[Test] Add test for miscompile described in PR57247

llvm/test/Transforms/IndVarSimplify/pr57247.ll

@@ -0,0 +1,50 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -passes=indvars < %s | FileCheck %s
+
+; We must NOT replace check against IV with check against invariant 0. It should fail.
+define i32 @test() {
+; CHECK-LABEL: @test(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_LOOP:%.*]]
+; CHECK:       outer.loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[OUTER_LATCH:%.*]] ]
+; CHECK-NEXT:    [[CHECK_1:%.*]] = icmp ult i32 [[IV]], 2
+; CHECK-NEXT:    br label [[INNER_LOOP:%.*]]
+; CHECK:       inner.loop:
+; CHECK-NEXT:    [[STOREMERGE611_I:%.*]] = phi i64 [ 0, [[OUTER_LOOP]] ], [ [[ADD_I:%.*]], [[INNER_LATCH:%.*]] ]
+; CHECK-NEXT:    br i1 [[CHECK_1]], label [[INNER_LATCH]], label [[EXIT:%.*]]
+; CHECK:       inner.latch:
+; CHECK-NEXT:    [[ADD_I]] = add nuw nsw i64 [[STOREMERGE611_I]], 1
+; CHECK-NEXT:    [[CMP5_I:%.*]] = icmp ult i64 [[STOREMERGE611_I]], 11
+; CHECK-NEXT:    br i1 [[CMP5_I]], label [[INNER_LOOP]], label [[OUTER_LATCH]]
+; CHECK:       outer.latch:
+; CHECK-NEXT:    [[IV_NEXT]] = add nsw i32 [[IV]], -1
+; CHECK-NEXT:    br label [[OUTER_LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[IV_LCSSA:%.*]] = phi i32 [ [[IV]], [[INNER_LOOP]] ]
+; CHECK-NEXT:    ret i32 [[IV_LCSSA]]
+;
+entry:
+  br label %outer.loop
+
+outer.loop:                                       ; preds = %outer.latch, %entry
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %outer.latch ]
+  %check_1 = icmp ult i32 %iv, 2
+  br label %inner.loop
+
+inner.loop:                                       ; preds = %inner.latch, %outer.loop
+  %storemerge611.i = phi i64 [ 0, %outer.loop ], [ %add.i, %inner.latch ]
+  br i1 %check_1, label %inner.latch, label %exit
+
+inner.latch:                                      ; preds = %inner.loop
+  %add.i = add i64 %storemerge611.i, 1
+  %cmp5.i = icmp ult i64 %storemerge611.i, 11
+  br i1 %cmp5.i, label %inner.loop, label %outer.latch
+
+outer.latch:                                      ; preds = %inner.latch
+  %iv.next = add i32 %iv, -1
+  br label %outer.loop
+
+exit:                                             ; preds = %inner.loop
+  ret i32 %iv
+}