JIT: Add out-of-bounds fallback for AdvSimd.ShiftRightLogical #105777
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ghost
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area-CodeGen-coreclr
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cc @dotnet/jit-contrib, @tannergooding PTAL. |
tannergooding
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Jul 31, 2024
jakobbotsch
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Jul 31, 2024
src/coreclr/jit/hwintrinsicarm64.cpp
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| impSpillSideEffect(true, | ||
| verCurrentState.esStackDepth - 2 DEBUGARG("Spilling op1 side effects for HWIntrinsic")); | ||
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| GenTree* op2 = impPopStack().val; | ||
| GenTree* op1 = impSIMDPopStack(); | ||
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| // AdvSimd.ShiftLogical does right-shifts with negative immediates, hence the negation | ||
| GenTree* tmpOp = | ||
| gtNewSimdCreateBroadcastNode(simdType, gtNewOperNode(GT_NEG, genActualType(op2->TypeGet()), op2), | ||
| simdBaseJitType, genTypeSize(simdType)); | ||
| return gtNewSimdHWIntrinsicNode(simdType, op1, tmpOp, NI_AdvSimd_ShiftLogical, simdBaseJitType, | ||
| genTypeSize(simdType)); |
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I assumed we would need it since we do the same for AVX2/SSE intrinsics, but looks like we don't need it. Fixed.
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yep, we don't. Here op1 is still evaluated before op2 so all good
EgorBo
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Jul 31, 2024
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| // Licensed to the .NET Foundation under one or more agreements. | |||
| // The .NET Foundation licenses this file to you under the MIT license. | |||
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We usually copy-paste Fuzzlyn's header for repros
EgorBo
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Aug 1, 2024
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Fixes #105621. When its immediate is out-of-bounds,
AdvSimd.ShiftRightLogicalcan be transformed intoAdvSimd.ShiftLogical, which takes the immediate in a register. This meansAdvSimd.ShiftRightLogicalwill no longer throwArgumentOutOfRangeExceptionin Debug or Release; when optimizing, we'd previously fold the intrinsic away, thus creating behavioral discrepancies.