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JIT: Optimize bit-wise AND with a constant mask in combination with a left shift in a compare #111979

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Merged
merged 7 commits into from
Feb 4, 2025
Merged

JIT: Optimize bit-wise AND with a constant mask in combination with a left shift in a compare #111979

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f9bdee6
JIT: Optimize bit-wise AND with a constant mask in combination with …
varelen Jan 29, 2025
31c3ac3
JIT: Minimize code duplicate when lowering left shift with const
varelen Jan 31, 2025
f1d8d60
JIT: Include test/eq with operands switched containing left shift in …
varelen Jan 31, 2025
5783c3c
JIT: Improve code for optimizing test/eq with a left shift op
varelen Jan 31, 2025
3dd15ef
Merge branch 'main' into jit-use-bt-instruction-for-constant-mask-iss…
varelen Jan 31, 2025
9cf8b1b
Merge branch 'main' into jit-use-bt-instruction-for-constant-mask-iss…
varelen Feb 1, 2025
e189bb5
Merge branch 'main' into jit-use-bt-instruction-for-constant-mask-iss…
varelen Feb 3, 2025
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23 changes: 18 additions & 5 deletions src/coreclr/jit/lower.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4306,16 +4306,29 @@ GenTree* Lowering::OptimizeConstCompare(GenTree* cmp)
// operand bit size - it uses (bit_index MOD bit_size).
//

GenTree* lsh = cmp->gtGetOp2();
GenTree* lshRight = cmp->gtGetOp2();
GenTree* lshLeft = cmp->gtGetOp1();

if (lsh->OperIs(GT_LSH) && varTypeIsIntOrI(lsh->TypeGet()) && lsh->gtGetOp1()->IsIntegralConst(1))
if (lshRight->OperIs(GT_LSH) && varTypeIsIntOrI(lshRight->TypeGet()) && lshRight->gtGetOp1()->IsIntegralConst(1))
{
cmp->SetOper(cmp->OperIs(GT_TEST_EQ) ? GT_BITTEST_EQ : GT_BITTEST_NE);
cmp->AsOp()->gtOp2 = lsh->gtGetOp2();
cmp->AsOp()->gtOp2 = lshRight->gtGetOp2();
cmp->gtGetOp2()->ClearContained();

BlockRange().Remove(lsh->gtGetOp1());
BlockRange().Remove(lsh);
BlockRange().Remove(lshRight->gtGetOp1());
BlockRange().Remove(lshRight);

return cmp->gtNext;
}
else if (lshLeft->OperIs(GT_LSH) && varTypeIsIntOrI(lshLeft->TypeGet()) && lshLeft->gtGetOp1()->IsIntegralConst(1))
{
cmp->SetOper(cmp->OperIs(GT_TEST_EQ) ? GT_BITTEST_EQ : GT_BITTEST_NE);
cmp->AsOp()->gtOp1 = cmp->AsOp()->gtOp2;
cmp->AsOp()->gtOp2 = lshLeft->gtGetOp2();
cmp->gtGetOp2()->ClearContained();

BlockRange().Remove(lshLeft->gtGetOp1());
BlockRange().Remove(lshLeft);

return cmp->gtNext;
}
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