Skip to content

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

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

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

Changes from 2 commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
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
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 21 additions & 6 deletions src/coreclr/jit/lower.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4306,16 +4306,31 @@ GenTree* Lowering::OptimizeConstCompare(GenTree* cmp)
// operand bit size - it uses (bit_index MOD bit_size).
//

GenTree* lsh = cmp->gtGetOp2();
GenTree** lsh = &cmp->AsOp()->gtOp1;
GenTree** op = &cmp->AsOp()->gtOp2;
bool swapCompareOps = true;

if (lsh->OperIs(GT_LSH) && varTypeIsIntOrI(lsh->TypeGet()) && lsh->gtGetOp1()->IsIntegralConst(1))
if (!(*lsh)->OperIs(GT_LSH))
{
std::swap(lsh, op);
swapCompareOps = false;
}

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

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

*lsh = (*lsh)->gtGetOp2();

if (swapCompareOps)
{
std::swap(cmp->AsOp()->gtOp1, cmp->AsOp()->gtOp2);
}

cmp->gtGetOp2()->ClearContained();

return cmp->gtNext;
}
Expand Down
Loading