diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/Reassociate.cpp | 14 | ||||
| -rw-r--r-- | llvm/test/Transforms/Reassociate/negation1.ll | 15 |
2 files changed, 27 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Scalar/Reassociate.cpp b/llvm/lib/Transforms/Scalar/Reassociate.cpp index d0cd48a3a26..b8fb25d0b9a 100644 --- a/llvm/lib/Transforms/Scalar/Reassociate.cpp +++ b/llvm/lib/Transforms/Scalar/Reassociate.cpp @@ -1034,13 +1034,23 @@ static unsigned FindInOperandList(SmallVectorImpl<ValueEntry> &Ops, unsigned i, Value *X) { unsigned XRank = Ops[i].Rank; unsigned e = Ops.size(); - for (unsigned j = i+1; j != e && Ops[j].Rank == XRank; ++j) + for (unsigned j = i+1; j != e && Ops[j].Rank == XRank; ++j) { if (Ops[j].Op == X) return j; + if (Instruction *I1 = dyn_cast<Instruction>(Ops[j].Op)) + if (Instruction *I2 = dyn_cast<Instruction>(X)) + if (I1->isIdenticalTo(I2)) + return j; + } // Scan backwards. - for (unsigned j = i-1; j != ~0U && Ops[j].Rank == XRank; --j) + for (unsigned j = i-1; j != ~0U && Ops[j].Rank == XRank; --j) { if (Ops[j].Op == X) return j; + if (Instruction *I1 = dyn_cast<Instruction>(Ops[j].Op)) + if (Instruction *I2 = dyn_cast<Instruction>(X)) + if (I1->isIdenticalTo(I2)) + return j; + } return i; } diff --git a/llvm/test/Transforms/Reassociate/negation1.ll b/llvm/test/Transforms/Reassociate/negation1.ll new file mode 100644 index 00000000000..34b943cf496 --- /dev/null +++ b/llvm/test/Transforms/Reassociate/negation1.ll @@ -0,0 +1,15 @@ +; RUN: opt < %s -reassociate -instcombine -S | FileCheck %s + +; Test that we can turn things like A*B + X - A*B -> X. + +define i32 @test1(i32 %a, i32 %b, i32 %x) { +; CHECK-LABEL: test1 +; CHECK: ret i32 %x + + %c = mul i32 %a, %b + %d = add i32 %c, %x + %c1 = mul i32 %a, %b + %f = sub i32 %d, %c1 + ret i32 %f +} + |
