llvm/test/Transforms/IndVarSimplify/strengthen-overflow.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

109 lines
2.4 KiB
LLVM

; RUN: opt < %s -indvars -S | FileCheck %s
define i32 @test.signed.add.0(i32* %array, i32 %length, i32 %init) {
; CHECK-LABEL: @test.signed.add.0
entry:
%upper = icmp slt i32 %init, %length
br i1 %upper, label %loop, label %exit
loop:
; CHECK-LABEL: loop
%civ = phi i32 [ %init, %entry ], [ %civ.inc, %latch ]
%civ.inc = add i32 %civ, 1
; CHECK: %civ.inc = add nsw i32 %civ, 1
%cmp = icmp slt i32 %civ.inc, %length
br i1 %cmp, label %latch, label %break
latch:
store i32 0, i32* %array
%check = icmp slt i32 %civ.inc, %length
br i1 %check, label %loop, label %break
break:
ret i32 %civ.inc
exit:
ret i32 42
}
define i32 @test.signed.add.1(i32* %array, i32 %length, i32 %init) {
; CHECK-LABEL: @test.signed.add.1
entry:
%upper = icmp sle i32 %init, %length
br i1 %upper, label %loop, label %exit
loop:
; CHECK-LABEL: loop
%civ = phi i32 [ %init, %entry ], [ %civ.inc, %latch ]
%civ.inc = add i32 %civ, 1
; CHECK: %civ.inc = add i32 %civ, 1
%cmp = icmp slt i32 %civ.inc, %length
br i1 %cmp, label %latch, label %break
latch:
store i32 0, i32* %array
%check = icmp slt i32 %civ.inc, %length
br i1 %check, label %loop, label %break
break:
ret i32 %civ.inc
exit:
ret i32 42
}
define i32 @test.unsigned.add.0(i32* %array, i32 %length, i32 %init) {
; CHECK-LABEL: @test.unsigned.add.0
entry:
%upper = icmp ult i32 %init, %length
br i1 %upper, label %loop, label %exit
loop:
; CHECK-LABEL: loop
%civ = phi i32 [ %init, %entry ], [ %civ.inc, %latch ]
%civ.inc = add i32 %civ, 1
; CHECK: %civ.inc = add nuw i32 %civ, 1
%cmp = icmp slt i32 %civ.inc, %length
br i1 %cmp, label %latch, label %break
latch:
store i32 0, i32* %array
%check = icmp ult i32 %civ.inc, %length
br i1 %check, label %loop, label %break
break:
ret i32 %civ.inc
exit:
ret i32 42
}
define i32 @test.unsigned.add.1(i32* %array, i32 %length, i32 %init) {
; CHECK-LABEL: @test.unsigned.add.1
entry:
%upper = icmp ule i32 %init, %length
br i1 %upper, label %loop, label %exit
loop:
; CHECK-LABEL: loop
%civ = phi i32 [ %init, %entry ], [ %civ.inc, %latch ]
%civ.inc = add i32 %civ, 1
; CHECK: %civ.inc = add i32 %civ, 1
%cmp = icmp slt i32 %civ.inc, %length
br i1 %cmp, label %latch, label %break
latch:
store i32 0, i32* %array
%check = icmp ult i32 %civ.inc, %length
br i1 %check, label %loop, label %break
break:
ret i32 %civ.inc
exit:
ret i32 42
}
!0 = !{i32 0, i32 2}
!1 = !{i32 0, i32 42}