diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp | 40 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/select.ll | 52 |
2 files changed, 92 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index 37eb8317f00..6f26f7f5cd1 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -1643,6 +1643,46 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) { } } + // Try to simplify a binop sandwiched between 2 selects with the same + // condition. + // select(C, binop(select(C, X, Y), W), Z) -> select(C, binop(X, W), Z) + BinaryOperator *TrueBO; + if (match(TrueVal, m_OneUse(m_BinOp(TrueBO)))) { + if (auto *TrueBOSI = dyn_cast<SelectInst>(TrueBO->getOperand(0))) { + if (TrueBOSI->getCondition() == CondVal) { + TrueBO->setOperand(0, TrueBOSI->getTrueValue()); + Worklist.Add(TrueBO); + return &SI; + } + } + if (auto *TrueBOSI = dyn_cast<SelectInst>(TrueBO->getOperand(1))) { + if (TrueBOSI->getCondition() == CondVal) { + TrueBO->setOperand(1, TrueBOSI->getTrueValue()); + Worklist.Add(TrueBO); + return &SI; + } + } + } + + // select(C, Z, binop(select(C, X, Y), W)) -> select(C, Z, binop(Y, W)) + BinaryOperator *FalseBO; + if (match(FalseVal, m_OneUse(m_BinOp(FalseBO)))) { + if (auto *FalseBOSI = dyn_cast<SelectInst>(FalseBO->getOperand(0))) { + if (FalseBOSI->getCondition() == CondVal) { + FalseBO->setOperand(0, FalseBOSI->getFalseValue()); + Worklist.Add(FalseBO); + return &SI; + } + } + if (auto *FalseBOSI = dyn_cast<SelectInst>(FalseBO->getOperand(1))) { + if (FalseBOSI->getCondition() == CondVal) { + FalseBO->setOperand(1, FalseBOSI->getFalseValue()); + Worklist.Add(FalseBO); + return &SI; + } + } + } + if (BinaryOperator::isNot(CondVal)) { SI.setOperand(0, BinaryOperator::getNotArgument(CondVal)); SI.setOperand(1, FalseVal); diff --git a/llvm/test/Transforms/InstCombine/select.ll b/llvm/test/Transforms/InstCombine/select.ll index e49639b3024..4a361cdc4ea 100644 --- a/llvm/test/Transforms/InstCombine/select.ll +++ b/llvm/test/Transforms/InstCombine/select.ll @@ -1490,3 +1490,55 @@ entry: %1 = select <4 x i1> %0, <4 x float> <float 0xFFFFFFFFE0000000, float 0xFFFFFFFFE0000000, float 0xFFFFFFFFE0000000, float 0xFFFFFFFFE0000000>, <4 x float> zeroinitializer ret <4 x float> %1 } + +; select(C, binop(select(C, X, Y), W), Z) -> select(C, binop(X, W), Z) +define i8 @test87(i1 %cond, i8 %w, i8 %x, i8 %y, i8 %z) { +; CHECK-LABEL: @test87( +; CHECK-NEXT: [[B:%.*]] = add i8 [[X:%.*]], [[W:%.*]] +; CHECK-NEXT: [[C:%.*]] = select i1 [[COND:%.*]], i8 [[B]], i8 [[Z:%.*]] +; CHECK-NEXT: ret i8 [[C]] +; + %a = select i1 %cond, i8 %x, i8 %y + %b = add i8 %a, %w + %c = select i1 %cond, i8 %b, i8 %z + ret i8 %c +} + +; select(C, binop(select(C, X, Y), W), Z) -> select(C, Z, binop(Y, W)) +define i8 @test88(i1 %cond, i8 %w, i8 %x, i8 %y, i8 %z) { +; CHECK-LABEL: @test88( +; CHECK-NEXT: [[B:%.*]] = sub i8 [[Y:%.*]], [[W:%.*]] +; CHECK-NEXT: [[C:%.*]] = select i1 [[COND:%.*]], i8 [[Z:%.*]], i8 [[B]] +; CHECK-NEXT: ret i8 [[C]] +; + %a = select i1 %cond, i8 %x, i8 %y + %b = sub i8 %a, %w + %c = select i1 %cond, i8 %z, i8 %b + ret i8 %c +} + +; select(C, Z, binop(W, select(C, X, Y))) -> select(C, binop(X, W), Z) +define i8 @test89(i1 %cond, i8 %w, i8 %x, i8 %y, i8 %z) { +; CHECK-LABEL: @test89( +; CHECK-NEXT: [[B:%.*]] = and i8 [[X:%.*]], [[W:%.*]] +; CHECK-NEXT: [[C:%.*]] = select i1 [[COND:%.*]], i8 [[B]], i8 [[Z:%.*]] +; CHECK-NEXT: ret i8 [[C]] +; + %a = select i1 %cond, i8 %x, i8 %y + %b = and i8 %w, %a + %c = select i1 %cond, i8 %b, i8 %z + ret i8 %c +} + +; select(C, Z, binop(W, select(C, X, Y))) -> select(C, Z, binop(W, Y)) +define i8 @test90(i1 %cond, i8 %w, i8 %x, i8 %y, i8 %z) { +; CHECK-LABEL: @test90( +; CHECK-NEXT: [[B:%.*]] = or i8 [[Y:%.*]], [[W:%.*]] +; CHECK-NEXT: [[C:%.*]] = select i1 [[COND:%.*]], i8 [[Z:%.*]], i8 [[B]] +; CHECK-NEXT: ret i8 [[C]] +; + %a = select i1 %cond, i8 %x, i8 %y + %b = or i8 %w, %a + %c = select i1 %cond, i8 %z, i8 %b + ret i8 %c +} |
