sepavloff added a comment. In D104854#2838754 <https://reviews.llvm.org/D104854#2838754>, @craig.topper wrote:
> Doesn't gcc also fold isnan to false under fast math? If we diverge here that > means your code would only work correctly with clang. GCC does the same transformation, ICC and MSVC do not: https://godbolt.org/z/ovboWqPeb. Both clang and GCC do this transformation only with optimization level > 0. With -O0 both produce code that does real check, so semantic of the produced code is different depending on optimization level, it looks more like a bug rather than feature. There is a GCC ticket: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84949, which refers to the similar thing. It is created against to libstdc++ but the reason is in the compiler. In one on the comments there (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84949#c8) an opinion is expressed: ... My conclusion: std::numeric_limits means "has NaN bitpattern" and "has IEC559 bit layout" not "has NaNs with NaN behavior" and "has IEC559 behavior". So this behavior is considered as incorrect. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D104854/new/ https://reviews.llvm.org/D104854 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
