doh: fix undefined behaviour in swap#4350
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The undefined behaviour is annoying when running fuzzing with sanitizers. The codegen is the same, but the meaning is now not up for dispute. See https://cppinsights.io/s/516a2ff4 By incrementing the pointer first, both gcc and clang recognize this as a bswap and optimizes it to a single instruction. See https://godbolt.org/z/994Zpx
bagder
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There are certainly several ways to fix the undefined behavior (even if most compilers seem to be fine with it), but if this has the benefit that it generates better code I'm all for it!
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Thanks! |
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The undefined behaviour is annoying when running fuzzing with
sanitizers. The codegen is the same, but the meaning is now
not up for dispute. See https://cppinsights.io/s/516a2ff4
By incrementing the pointer first, both gcc and clang recognize this
as a bswap and optimizes it to a single instruction.
See https://godbolt.org/z/994Zpx