+ copy_two_digits(result + olength - i - 1, c); 267+ i += 2; 268+ } 269+ if (output >= 10) { 270+ const uint32_t c = output << 1; 271+ result[olength - i - 2] = DIGIT_TABLE[c]; 272+ result[olength - i - 1] = DIGIT_TABLE[c + 1]; 273+ } else { 274+ result[olength - i - 1] = (char) ('0' + output); 275+ } 276+ return olength; ... (diff truncated)

{"command": "./grade", "intent": "Grade integer-fast-path implementation", "notify": false, "run_in_background": false, "timeout": 1200000, "wake": false}

MISMATCH on bits 0x43000000 (128): strtof did not consume '12' grade: FAIL (verification) --- Command finished with exit code: 1 --- Exit code: 1

{"intent": "Fix integer decimal formatting helper", "patch_text": "*** Begin Patch\n*** Update File: submission/solve.c\n@@\n static inline size_t u32_to_decimal(uint32_t output, char *result) {\n const uint32_t olength = output >= 1000000000u ? 10u : decimalLength9(output);\n- uint32_t i = 0;\n- while (output >= 10000) {\n- const uint32_t c = output % 10000;\n- output /= 10000;\n- const uint32_t c0 = (c % 100) << 1;\n- const uint32_t c1 = (c / 100) << 1;\n- copy_two_digits(result + olength - i - 1, c0);\n- copy_two_digits(result + olength - i - 3, c1);\n- i += 4;\n- }\n- if (output >= 100) {\n- const uint32_t c = (output % 100) << 1;\n- output /= 100;\n- copy_two_digits(result + olength - i - 1, c);\n- i += 2;\n- }\n- if (output >= 10) {\n- const uint32_t c = output << 1;\n- result[olength - i - 2] = DIGIT_TABLE[c];\n- result[olength - i - 1] = DIGIT_TABLE[c + 1];\n- } else {\n- result[olength - i - 1] = (char) ('0' + output);\n- }\n+ char *p = result + olength;\n+ while (output >= 100) {\n+ const uint32_t c = (output % 100) << 1;\n+ output /= 100;\n+ p -= 2;\n+ copy_two_digits(p, c);\n+ }\n+ if (output >= 10) {\n+ const uint32_t c = output << 1;\n+ p -= 2;\n+ copy_two_digits(p, c);\n+ } else {\n+ *--p = (char) ('0' + output);\n+ }\n return olength;\n }\n*** End Patch"}

✓ submission/solve.c: modified (1 hunks) 253- uint32_t i = 0; 254- while (output >= 10000) { 255- const uint32_t c = output % 10000; 256- output /= 10000; 257- const uint32_t c0 = (c % 100) << 1; 258- const uint32_t c1 = (c / 100) << 1; 259- copy_two_digits(result + olength - i - 1, c0); 260- copy_two_digits(result + olength - i - 3, c1); 261- i += 4; 262- } 263- if (output >= 100) { 253+ char *p = result + olength; 254+ while (output >= 100) { 266- copy_two_digits(result + olength - i - 1, c); 267- i += 2; 257+ p -= 2; 258+ copy_two_digits(p, c); 271- result[olength - i - 2] = DIGIT_TABLE[c]; 272- result[olength - i - 1] = DIGIT_TABLE[c + 1]; 262+ p -= 2; 263+ copy_two_digits(p, c); 274- result[olength - i - 1] = (char) ('0' + output); 265+ *--p = (char) ('0' + output);

{"command": "./grade", "intent": "Regrade after fixing integer decimal formatting", "notify": false, "run_in_background": false, "timeout": 1200000, "wake": false}

MISMATCH on bits 0x4c000400 (3.35585e+07): not shortest: '33558528' uses 8 sig digits, 7 possible grade: FAIL (verification) --- Command finished with exit code: 1 --- Exit code: 1

{"intent": "Restrict integer fast path to safe consecutive-integer range", "patch_text": "*** Begin Patch\n*** Update File: submission/solve.c\n@@\n if (e >= FLOAT_MANTISSA_BITS) {\n value = m << (e - FLOAT_MANTISSA_BITS);\n } else {\n const uint32_t shift = FLOAT_MANTISSA_BITS - e;\n if ((m & ((1u << shift) - 1u)) != 0) {\n@@\n }\n value = m >> shift;\n }\n+\n+ if (value >= (1u << 24)) {\n+ return false;\n+ }\n \n size_t index = 0;\n*** End Patch"}

✓ submission/solve.c: modified (2 hunks) 343+ if (value >= (1u << 24)) { 344+ return false; 345+ }

{"command": "./grade", "intent": "Regrade after restricting integer fast path to safe range", "notify": false, "run_in_background": false, "timeout": 1200000, "wake": false}

build 0.9s verify 7.3s PASS measure 7.0s 59,634,664 instructions (given: 4,481,392,741) SCORE +6.2317 (75.147x) --- Command finished with exit code: 0 ---

{"command": "callgrind_annotate .build/callgrind.runner.out | sed -n '1,260p'", "intent": "Profile updated implementation for final low-risk improvements", "notify": false, "run_in_background": false, "timeout": 120000, "wake": false}

-------------------------------------------------------------------------------- Profile data file '.build/callgrind.runner.out' (creator: callgrind-3.25.1) -------------------------------------------------------------------------------- I1 cache: D1 cache: LL cache: Timerange: Basic block 0 - 1388208 Trigger: Program termination Profiled target: /tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/runner /tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/corpus_28792.bin (PID 419, part 1) Events recorded: Ir Events shown: Ir Event sort order: Ir Thresholds: 99 Include dirs: User annotated: Auto-annotation: on -------------------------------------------------------------------------------- Ir -------------------------------------------------------------------------------- 11,660,488 (100.0%) PROGRAM TOTALS -------------------------------------------------------------------------------- Ir file:function -------------------------------------------------------------------------------- 11,660,488 (100.0%) submission/solve.c:float_print [/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/runner] -------------------------------------------------------------------------------- -- Auto-annotated source: submission/solve.c -------------------------------------------------------------------------------- Ir -- line 53 ---------------------------------------- . '5','0','5','1','5','2','5','3','5','4','5','5','5','6','5','7','5','8','5','9', . '6','0','6','1','6','2','6','3','6','4','6','5','6','6','6','7','6','8','6','9', . '7','0','7','1','7','2','7','3','7','4','7','5','7','6','7','7','7','8','7','9', . '8','0','8','1','8','2','8','3','8','4','8','5','8','6','8','7','8','8','8','9', . '9','0','9','1','9','2','9','3','9','4','9','5','9','6','9','7','9','8','9','9' . }; . . static inline void copy_two_digits(char *dst, uint32_t idx) { 424,193 ( 3.64%) dst[0] = DIGIT_TABLE[idx]; 258,276 ( 2.21%) dst[1] = DIGIT_TABLE[idx + 1]; . } . . typedef struct { . uint32_t mantissa; . int32_t exponent; . } floating_decimal_32; . . static inline uint32_t float_to_bits(float f) { . uint32_t bits; 50,000 ( 0.43%) memcpy(&bits, &f, sizeof(bits)); . return bits; . } . . static inline uint32_t decimalLength9(uint32_t v) { 76,038 ( 0.65%) if (v >= 100000000) return 9; 147,176 ( 1.26%) if (v >= 10000000) return 8; 116,420 ( 1.00%) if (v >= 1000000) return 7; 51,232 ( 0.44%) if (v >= 100000) return 6; 26,512 ( 0.23%) if (v >= 10000) return 5; 23,705 ( 0.20%) if (v >= 1000) return 4; 17,914 ( 0.15%) if (v >= 100) return 3; 12,324 ( 0.11%) if (v >= 10) return 2; . return 1; . } . . static inline uint32_t log10Pow2(const int32_t e) { 44,200 ( 0.38%) return (uint32_t) ((((uint32_t) e) * 78913u) >> 18); . } . . static inline uint32_t log10Pow5(const int32_t e) { 72,738 ( 0.62%) return (uint32_t) ((((uint32_t) e) * 732923u) >> 20); . } . . static inline int32_t pow5bits(const int32_t e) { 82,840 ( 0.71%) return (int32_t) ((((uint32_t) e) * 1217359u) >> 19) + 1; . } . . static inline uint32_t pow5factor_32(uint32_t value) { 3,134 ( 0.03%) uint32_t count = 0; . for (;;) { 40,238 ( 0.35%) const uint32_t q = value / 5; 33,687 ( 0.29%) if (value != q * 5) { . break; . } . value = q; 13,192 ( 0.11%) ++count; . } . return count; . } . . static inline bool multipleOfPowerOf5_32(const uint32_t value, const uint32_t p) { 1,247 ( 0.01%) return pow5factor_32(value) >= p; . } . . static inline bool multipleOfPowerOf2_32(const uint32_t value, const uint32_t p) { 31,322 ( 0.27%) return (value & ((1u << p) - 1)) == 0; . } . . static inline uint32_t mulShift32(const uint32_t m, const uint64_t factor, const int32_t shift) { . const uint32_t factorLo = (uint32_t) factor; 76,716 ( 0.66%) const uint32_t factorHi = (uint32_t) (factor >> 32); 272,080 ( 2.33%) const uint64_t bits0 = (uint64_t) m * factorLo; 168,566 ( 1.45%) const uint64_t bits1 = (uint64_t) m * factorHi; 239,336 ( 2.05%) const uint64_t sum = (bits0 >> 32) + bits1; 299,662 ( 2.57%) return (uint32_t) (sum >> (shift - 32)); . } . . static inline uint32_t mulPow5InvDivPow2(const uint32_t m, const uint32_t q, const int32_t j) { 23,768 ( 0.20%) return mulShift32(m, FLOAT_POW5_INV_SPLIT[q], j); . } . . static inline uint32_t mulPow5divPow2(const uint32_t m, const uint32_t i, const int32_t j) { 81,650 ( 0.70%) return mulShift32(m, FLOAT_POW5_SPLIT[i], j); . } . . static inline floating_decimal_32 f2d(const uint32_t ieeeMantissa, const uint32_t ieeeExponent) { . int32_t e2; . uint32_t m2; 64,522 ( 0.55%) if (ieeeExponent == 0) { . e2 = 1 - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; . m2 = ieeeMantissa; . } else { . e2 = (int32_t) ieeeExponent - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; . m2 = (1u << FLOAT_MANTISSA_BITS) | ieeeMantissa; . } 78,248 ( 0.67%) const bool even = (m2 & 1) == 0; . const bool acceptBounds = even; . 110,992 ( 0.95%) const uint32_t mv = 4 * m2; 70,592 ( 0.61%) const uint32_t mp = 4 * m2 + 2; 284,920 ( 2.44%) const uint32_t mmShift = ieeeMantissa != 0 || ieeeExponent <= 1; 164,152 ( 1.41%) const uint32_t mm = 4 * m2 - 1 - mmShift; . . uint32_t vr, vp, vm; . int32_t e10; 1,467 ( 0.01%) bool vmIsTrailingZeros = false; . bool vrIsTrailingZeros = false; 37,848 ( 0.32%) uint8_t lastRemovedDigit = 0; . 105,888 ( 0.91%) if (e2 >= 0) { . const uint32_t q = log10Pow2(e2); 11,050 ( 0.09%) e10 = (int32_t) q; . const int32_t k = FLOAT_POW5_INV_BITCOUNT + pow5bits((int32_t) q) - 1; 33,150 ( 0.28%) const int32_t i = -e2 + (int32_t) q + k; . vr = mulPow5InvDivPow2(mv, q, i); . vp = mulPow5InvDivPow2(mp, q, i); . vm = mulPow5InvDivPow2(mm, q, i); 127,035 ( 1.09%) if (q != 0 && (vp - 1) / 10 <= vm / 10) { 5,004 ( 0.04%) const int32_t l = FLOAT_POW5_INV_BITCOUNT + pow5bits((int32_t) (q - 1)) - 1; 10,008 ( 0.09%) lastRemovedDigit = (uint8_t) (mulPow5InvDivPow2(mv, q - 1, -e2 + (int32_t) q - 1 + l) % 10); . } 22,888 ( 0.20%) if (q <= 9) { 8,254 ( 0.07%) if (mv % 5 == 0) { 1,092 ( 0.01%) vrIsTrailingZeros = multipleOfPowerOf5_32(mv, q); 7,806 ( 0.07%) } else if (acceptBounds) { . vmIsTrailingZeros = multipleOfPowerOf5_32(mm, q); . } else { 3,741 ( 0.03%) vp -= multipleOfPowerOf5_32(mp, q); . } . } . } else { . const uint32_t q = log10Pow5(-e2); 48,492 ( 0.42%) e10 = (int32_t) q + e2; 121,230 ( 1.04%) const int32_t i = -e2 - (int32_t) q; . const int32_t k = pow5bits(i) - FLOAT_POW5_BITCOUNT; 24,246 ( 0.21%) int32_t j = (int32_t) q - k; . vr = mulPow5divPow2(mv, (uint32_t) i, j); . vp = mulPow5divPow2(mp, (uint32_t) i, j); . vm = mulPow5divPow2(mm, (uint32_t) i, j); 320,571 ( 2.75%) if (q != 0 && (vp - 1) / 10 <= vm / 10) { 17,824 ( 0.15%) j = (int32_t) q - 1 - (pow5bits(i + 1) - FLOAT_POW5_BITCOUNT); 26,736 ( 0.23%) lastRemovedDigit = (uint8_t) (mulPow5divPow2(mv, (uint32_t) (i + 1), j) % 10); . } 53,194 ( 0.46%) if (q <= 1) { . vrIsTrailingZeros = true; 603 ( 0.01%) if (acceptBounds) { . vmIsTrailingZeros = mmShift == 1; . } else { . --vp; . } 79,791 ( 0.68%) } else if (q < 31) { 16,036 ( 0.14%) vrIsTrailingZeros = multipleOfPowerOf2_32(mv, q - 1); . } . } . 36,035 ( 0.31%) int32_t removed = 0; . uint32_t output; 50,757 ( 0.44%) if (vmIsTrailingZeros || vrIsTrailingZeros) { 71,747 ( 0.62%) while (vp / 10 > vm / 10) { 39,168 ( 0.34%) vmIsTrailingZeros &= vm % 10 == 0; 13,056 ( 0.11%) vrIsTrailingZeros &= lastRemovedDigit == 0; 56,280 ( 0.48%) lastRemovedDigit = (uint8_t) (vr % 10); 6,528 ( 0.06%) vr /= 10; . vp /= 10; . vm /= 10; 13,056 ( 0.11%) ++removed; . } 3,528 ( 0.03%) if (vmIsTrailingZeros) { 1,023 ( 0.01%) while (vm % 10 == 0) { 596 ( 0.01%) vrIsTrailingZeros &= lastRemovedDigit == 0; 2,621 ( 0.02%) lastRemovedDigit = (uint8_t) (vr % 10); 298 ( 0.00%) vr /= 10; . vp /= 10; 894 ( 0.01%) vm /= 10; 1,192 ( 0.01%) ++removed; . } . } 4,038 ( 0.03%) if (vrIsTrailingZeros && lastRemovedDigit == 5 && (vr & 1u) == 0) { . lastRemovedDigit = 4; . } 11,736 ( 0.10%) output = vr + ((vr == vm && (!acceptBounds || !vmIsTrailingZeros)) || lastRemovedDigit >= 5); . } else { 926,661 ( 7.95%) while (vp / 10 > vm / 10) { 95,163 ( 0.82%) lastRemovedDigit = (uint8_t) (vr % 10); 184,725 ( 1.58%) vr /= 10; . vp /= 10; . vm /= 10; 61,575 ( 0.53%) ++removed; . } 287,664 ( 2.47%) output = vr + (vr == vm || lastRemovedDigit >= 5); . } . . floating_decimal_32 fd; 36,377 ( 0.31%) fd.exponent = e10 + removed; . fd.mantissa = output; . return fd; . } . . static inline size_t u32_to_decimal(uint32_t output, char *result) { . const uint32_t olength = output >= 1000000000u ? 10u : decimalLength9(output); 22,185 ( 0.19%) char *p = result + olength; 74,223 ( 0.64%) while (output >= 100) { 140,964 ( 1.21%) ... [1105 characters truncated for page size]

{"command": "git status --short", "intent": "Check repository status before final validation and possible commit", "notify": false, "run_in_background": false, "timeout": 120000, "wake": false}

fatal: not a git repository (or any of the parent directories): .git --- Command finished with exit code: 128 --- Exit code: 128

{"command": "./grade --full", "intent": "Run full exhaustive gate on best implementation", "notify": true, "run_in_background": true, "timeout": 7200000, "wake": true}

Command started in background. Task ID: 828775jv6p Name: Run full exhaustive gate on Output file: /tmp/jcode-bg-tasks/828775jv6p.output Status file: /tmp/jcode-bg-tasks/828775jv6p.status.json The agent will be woken when the task completes. To wait for completion/checkpoints: use the `bg` tool with action="wait" and task_id="828775jv6p" To check progress immediately: use the `bg` tool with action="status" and task_id="828775jv6p" To see output: use the `read` tool on the output file, or `bg` with action="output"

{"action": "wait", "dry_run": false, "graceful_timeout_ms": null, "include_output_preview": true, "intent": "Wait for full gate completion", "latest": false, "lines": null, "max_age_hours": null, "max_wait_seconds": 600, "notify": true, "return_on_progress": true, "session_only": true, "status_filter": null, "tail_lines": 80, "task_id": "828775jv6p", "task_ids": null, "wait_mode": "any", "wake": true}

Background task finished. Task: 828775jv6p Name: Run full exhaustive gate on Tool: bash Status: failed Session: session_shrimp_1784428611899_42090596090735a0 Started: 2026-07-19T02:40:28.775495821+00:00 Completed: 2026-07-19T02:50:28.786478546+00:00 Duration: 600.01s Exit code: 124 Notify: true Wake: true Error: Command timed out after 600000ms (600.0s) Recent events: - Failed · 2026-07-19T02:50:28.786499807+00:00 · Command timed out after 600000ms (600.0s) Output preview: ```text --- Command timed out after 600000ms (600.0s) --- ```

{"command": "./grade --full", "intent": "Rerun full exhaustive gate with a longer timeout", "notify": false, "run_in_background": false, "timeout": 1800000, "wake": false}

Command exceeded the foreground timeout after 600.0s and is continuing in background. Task ID: 433318d9fx Name: Rerun full exhaustive gate w Foreground time used: 600.1s Output file: /tmp/jcode-bg-tasks/433318d9fx.output Status file: /tmp/jcode-bg-tasks/433318d9fx.status.json The command is still running; do not rerun it unless you intentionally want a second copy. Use `bg` with action="wait" and task_id="433318d9fx" to wait for completion or the next progress checkpoint. Use `bg` with action="output" and task_id="433318d9fx" to inspect output.

{"action": "wait", "dry_run": false, "graceful_timeout_ms": null, "include_output_preview": true, "intent": "Wait for long full gate run to finish", "latest": false, "lines": null, "max_age_hours": null, "max_wait_seconds": 1200, "notify": true, "return_on_progress": true, "session_only": true, "status_filter": null, "tail_lines": 120, "task_id": "433318d9fx", "task_ids": null, "wait_mode": "any", "wake": true}

No terminal event before max wait of 1200s. Check again with `bg action="wait" task_id="433318d9fx"` or inspect status/output. Task: 433318d9fx Name: Rerun full exhaustive gate w Tool: bash Status: running Session: session_shrimp_1784428611899_42090596090735a0 Started: 2026-07-19T02:50:33.318888443+00:00 Notify: false Wake: false

{"action": "wait", "dry_run": false, "graceful_timeout_ms": null, "include_output_preview": true, "intent": "Continue waiting for exhaustive gate result", "latest": false, "lines": null, "max_age_hours": null, "max_wait_seconds": 1800, "notify": true, "return_on_progress": true, "session_only": true, "status_filter": null, "tail_lines": 120, "task_id": "433318d9fx", "task_ids": null, "wait_mode": "any", "wake": true}

Background task finished. Task: 433318d9fx Name: Rerun full exhaustive gate w Tool: bash Status: completed Session: session_shrimp_1784428611899_42090596090735a0 Started: 2026-07-19T02:50:33.318888443+00:00 Completed: 2026-07-19T03:23:21.258274720+00:00 Duration: 1967.94s Exit code: 0 Notify: false Wake: false Recent events: - Completed · 2026-07-19T03:23:21.258341155+00:00 Output preview: ```text build 0.9s verify 1959.0s PASS (FULL gate) measure 6.9s 59,672,118 instructions (given: 4,487,121,571) SCORE +6.2326 (75.196x) --- Command finished with exit code: 0 --- ```

{"command": "python3 - <<'PY'\nimport json\nbest=None\nfor line in open('scores.jsonl'):\n rec=json.loads(line)\n if best is None or rec['score']>best['score']:\n best=rec\nprint(best)\nPY", "intent": "Extract best recorded score from scores.jsonl", "notify": false, "run_in_background": false, "timeout": 120000, "wake": false}

{'ts': '2026-07-19T03:23:20Z', 'seed': 29433, 'cost': 59672118, 'given_cost': 4487121571, 'score': 6.2326, 'full_gate': True} --- Command finished with exit code: 0 ---

{"goals": [{"end_to_end_ownership": 100, "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline.", "group": "float-print optimization", "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session.", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100}], "intent": "Mark float-print benchmark work complete", "todos": [{"completion_confidence": 100, "confidence": 100, "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "group": "float-print optimization", "id": "read-spec-code", "priority": "high", "status": "completed"}, {"completion_confidence": 97, "confidence": 97, "content": "Profile and optimize submission implementation with repeated grade runs", "group": "float-print optimization", "id": "optimize-grade", "priority": "high", "status": "completed"}, {"completion_confidence": 100, "confidence": 100, "content": "Validate final implementation, record best score, and summarize changes", "group": "float-print optimization", "id": "finalize-report", "priority": "medium", "status": "completed"}]}

[ { "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "status": "completed", "priority": "high", "id": "read-spec-code", "group": "float-print optimization", "confidence": 100, "completion_confidence": 100, "confidence_history": [ 95, 100 ] }, { "content": "Profile and optimize submission implementation with repeated grade runs", "status": "completed", "priority": "high", "id": "optimize-grade", "group": "float-print optimization", "confidence": 97, "completion_confidence": 97, "confidence_history": [ 85, 97 ] }, { "content": "Validate final implementation, record best score, and summarize changes", "status": "completed", "priority": "medium", "id": "finalize-report", "group": "float-print optimization", "confidence": 100, "completion_confidence": 100, "confidence_history": [ 80, 100 ] } ] Goals: [ { "group": "float-print optimization", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100, "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session.", "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline.", "end_to_end_ownership": 100 } ]

{"goals": [{"end_to_end_ownership": null, "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline. Before finalizing, collect at least one exhaustive correctness result and multiple independent seeded grade results.", "group": "float-print optimization", "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session, backed by one full 2^32-bit gate and additional independent seeded rechecks.", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100}], "intent": "Reopen validation with stronger independent evidence", "todos": [{"completion_confidence": 100, "confidence": 100, "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "group": "float-print optimization", "id": "read-spec-code", "priority": "high", "status": "completed"}, {"completion_confidence": 97, "confidence": 97, "content": "Profile and optimize submission implementation with repeated grade runs", "group": "float-print optimization", "id": "optimize-grade", "priority": "high", "status": "completed"}, {"completion_confidence": null, "confidence": 95, "content": "Recheck final implementation with independent evidence, record best score, and summarize readiness", "group": "float-print optimization", "id": "finalize-report", "priority": "high", "status": "in_progress"}]}

[ { "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "status": "completed", "priority": "high", "id": "read-spec-code", "group": "float-print optimization", "confidence": 100, "completion_confidence": 100, "confidence_history": [ 95, 100 ] }, { "content": "Profile and optimize submission implementation with repeated grade runs", "status": "completed", "priority": "high", "id": "optimize-grade", "group": "float-print optimization", "confidence": 97, "completion_confidence": 97, "confidence_history": [ 85, 97 ] }, { "content": "Recheck final implementation with independent evidence, record best score, and summarize readiness", "status": "in_progress", "priority": "high", "id": "finalize-report", "group": "float-print optimization", "confidence": 95, "confidence_history": [ 80, 100, 95 ] } ] Goals: [ { "group": "float-print optimization", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100, "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session, backed by one full 2^32-bit gate and additional independent seeded rechecks.", "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline. Before finalizing, collect at least one exhaustive correctness result and multiple independent seeded grade results." } ]

{"command": "set -euo pipefail\nscratch=\"$JCODE_SCRATCH_DIR/float-print-recheck\"\nmkdir -p \"$scratch\"\ncat > \"$scratch/check.c\" <<'EOF'\n#include <stdint.h>\n#include <stdio.h>\n#include <string.h>\n#include <stdlib.h>\nsize_t float_print(float f, char *out);\nstatic float bits_to_float(uint32_t bits) {\n float f;\n memcpy(&f, &bits, 4);\n return f;\n}\nint main(void) {\n static const uint32_t bits_list[] = {\n 0x00000000u, 0x80000000u, 0x7f800000u, 0xff800000u, 0x7fc00001u,\n 0x3f800000u, 0x3f000000u, 0x3eaaaaabu, 0x43000000u, 0x4c000400u,\n 0x007fffffu, 0x00800000u, 0x7f7fffffu, 0x00000001u, 0x80000001u,\n 0x3f7fffffu, 0x3f800001u, 0x41200000u, 0x4b7fffffu, 0x4b800000u\n };\n for (size_t i = 0; i < sizeof(bits_list) / sizeof(bits_list[0]); ++i) {\n uint32_t bits = bits_list[i];\n float f = bits_to_float(bits);\n char out[64] = {0};\n size_t n = float_print(f, out);\n out[n] = '\\0';\n printf(\"0x%08x -> %s\\n\", bits, out);\n }\n return 0;\n}\nEOF\ncc -O2 -std=c17 -I submission submission/solve.c \"$scratch/check.c\" -o \"$scratch/check\" -lm\nprintf '=== targeted edge-case outputs ===\\n'\n\"$scratch/check\"\nprintf '\\n=== grade seed 101 ===\\n'\n./grade --seed 101\nprintf '\\n=== grade seed 202 ===\\n'\n./grade --seed 202\nprintf '\\n=== grade seed 303 ===\\n'\n./grade --seed 303\n", "intent": "Run independent seeded grades and targeted edge-case output checks", "notify": false, "run_in_background": false, "timeout": 1800000, "wake": false}

=== targeted edge-case outputs === 0x00000000 -> 0 0x80000000 -> -0 0x7f800000 -> inf 0xff800000 -> -inf 0x7fc00001 -> nan 0x3f800000 -> 1 0x3f000000 -> 5e-1 0x3eaaaaab -> 3.3333334e-1 0x43000000 -> 128 0x4c000400 -> 3.355853e7 0x007fffff -> 1.1754942e-38 0x00800000 -> 1.1754944e-38 0x7f7fffff -> 3.4028235e38 0x00000001 -> 1e-45 0x80000001 -> -1e-45 0x3f7fffff -> 9.9999994e-1 0x3f800001 -> 1.0000001e0 0x41200000 -> 10 0x4b7fffff -> 16777215 0x4b800000 -> 1.6777216e7 === grade seed 101 === Traceback (most recent call last): File "/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/./grade", line 5, in <module> main(os.path.dirname(os.path.abspath(__file__)), "float_print") ~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/../../harness/grade.py", line 84, in main cost = measure("runner", fn) File "/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/../../harness/grade.py", line 70, in measure sh(["valgrind", "--tool=callgrind", f"--toggle-collect={func}", ~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ "--collect-atstart=no", "--dump-line=no", ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ f"--callgrind-out-file={cg}", os.path.join(BUILD, binary), corpus]) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/../../harness/grade.py", line 16, in sh return subprocess.run(cmd, check=True, capture_output=True, text=True, **kw) ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/lib/python3.14/subprocess.py", line 578, in run raise CalledProcessError(retcode, process.args, output=stdout, stderr=stderr) subprocess.CalledProcessError: Command '['valgrind', '--tool=callgrind', '--toggle-collect=float_print', '--collect-atstart=no', '--dump-line=no', '--callgrind-out-file=/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/callgrind.runner.out', '/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/runner', '/tmp/jcode-bench/20260719T023554Z-jcode-solo-gpt-5.4-float-print/tasks/float-print/.build/corpus_101.bin']' died with <Signals.SIGSEGV: 11>. Exit code: 1

{"file_path": "verify/runner.c", "intent": "Read runner to reproduce callgrind crash path", "limit": 220, "start_line": 1}

1 // runner.c — cost driver for float-print. Reads uint32 bit patterns, 2 // calls float_print on each. Run under callgrind with --toggle-collect. 3 #include <stdint.h> 4 #include <stddef.h> 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <string.h> 8 9 #ifdef RUNNER_GIVEN 10 size_t given_float_print(float f, char *out); 11 #define float_print given_float_print 12 #else 13 size_t float_print(float f, char *out); 14 #endif 15 16 int main(int argc, char **argv) { 17 if (argc < 2) { fprintf(stderr, "usage: runner CORPUS\n"); return 2; } 18 FILE *f = fopen(argv[1], "rb"); 19 if (!f) { perror("corpus"); return 2; } 20 fseek(f, 0, SEEK_END); 21 long sz = ftell(f); 22 fseek(f, 0, SEEK_SET); 23 uint32_t *bits = malloc((size_t)sz); 24 if (fread(bits, 1, (size_t)sz, f) != (size_t)sz) { perror("read"); return 2; } 25 fclose(f); 26 size_t n = (size_t)sz / 4; 27 char out[40]; 28 unsigned long long checksum = 0; 29 for (size_t i = 0; i < n; i++) { 30 float v; 31 memcpy(&v, &bits[i], 4); 32 size_t r = float_print(v, out); 33 checksum += r + (unsigned char)out[0]; 34 } 35 printf("runner: %zu floats, checksum %llu\n", n, checksum); 36 return 0; 37 }

{"command": "set -euo pipefail\nscratch=\"$JCODE_SCRATCH_DIR/float-print-debug\"\nmkdir -p \"$scratch\"\ncc -O1 -g -fsanitize=address,undefined -std=c17 -I submission submission/solve.c verify/runner.c -o \"$scratch/runner_asan\" -lm\nif [ ! -f .build/corpus_101.bin ]; then python3 verify/gen_corpus.py 101 .build/corpus_101.bin; fi\n\"$scratch/runner_asan\" .build/corpus_101.bin\n", "intent": "Reproduce seed-101 runner under ASan/UBSan", "notify": false, "run_in_background": false, "timeout": 1200000, "wake": false}

================================================================= ==618==ERROR: LeakSanitizer: detected memory leaks Direct leak of 200000 byte(s) in 1 object(s) allocated from: #0 0x2b6fa1dd00c1 in malloc (/usr/lib/libasan.so.8+0x12c0c1) (BuildId: b28f87d70f4aadfdfe6abce3776c226f5569bd6a) #1 0x5572a1a0d420 in main verify/runner.c:23 SUMMARY: AddressSanitizer: 200000 byte(s) leaked in 1 allocation(s). Exit code: 1

{"command": "set -euo pipefail\nif [ ! -f .build/corpus_101.bin ]; then python3 verify/gen_corpus.py 101 .build/corpus_101.bin; fi\nvalgrind --tool=callgrind --toggle-collect=float_print --collect-atstart=no --dump-line=no --callgrind-out-file=.build/manual.callgrind.out .build/runner .build/corpus_101.bin", "intent": "Reproduce callgrind crash directly on seed-101 corpus", "notify": false, "run_in_background": false, "timeout": 1200000, "wake": false}

==632== Callgrind, a call-graph generating cache profiler ==632== Copyright (C) 2002-2017, and GNU GPL'd, by Josef Weidendorfer et al. ==632== Using Valgrind-3.25.1 and LibVEX; rerun with -h for copyright info ==632== Command: .build/runner .build/corpus_101.bin ==632== ==632== Using source line as position. ==632== For interactive control, run 'callgrind_control -h'. runner: 50000 floats, checksum 3030480 ==632== ==632== Events : Ir ==632== Collected : 11653815 ==632== ==632== I refs: 11,653,815 --- Command finished with exit code: 0 ---

{"command": "set -euo pipefail\nprintf '=== rerun grade seed 101 ===\\n'\n./grade --seed 101\nprintf '\\n=== grade seed 202 ===\\n'\n./grade --seed 202\nprintf '\\n=== grade seed 303 ===\\n'\n./grade --seed 303\n", "intent": "Rerun multiple seeded grades after nonreproducible callgrind failure", "notify": false, "run_in_background": false, "timeout": 1800000, "wake": false}

=== rerun grade seed 101 === build 0.9s verify 7.2s PASS measure 6.8s 59,601,990 instructions (given: 4,479,568,761) SCORE +6.2319 (75.158x) === grade seed 202 === build 0.9s verify 7.1s PASS measure 6.9s 59,559,786 instructions (given: 4,481,978,093) SCORE +6.2337 (75.252x) === grade seed 303 === build 0.9s verify 7.0s PASS measure 6.9s 59,616,239 instructions (given: 4,485,148,327) SCORE +6.2333 (75.234x) --- Command finished with exit code: 0 ---

{"command": "python3 - <<'PY'\nimport json\nbest=None\nbest_full=None\nrecs=[]\nfor line in open('scores.jsonl'):\n rec=json.loads(line)\n recs.append(rec)\n if best is None or rec['score']>best['score']:\n best=rec\n if rec['full_gate'] and (best_full is None or rec['score']>best_full['score']):\n best_full=rec\nprint('best_overall', best)\nprint('best_full', best_full)\nprint('last5')\nfor r in recs[-5:]:\n print(r)\nPY", "intent": "Summarize recorded scores after revalidation", "notify": false, "run_in_background": false, "timeout": 120000, "wake": false}

best_overall {'ts': '2026-07-19T03:24:39Z', 'seed': 202, 'cost': 59559786, 'given_cost': 4481978093, 'score': 6.2337, 'full_gate': False} best_full {'ts': '2026-07-19T03:23:20Z', 'seed': 29433, 'cost': 59672118, 'given_cost': 4487121571, 'score': 6.2326, 'full_gate': True} last5 {'ts': '2026-07-19T02:40:07Z', 'seed': 28792, 'cost': 59634664, 'given_cost': 4481392741, 'score': 6.2317, 'full_gate': False} {'ts': '2026-07-19T03:23:20Z', 'seed': 29433, 'cost': 59672118, 'given_cost': 4487121571, 'score': 6.2326, 'full_gate': True} {'ts': '2026-07-19T03:24:24Z', 'seed': 101, 'cost': 59601990, 'given_cost': 4479568761, 'score': 6.2319, 'full_gate': False} {'ts': '2026-07-19T03:24:39Z', 'seed': 202, 'cost': 59559786, 'given_cost': 4481978093, 'score': 6.2337, 'full_gate': False} {'ts': '2026-07-19T03:24:54Z', 'seed': 303, 'cost': 59616239, 'given_cost': 4485148327, 'score': 6.2333, 'full_gate': False} --- Command finished with exit code: 0 ---

{"goals": [{"end_to_end_ownership": 98, "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline. Before finalizing, collect at least one exhaustive correctness result and multiple independent seeded grade results.", "group": "float-print optimization", "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session, backed by one full 2^32-bit gate and additional independent seeded rechecks.", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100}], "intent": "Close revalidated float-print benchmark work", "todos": [{"completion_confidence": 100, "confidence": 100, "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "group": "float-print optimization", "id": "read-spec-code", "priority": "high", "status": "completed"}, {"completion_confidence": 97, "confidence": 97, "content": "Profile and optimize submission implementation with repeated grade runs", "group": "float-print optimization", "id": "optimize-grade", "priority": "high", "status": "completed"}, {"completion_confidence": 96, "confidence": 96, "content": "Recheck final implementation with independent evidence, record best score, and summarize readiness", "group": "float-print optimization", "id": "finalize-report", "priority": "high", "status": "completed"}]}

[ { "content": "Read spec and current submission implementation to understand correctness requirements and hot paths", "status": "completed", "priority": "high", "id": "read-spec-code", "group": "float-print optimization", "confidence": 100, "completion_confidence": 100, "confidence_history": [ 95, 100 ] }, { "content": "Profile and optimize submission implementation with repeated grade runs", "status": "completed", "priority": "high", "id": "optimize-grade", "group": "float-print optimization", "confidence": 97, "completion_confidence": 97, "confidence_history": [ 85, 97 ] }, { "content": "Recheck final implementation with independent evidence, record best score, and summarize readiness", "status": "completed", "priority": "high", "id": "finalize-report", "group": "float-print optimization", "confidence": 96, "completion_confidence": 96, "confidence_history": [ 80, 100, 95, 96 ] } ] Goals: [ { "group": "float-print optimization", "user_intention": "Improve submission/solve.c as much as possible under benchmark rules and report the best final score.", "user_intention_alignment": 100, "hill_climbability": 99, "objective": "Increase the best verified ./grade score by reducing deterministic callgrind instruction count of submission/solve.c while maintaining exact output on every verifier input. Success is a final passing grade with the highest observed score in scores.jsonl for this session, backed by one full 2^32-bit gate and additional independent seeded rechecks.", "feedback_loop": "For each iteration: inspect implementation, make one targeted change in submission/, run ./grade, record reported score and whether correctness passes, keep only changes that improve or preserve the best verified score, and use scores.jsonl plus grader output as the comparison baseline. Before finalizing, collect at least one exhaustive correctness result and multiple independent seeded grade results.", "end_to_end_ownership": 98 } ]