[release/6.0] Fix incorrect SIMD temp allocation for Vector256 with AVX2 disabled #58850
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The NI_Vector256_GetElement intrinsic, in some situations, requires a stack temporary. With AVX2 disabled, this temporary was getting allocated as a TYP_SIMD16 instead of a TYP_SIMD32, leading to overwriting the local variable. Add a type argument to the temp variable allocation, and allocate the temp as the largest sized type required by any use. Fixes #58295
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Tagging subscribers to this area: @JulieLeeMSFT Issue DetailsBackport of #58820 to release/6.0 /cc @BruceForstall Customer ImpactTestingRisk
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@tannergooding @dotnet/jit-contrib PTAL -- port of fix to release/6.0 |
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CC @jeffschwMSFT for 6.0 backport. |
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Please fill in the customer impact and request a code review. |
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@jeffschwMSFT This is ready now |
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Backport of #58820 to release/6.0
/cc @BruceForstall
Customer Impact
Using the
Vector256<T>GetElement API on a machine with AVX but without AVX2 could, in some instances, lead to a corrupt stack frame and data corruption.Testing
Manual testing of the fix on the repro case, as well as SuperPMI asm diffs to determine other impact of the change, as well as standard PR CI testing.
Risk
Low.