Avoid calling size() in valarray loops
#3968
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StephanTLavavej
approved these changes
Aug 16, 2023
|
I've also created DevCom-10442357 to optimize even without pre-indirection after more checks, it has some votes, but I'm skeptical, as other compilers miss the vectorization without pre-indirected size too, |
CaseyCarter
reviewed
Aug 29, 2023
CaseyCarter
approved these changes
Aug 29, 2023
|
I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed. |
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Thanks for convincing the compiler that |
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Resolves #3915
I've chosen "eliminating indirection helps vectorization" wording that does not mention aliasing.
The correctly looking formula would be "avoid suspected false aliasing" and it is confusing. The wording like "inhibit aliasing" is not quite correct, because the actual aliasing is not happening anyway.
I'm sure that wording mentioning "indirection" and "vectorization" strongly suggests what happening for those who familiar with the problem, and for those who are not, the margin of this variable declaration is too small to fit an explanation.