diff --git a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp index c43cb39a5918a..01fead12dc083 100644 --- a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp +++ b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp @@ -182,6 +182,21 @@ static bool eliminateConstraints(Function &F, DominatorTree &DT) { continue; } + // If the condition is an AND of 2 compares and the true successor only has + // the current block as predecessor, queue both conditions for the true + // successor. + if (match(Br->getCondition(), m_And(m_Cmp(), m_Cmp()))) { + BasicBlock *TrueSuccessor = Br->getSuccessor(0); + if (TrueSuccessor->getSinglePredecessor()) { + auto *AndI = cast(Br->getCondition()); + WorkList.emplace_back(DT.getNode(TrueSuccessor), + cast(AndI->getOperand(0)), false); + WorkList.emplace_back(DT.getNode(TrueSuccessor), + cast(AndI->getOperand(1)), false); + } + continue; + } + auto *CmpI = dyn_cast(Br->getCondition()); if (!CmpI) continue; diff --git a/llvm/test/Transforms/ConstraintElimination/and.ll b/llvm/test/Transforms/ConstraintElimination/and.ll index 2e7f61659dac1..d8962b39ebd5a 100644 --- a/llvm/test/Transforms/ConstraintElimination/and.ll +++ b/llvm/test/Transforms/ConstraintElimination/and.ll @@ -12,11 +12,11 @@ define i32 @test_and_ule(i32 %x, i32 %y, i32 %z, i32 %a) { ; CHECK-NEXT: br i1 [[AND]], label [[BB1:%.*]], label [[EXIT:%.*]] ; CHECK: bb1: ; CHECK-NEXT: [[T_1:%.*]] = icmp ule i32 [[X]], [[Z]] -; CHECK-NEXT: call void @use(i1 [[T_1]]) +; CHECK-NEXT: call void @use(i1 true) ; CHECK-NEXT: [[T_2:%.*]] = icmp ule i32 [[X]], [[Y]] -; CHECK-NEXT: call void @use(i1 [[T_2]]) +; CHECK-NEXT: call void @use(i1 true) ; CHECK-NEXT: [[T_3:%.*]] = icmp ule i32 [[Y]], [[Z]] -; CHECK-NEXT: call void @use(i1 [[T_3]]) +; CHECK-NEXT: call void @use(i1 true) ; CHECK-NEXT: [[C_3:%.*]] = icmp ule i32 [[X]], [[A:%.*]] ; CHECK-NEXT: call void @use(i1 [[C_3]]) ; CHECK-NEXT: ret i32 10