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/pr25421.ll b/llvm/test/Transforms/IndVarSimplify/pr25421.ll
new file mode 100644
index 0000000..efb71f9
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/pr25421.ll
@@ -0,0 +1,30 @@
+; RUN: opt -S -indvars < %s | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.11.0"
+
+declare void @use(i1)
+
+define void @f(i32 %x) {
+; CHECK-LABEL: @f(
+ entry:
+ %conv = sext i32 %x to i64
+ %sub = add i64 %conv, -1
+ %ec = icmp sgt i32 %x, 0
+ br i1 %ec, label %loop, label %leave
+
+ loop:
+; CHECK: loop:
+ %iv = phi i64 [ 0, %entry ], [ %iv.inc, %loop ]
+ %iv.inc = add i64 %iv, 1
+ %cmp = icmp slt i64 %iv, %sub
+ call void @use(i1 %cmp)
+; CHECK: call void @use(i1 %cmp)
+; CHECK-NOT: call void @use(i1 true)
+
+ %be.cond = icmp slt i64 %iv.inc, %conv
+ br i1 %be.cond, label %loop, label %leave
+
+ leave:
+ ret void
+}