[tests] Precommit for generalization of D112262

Author: preames

llvm/test/Transforms/IndVarSimplify/finite-exit-comparisons.ll

@@ -792,3 +792,114 @@ for.body:                                         ; preds = %entry, %for.body
 for.end:                                          ; preds = %for.body, %entry
   ret void
 }
+
+; Show that these transformatios also work with inverted operands
+; We only both to do this with slt/ult, but it applies to all predicates.
+
+define void @slt_constant_lhs(i16 %n.raw, i8 %start) mustprogress {
+; CHECK-LABEL: @slt_constant_lhs(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], [[FOR_BODY]] ], [ [[START:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i8 [[IV]], 1
+; CHECK-NEXT:    [[ZEXT:%.*]] = zext i8 [[IV_NEXT]] to i16
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i16 254, [[ZEXT]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END:%.*]]
+; CHECK:       for.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %iv = phi i8 [ %iv.next, %for.body ], [ %start, %entry ]
+  %iv.next = add i8 %iv, 1
+  %zext = zext i8 %iv.next to i16
+  %cmp = icmp slt i16 254, %zext
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+define void @slt_non_constant_lhs(i16 %n) mustprogress {
+; CHECK-LABEL: @slt_non_constant_lhs(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], [[FOR_BODY]] ], [ 0, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i8 [[IV]], 1
+; CHECK-NEXT:    [[ZEXT:%.*]] = zext i8 [[IV_NEXT]] to i16
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i16 [[N:%.*]], [[ZEXT]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END:%.*]]
+; CHECK:       for.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %iv = phi i8 [ %iv.next, %for.body ], [ 0, %entry ]
+  %iv.next = add i8 %iv, 1
+  %zext = zext i8 %iv.next to i16
+  %cmp = icmp slt i16 %n, %zext
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+define void @ult_constant_lhs(i16 %n.raw, i8 %start) mustprogress {
+; CHECK-LABEL: @ult_constant_lhs(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], [[FOR_BODY]] ], [ [[START:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i8 [[IV]], 1
+; CHECK-NEXT:    [[ZEXT:%.*]] = zext i8 [[IV_NEXT]] to i16
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i16 254, [[ZEXT]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END:%.*]]
+; CHECK:       for.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %iv = phi i8 [ %iv.next, %for.body ], [ %start, %entry ]
+  %iv.next = add i8 %iv, 1
+  %zext = zext i8 %iv.next to i16
+  %cmp = icmp ult i16 254, %zext
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+define void @ult_non_constant_lhs(i16 %n) mustprogress {
+; CHECK-LABEL: @ult_non_constant_lhs(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], [[FOR_BODY]] ], [ 0, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i8 [[IV]], 1
+; CHECK-NEXT:    [[ZEXT:%.*]] = zext i8 [[IV_NEXT]] to i16
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i16 [[N:%.*]], [[ZEXT]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END:%.*]]
+; CHECK:       for.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %iv = phi i8 [ %iv.next, %for.body ], [ 0, %entry ]
+  %iv.next = add i8 %iv, 1
+  %zext = zext i8 %iv.next to i16
+  %cmp = icmp ult i16 %n, %zext
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}