Index: lib/Transforms/InstCombine/InstCombineCalls.cpp =================================================================== --- lib/Transforms/InstCombine/InstCombineCalls.cpp +++ lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -997,6 +997,17 @@ return EraseInstFromFunction(CI); break; } + case Intrinsic::invariant: { + // Canonicalize invariant(a && b) -> invariant(a); invariant(b); + Value *IIOperand = II->getArgOperand(0), *A, *B; + if (match(IIOperand, m_And(m_Value(A), m_Value(B)))) { + Builder->CreateCall(II->getCalledValue(), A, II->getName()); + Builder->CreateCall(II->getCalledValue(), B, II->getName()); + return EraseInstFromFunction(*II); + } + + break; + } } return visitCallSite(II); Index: test/Transforms/InstCombine/invariants.ll =================================================================== --- test/Transforms/InstCombine/invariants.ll +++ test/Transforms/InstCombine/invariants.ll @@ -115,6 +115,22 @@ ret i32 %and1 } +; Function Attrs: nounwind uwtable +define i32 @can1(i1 %a, i1 %b, i1 %c) { +entry: + %and1 = and i1 %a, %b + %and = and i1 %and1, %c + tail call void @llvm.invariant(i1 %and) + +; CHECK-LABEL: @can1 +; CHECK: call void @llvm.invariant(i1 %a) +; CHECK: call void @llvm.invariant(i1 %b) +; CHECK: call void @llvm.invariant(i1 %c) +; CHECK: ret i32 + + ret i32 5 +} + attributes #0 = { nounwind uwtable } attributes #1 = { nounwind }