Build strict: -ffp-contract=off replaces -ffast-math on every target - #54
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Enacts the estate policy for mas-bandwidth network libraries (Glenn, 2026-08-24): network libraries build with -ffp-contract=off on GCC/Clang and /fp:precise on MSVC. reliable carried -ffast-math / /fp:fast; those are gone. reliable's wire format carries no floating point -- the floats are RTT/jitter/loss/bandwidth stats -- so this is the family floor rather than a wire fix, and BUILDING.md says exactly that to consumers. CI builds through CMakeLists.txt, so every CI leg now builds strict. Verified on this bench: Release build green, all 4 ctest suites pass (test, fuzz, soak, fuzz_target), the flag confirmed on the actual compile lines of reliable.c and test.cpp (--verbose), zero remaining -ffast-math occurrences. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The first CI run of the strict build failed to link every C executable on Linux: reliable.c:1493 calls pow() for the jitter stddev, and -ffast-math had been rewriting pow(x, 0.5f) into inline sqrt, so the library never needed libm and never linked it. Strict math keeps the call. Link m PUBLIC where it exists (Linux glibc; mac and Windows carry the math functions in the base runtime), and declare -lm in Libs.private for static pkg-config consumers. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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Enacts Glenn's standing estate policy (2026-08-24): "generally speaking, network libraries we work on require -ffp-contract=off." serialize sets and documents the flag; yojimbo came under the policy in mas-bandwidth/yojimbo#333; netcode's equivalent is mas-bandwidth/netcode#179. This brings reliable under it.
CMakeLists.txt replaces the global
-ffast-math(GCC/Clang) and/fp:fast(MSVC) with-ffp-contract=offand/fp:precise. Globaladd_compile_options, so every target — library, test, example, soak, stats, fuzz harnesses — builds strict, and since CI drives every leg through this file, CI now enforces the flag on all platforms. BUILDING.md gains a floating point section mirroring yojimbo's, stating the flags and the consumer requirement.Honesty about scope: reliable's wire format carries no floating point — the floats in reliable.c are the RTT, jitter, packet loss and bandwidth stats. So this is the policy's floor, not a wire fix; nothing measured wrong here today, and the docs say exactly that rather than claiming a mechanism this repo does not have. The floor exists because FMA is in the aarch64 baseline and absent from the x86-64 one, so any float arithmetic that ever nears the wire diverges bit-wise between architectures unless the family builds strict.
The fast-math flags date from the premake era; serialize made the same replacement, and on MSVC there is no fast-minus-contraction spelling at all, so strict-replaces-fast is the only shape consistent across compilers.
Verified on this bench (arm64 mac, AppleClang, Release): build green, all 4 ctest suites pass (test, fuzz, soak, fuzz_target),
-ffp-contract=offconfirmed on the actual compile lines ofreliable.candtest.cppviacmake --build --verbose, zero remainingffast-mathoccurrences in the build output.🤖 Generated with Claude Code