llvm-6502/test/Transforms/IndVarSimplify/pr22222.ll
Sanjoy Das 7ec1829823 Fix PR22222
The bug was introduced in r225282. r225282 assumed that sub X, Y is
the same as add X, -Y. This is not correct if we are going to upgrade
the sub to sub nuw. This change fixes the issue by making the
optimization ignore sub instructions.

Differential Revision: http://reviews.llvm.org/D6979



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226075 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 01:46:09 +00:00

47 lines
1.6 KiB
LLVM

; RUN: opt -indvars -S < %s | FileCheck %s
@b = common global i32 0, align 4
@c = common global i32 0, align 4
@a = common global i32 0, align 4
declare void @abort() #1
; Function Attrs: nounwind ssp uwtable
define i32 @main() {
entry:
%a.promoted13 = load i32* @a, align 4
br label %for.cond1.preheader
for.cond1.preheader: ; preds = %entry, %for.end
%or.lcssa14 = phi i32 [ %a.promoted13, %entry ], [ %or.lcssa, %for.end ]
%d.010 = phi i32 [ 1, %entry ], [ 0, %for.end ]
br label %for.body3
for.body3: ; preds = %for.cond1.preheader, %for.body3
%inc12 = phi i32 [ 0, %for.cond1.preheader ], [ %inc, %for.body3 ]
%or11 = phi i32 [ %or.lcssa14, %for.cond1.preheader ], [ %or, %for.body3 ]
; CHECK-NOT: sub nuw i32 %inc12, %d.010
; CHECK: sub i32 %inc12, %d.010
%add = sub i32 %inc12, %d.010
%or = or i32 %or11, %add
%inc = add i32 %inc12, 1
br i1 false, label %for.body3, label %for.end
for.end: ; preds = %for.body3
%or.lcssa = phi i32 [ %or, %for.body3 ]
br i1 false, label %for.cond1.preheader, label %for.end6
for.end6: ; preds = %for.end
%or.lcssa.lcssa = phi i32 [ %or.lcssa, %for.end ]
store i32 %or.lcssa.lcssa, i32* @a, align 4
%cmp7 = icmp eq i32 %or.lcssa.lcssa, -1
br i1 %cmp7, label %if.end, label %if.then
if.then: ; preds = %for.end6
tail call void @abort() #2
unreachable
if.end: ; preds = %for.end6
ret i32 0
}