diff --git a/llvm/lib/Transforms/Scalar/NewGVN.cpp b/llvm/lib/Transforms/Scalar/NewGVN.cpp --- a/llvm/lib/Transforms/Scalar/NewGVN.cpp +++ b/llvm/lib/Transforms/Scalar/NewGVN.cpp @@ -2430,8 +2430,9 @@ Value *CondEvaluated = findConditionEquivalence(Cond); if (!CondEvaluated) { if (auto *I = dyn_cast(Cond)) { - auto Res = createExpression(I); - if (const auto *CE = dyn_cast(Res.Expr)) { + SmallPtrSet Visited; + auto Res = performSymbolicEvaluation(I, Visited); + if (const auto *CE = dyn_cast_or_null(Res.Expr)) { CondEvaluated = CE->getConstantValue(); Res.addExtraUserTo(I, AdditionalUsers); } else { diff --git a/llvm/test/Transforms/NewGVN/compare-condition-changes.ll b/llvm/test/Transforms/NewGVN/compare-condition-changes.ll new file mode 100644 --- /dev/null +++ b/llvm/test/Transforms/NewGVN/compare-condition-changes.ll @@ -0,0 +1,78 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -newgvn -S %s | FileCheck %s + +; Test cases to make sure the blocks are properly marked as executable, if the +; state of the branch condition changes. + +define i1 @test1() { +; CHECK-LABEL: @test1( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[CALL:%.*]] = tail call i1 @foo() +; CHECK-NEXT: br i1 [[CALL]], label [[THEN:%.*]], label [[ELSE:%.*]] +; CHECK: then: +; CHECK-NEXT: ret i1 true +; CHECK: else: +; CHECK-NEXT: ret i1 false +; +entry: + %call = tail call i1 @foo() + br i1 %call, label %then, label %else + +then: + ret i1 true + +else: + ret i1 false +} + +declare i1 @foo() + +; Make sure state changes are propagated across freeze to branches. +define void @test2(i1 %c) { +; CHECK-LABEL: @test2( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[LOOP_HEADER:%.*]] +; CHECK: loop.header: +; CHECK-NEXT: [[P_0:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[LOOP_LATCH:%.*]] ] +; CHECK-NEXT: [[P_1:%.*]] = phi i32 [ 1, [[ENTRY]] ], [ [[P_2:%.*]], [[LOOP_LATCH]] ] +; CHECK-NEXT: br label [[LOOP_BB_1:%.*]] +; CHECK: loop.bb.1: +; CHECK-NEXT: [[INC]] = add nsw i32 [[P_0]], 1 +; CHECK-NEXT: [[C_1:%.*]] = icmp slt i32 [[P_0]], 0 +; CHECK-NEXT: [[C_1_FREEZE:%.*]] = freeze i1 [[C_1]] +; CHECK-NEXT: br i1 [[C_1_FREEZE]], label [[LOOP_BB_2:%.*]], label [[LOOP_LATCH]] +; CHECK: loop.bb.2: +; CHECK-NEXT: br label [[LOOP_LATCH]] +; CHECK: loop.latch: +; CHECK-NEXT: [[P_2]] = phi i32 [ 0, [[LOOP_BB_2]] ], [ [[P_1]], [[LOOP_BB_1]] ] +; CHECK-NEXT: [[C_2:%.*]] = icmp eq i32 [[P_2]], 123 +; CHECK-NEXT: br i1 [[C_2]], label [[EXIT:%.*]], label [[LOOP_HEADER]] +; CHECK: exit: +; CHECK-NEXT: ret void +; +entry: + br label %loop.header + +loop.header: + %p.0 = phi i32 [ 0, %entry ], [ %p.3, %loop.latch ] + %p.1 = phi i32 [ 1, %entry ], [ %p.2, %loop.latch ] + br label %loop.bb.1 + +loop.bb.1: + %inc = add nsw i32 %p.0, 1 + %c.1 = icmp slt i32 %p.0, 0 + %c.1.freeze = freeze i1 %c.1 + br i1 %c.1.freeze, label %loop.bb.2, label %loop.latch + +loop.bb.2: + br label %loop.latch + +loop.latch: + %p.2 = phi i32 [ 0, %loop.bb.2 ], [ %p.1, %loop.bb.1 ] + %p.3 = phi i32 [ %inc, %loop.bb.2 ], [ %inc, %loop.bb.1 ] + %c.2 = icmp eq i32 %p.2, 123 + br i1 %c.2, label %exit, label %loop.header + +exit: + ret void +}