diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 19 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/logical-select.ll | 20 |
2 files changed, 39 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 8ec775b0c3..4ec36ad151 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -4337,6 +4337,25 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { return BinaryOperator::CreateAnd(V1, Or); } } + + // (A & sext(C0)) | (B & ~sext(C0) -> C0 ? A : B + if (isa<SExtInst>(C) && + cast<User>(C)->getOperand(0)->getType() == Type::Int1Ty) { + if (match(D, m_Not(m_Value(C)))) + return SelectInst::Create(cast<User>(C)->getOperand(0), A, B); + // And commutes, try both ways. + if (match(B, m_Not(m_Value(C)))) + return SelectInst::Create(cast<User>(C)->getOperand(0), A, D); + } + // Or commutes, try both ways. + if (isa<SExtInst>(D) && + cast<User>(D)->getOperand(0)->getType() == Type::Int1Ty) { + if (match(C, m_Not(m_Value(D)))) + return SelectInst::Create(cast<User>(D)->getOperand(0), A, B); + // And commutes, try both ways. + if (match(A, m_Not(m_Value(D)))) + return SelectInst::Create(cast<User>(D)->getOperand(0), C, B); + } } // (X >> Z) | (Y >> Z) -> (X|Y) >> Z for all shifts. diff --git a/test/Transforms/InstCombine/logical-select.ll b/test/Transforms/InstCombine/logical-select.ll new file mode 100644 index 0000000000..6369badee6 --- /dev/null +++ b/test/Transforms/InstCombine/logical-select.ll @@ -0,0 +1,20 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep select | count 2 + +define i32 @foo(i32 %a, i32 %b, i32 %c, i32 %d) nounwind { + %e = icmp slt i32 %a, %b + %f = sext i1 %e to i32 + %g = and i32 %c, %f + %h = xor i32 %f, -1 + %i = and i32 %d, %h + %j = or i32 %g, %i + ret i32 %j +} +define i32 @bar(i32 %a, i32 %b, i32 %c, i32 %d) nounwind { + %e = icmp slt i32 %a, %b + %f = sext i1 %e to i32 + %g = and i32 %c, %f + %h = xor i32 %f, -1 + %i = and i32 %d, %h + %j = or i32 %i, %g + ret i32 %j +} |