Remove usage of [[likely]] and [[unlikely]]
#5255
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GabrielDosReis
approved these changes
Jan 27, 2025
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I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed. |
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@GabrielDosReis informed me that the optimizer team discourages use of the
[[likely]]and[[unlikely]]attributes, and instead encourages PGO/SPGO. (This aligns with what I've always said, "don't help the compiler".) We've accumulated a fair amount of usage of these attributes, none of which was motivated by benchmarking. Let's remove this noise from our codebase. If we ever find places where it actually affects performance (presumably for Clang/LLVM, since C2 pays minimal attention to the attribute), we can decide what to do.[[likely]]and[[unlikely]]._LIKELY_X86_X64,_LIKELY_ARM_ARM64, and clang-format suppression._LIKELYand_UNLIKELY.