[release/8.0] JIT: Extract all side effects of the index in optRemoveRangeCheck #92210
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optRemoveRangeCheck extracts only GTF_ASG from the bounds check. If the BOUNDS_CHECK is complex, that results in silently dropping side effects on the floor (see the example case). The ideal fix is that we should always extract all side effects from the index and length operands, however this has large regressions because the length typically has an ARR_LENGTH that we then extract. This PR instead has a surgical fix for the problem case that can be backported to .NET 8. It extracts all side effects from the index, but keeps extracting only GTF_ASG from the length to get around the issue mentioned above. Fix #91862
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Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch Issue DetailsBackport of #92116 to release/8.0 /cc @jakobbotsch Customer ImpactTestingRiskIMPORTANT: If this backport is for a servicing release, please verify that:
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EgorBo
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Sep 18, 2023
jeffschwMSFT
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Backport of #92116 to release/8.0
/cc @jakobbotsch
Customer Impact
The JIT may silently discard some side effects that are part of the 'index' argument of some HW intrinsics.
Testing
Regression test included.
Risk
Low.