llvm/test/Transforms/IndVarSimplify/2011-09-10-widen-nsw.ll
Zinovy Nis 31713943aa [BUG][INDVAR] Fix for PR21014: wrong SCEV operands commuting for non-commutative instructions
My commit rL216160 introduced a bug PR21014: IndVars widens code 'for (i = ; i < ...; i++) arr[ CONST - i]' into 'for (i = ; i < ...; i++) arr[ i - CONST]'
thus inverting index expression. This patch fixes it. 
Thanks to Jörg Sonnenberger for pointing.

Differential Revision: http://reviews.llvm.org/D5576



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218867 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-02 13:01:15 +00:00

44 lines
1.5 KiB
LLVM

; RUN: opt < %s -indvars -S | FileCheck %s
; Test WidenIV::GetExtendedOperandRecurrence.
; %add, %sub and %mul should be extended to i64 because it is nsw, even though its
; sext cannot be hoisted outside the loop.
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
define void @test() nounwind {
entry:
br i1 undef, label %for.body11, label %for.end285
for.body11: ; preds = %entry
%shl = shl i32 1, 1
%shl132 = shl i32 %shl, 1
br label %for.body153
for.body153: ; preds = %for.body153, %for.body11
br i1 undef, label %for.body170, label %for.body153
; CHECK: add nsw i64 %indvars.iv, 1
; CHECK: sub nsw i64 %indvars.iv, 2
; CHECK: sub nsw i64 4, %indvars.iv
; CHECK: mul nsw i64 %indvars.iv, 8
for.body170: ; preds = %for.body170, %for.body153
%i2.19 = phi i32 [ %add249, %for.body170 ], [ 0, %for.body153 ]
%add = add nsw i32 %i2.19, 1
%add.idxprom = sext i32 %add to i64
%sub = sub nsw i32 %i2.19, 2
%sub.idxprom = sext i32 %sub to i64
%sub.neg = sub nsw i32 4, %i2.19
%sub.neg.idxprom = sext i32 %sub.neg to i64
%mul = mul nsw i32 %i2.19, 8
%mul.idxprom = sext i32 %mul to i64
%add249 = add nsw i32 %i2.19, %shl132
br label %for.body170
for.end285: ; preds = %entry
ret void
}