diff --git a/llvm/test/Transforms/LoopStrengthReduce/RISCV/icmp-zero.ll b/llvm/test/Transforms/LoopStrengthReduce/RISCV/icmp-zero.ll index 8835c0c44d9d71..f0aa0f2e93f43c 100644 --- a/llvm/test/Transforms/LoopStrengthReduce/RISCV/icmp-zero.ll +++ b/llvm/test/Transforms/LoopStrengthReduce/RISCV/icmp-zero.ll @@ -351,4 +351,36 @@ exit: ret void } +; Loop invariant does not neccessarily mean dominating the loop. Forming +; an ICmpZero from this example would be illegal even though the operands +; to the compare are loop invariant. +define void @loop_invariant_definition(i64 %arg) { +; CHECK-LABEL: @loop_invariant_definition( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[T1:%.*]] +; CHECK: t1: +; CHECK-NEXT: [[LSR_IV:%.*]] = phi i64 [ [[LSR_IV_NEXT:%.*]], [[T1]] ], [ -1, [[ENTRY:%.*]] ] +; CHECK-NEXT: [[LSR_IV_NEXT]] = add nsw i64 [[LSR_IV]], 1 +; CHECK-NEXT: br i1 true, label [[T4:%.*]], label [[T1]] +; CHECK: t4: +; CHECK-NEXT: [[T5:%.*]] = trunc i64 [[LSR_IV_NEXT]] to i32 +; CHECK-NEXT: [[T6:%.*]] = add i32 [[T5]], 1 +; CHECK-NEXT: [[T7:%.*]] = icmp eq i32 [[T5]], [[T6]] +; CHECK-NEXT: ret void +; +entry: + br label %t1 + +t1: ; preds = %1, %0 + %t2 = phi i64 [ %t3, %t1 ], [ 0, %entry ] + %t3 = add nuw i64 %t2, 1 + br i1 true, label %t4, label %t1 + +t4: ; preds = %1 + %t5 = trunc i64 %t2 to i32 + %t6 = add i32 %t5, 1 + %t7 = icmp eq i32 %t5, %t6 + ret void +} + declare i64 @llvm.vscale.i64()