Re-apply r251050 with a for PR25421
The bug: I missed adding break statements in the switch / case.
Original commit message:
[SCEV] Teach SCEV some axioms about non-wrapping arithmetic
Summary:
- A s< (A + C)<nsw> if C > 0
- A s<= (A + C)<nsw> if C >= 0
- (A + C)<nsw> s< A if C < 0
- (A + C)<nsw> s<= A if C <= 0
Right now `C` needs to be a constant, but we can later generalize it to
be a non-constant if needed.
Reviewers: atrick, hfinkel, reames, nlewycky
Subscribers: sanjoy, llvm-commits
Differential Revision: http://reviews.llvm.org/D13686
llvm-svn: 252236
diff --git a/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll b/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll
index 89f6251..612f01e 100644
--- a/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll
+++ b/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll
@@ -447,6 +447,64 @@
ret void
}
+define void @func_21(i32* %length.ptr) {
+; CHECK-LABEL: @func_21(
+
+; This checks that the backedge condition, (I + 1) < Length - 1 implies
+; (I + 1) < Length
+ entry:
+ %length = load i32, i32* %length.ptr, !range !0
+ %lim = sub i32 %length, 1
+ %entry.cond = icmp sgt i32 %length, 1
+ br i1 %entry.cond, label %loop, label %leave
+
+ loop:
+; CHECK: loop:
+ %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ]
+ %iv.inc = add i32 %iv, 1
+ %range.check = icmp slt i32 %iv, %length
+ br i1 %range.check, label %be, label %leave
+; CHECK: br i1 true, label %be, label %leave.loopexit
+; CHECK: be:
+
+ be:
+ call void @side_effect()
+ %be.cond = icmp slt i32 %iv.inc, %lim
+ br i1 %be.cond, label %loop, label %leave
+
+ leave:
+ ret void
+}
+
+define void @func_22(i32* %length.ptr) {
+; CHECK-LABEL: @func_22(
+
+; This checks that the backedge condition, (I + 1) < Length - 1 implies
+; (I + 1) < Length
+ entry:
+ %length = load i32, i32* %length.ptr, !range !0
+ %lim = sub i32 %length, 1
+ %entry.cond = icmp sgt i32 %length, 1
+ br i1 %entry.cond, label %loop, label %leave
+
+ loop:
+; CHECK: loop:
+ %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ]
+ %iv.inc = add i32 %iv, 1
+ %range.check = icmp sle i32 %iv, %length
+ br i1 %range.check, label %be, label %leave
+; CHECK: br i1 true, label %be, label %leave.loopexit
+; CHECK: be:
+
+ be:
+ call void @side_effect()
+ %be.cond = icmp sle i32 %iv.inc, %lim
+ br i1 %be.cond, label %loop, label %leave
+
+ leave:
+ ret void
+}
+
define void @func_23(i32* %length.ptr) {
; CHECK-LABEL: @func_23(
entry: