GoKawiil
Tech News
A technical blog post lists concrete cases where GCC and Clang do not conform to the ISO C standard by default, including treatment of the asm keyword as a reserved extension and GCC's hardcoded FLT_ROUNDS macro that ignores runtime rounding-mode changes via fesetround. The author also flags unfinished coverage of the standard's five floating-point pragmas as an area of ongoing non-conformance.
A blog post examines C17 section 7.25.2.6, which governs error handling for strtod, strtof, strtold and related string-to-float conversion functions. It explains that these functions' ability to report overflow or underflow via errno depends on the math_errhandling macro, and that on libraries like musl where MATH_ERRNO is not advertised, there is no standard-compliant way to detect these conversion errors. The author notes that Linux man pages for these functions omit this detail entirely.
A developer investigating containerized Rust performance found that musl's default memory allocator is significantly slower than glibc's, not just under high concurrency but even on modest 4-core EC2 instances. Swapping in mimalloc or jemalloc narrows the gap but doesn't close it—one workload remained 26% slower—because several of musl's core memory routines are themselves inefficient, not just its allocator.