[SCEV] Add pre-commit tests. NFC.

Author: dtcxzyw

llvm/test/Transforms/IndVarSimplify/pr126409.ll

@@ -0,0 +1,31 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -S -passes=indvars < %s | FileCheck %s
+
+define void @pr126409() {
+; CHECK-LABEL: define void @pr126409() {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[X:%.*]] = xor i32 0, 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp samesign ult i32 [[X]], 155
+; CHECK-NEXT:    br i1 [[CMP]], label %[[FOR_BODY_PREHEADER:.*]], label %[[IF_END:.*]]
+; CHECK:       [[FOR_BODY_PREHEADER]]:
+; CHECK-NEXT:    br label %[[FOR_BODY:.*]]
+; CHECK:       [[FOR_BODY]]:
+; CHECK-NEXT:    br i1 true, label %[[FOR_BODY]], label %[[IF_END_LOOPEXIT:.*]]
+; CHECK:       [[IF_END_LOOPEXIT]]:
+; CHECK-NEXT:    br label %[[IF_END]]
+; CHECK:       [[IF_END]]:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %x = xor i32 0, 1
+  %cmp = icmp samesign ult i32 %x, 155
+  br i1 %cmp, label %for.body, label %if.end
+
+for.body:
+  %phi = phi i8 [ 1, %for.body ], [ 0, %entry ]
+  %cmp2 = icmp slt i8 %phi, 1
+  br i1 %cmp2, label %for.body, label %if.end
+
+if.end:
+  ret void
+}