diff options
| author | @raghesh (Raghesh Aloor) <raghesh.a@gmail.com> | 2020-01-09 10:52:39 -0500 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2020-01-09 10:52:39 -0500 |
| commit | 6c04ef472a8739a60a7935f77edfbacd2f50eb73 (patch) | |
| tree | 535979b6af34ab81a13e97d292ee1c9fbafa9876 /llvm/lib | |
| parent | 0fa8f701ccf6f29544394b358f38b748e3f7ab24 (diff) | |
| download | bcm5719-llvm-6c04ef472a8739a60a7935f77edfbacd2f50eb73.tar.gz bcm5719-llvm-6c04ef472a8739a60a7935f77edfbacd2f50eb73.zip | |
[InstCombine] Z / (1.0 / Y) => (Y * Z)
This is a special case of Z / (X / Y) => (Y * Z) / X, with X = 1.0.
The m_OneUse check is avoided because even in the case of the
multiple uses for 1.0/Y, the number of instructions remain the same
and a division is replaced by a multiplication.
Differential Revision: https://reviews.llvm.org/D72319
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index f7b39d98d49..2774e46151f 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -1239,6 +1239,14 @@ Instruction *InstCombiner::visitFDiv(BinaryOperator &I) { Value *YZ = Builder.CreateFMulFMF(Y, Op0, &I); return BinaryOperator::CreateFDivFMF(YZ, X, &I); } + // Z / (1.0 / Y) => (Y * Z) + // + // This is a special case of Z / (X / Y) => (Y * Z) / X, with X = 1.0. The + // m_OneUse check is avoided because even in the case of the multiple uses + // for 1.0/Y, the number of instructions remain the same and a division is + // replaced by a multiplication. + if (match(Op1, m_FDiv(m_SpecificFP(1.0), m_Value(Y)))) + return BinaryOperator::CreateFMulFMF(Y, Op0, &I); } if (I.hasAllowReassoc() && Op0->hasOneUse() && Op1->hasOneUse()) { |
