[llvm-commits] [llvm] r155809 - in /llvm/trunk: lib/Transforms/Scalar/LoopStrengthReduce.cpp test/Transforms/LoopStrengthReduce/pr12691.ll

[Evan Cheng]

I agree. Bill?

Evan

On Apr 29, 2012, at 9:10 PM, Rafael Espíndola wrote:

> This was a regression from 3.0, we might want to include this patch in 3.1.
> 
> On 29 April 2012 23:53, Rafael Espindola <rafael.espindola at gmail.com> wrote:
>> Author: rafael
>> Date: Sun Apr 29 22:53:06 2012
>> New Revision: 155809
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=155809&view=rev
>> Log:
>> Make sure HoistInsertPosition finds a position that is dominated by all
>> inputs.
>> 
>> Added:
>>    llvm/trunk/test/Transforms/LoopStrengthReduce/pr12691.ll
>> Modified:
>>    llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
>> 
>> Modified: llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp?rev=155809&r1=155808&r2=155809&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp (original)
>> +++ llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp Sun Apr 29 22:53:06 2012
>> @@ -4140,7 +4140,7 @@
>>       // Attempt to find an insert position in the middle of the block,
>>       // instead of at the end, so that it can be used for other expansions.
>>       if (IDom == Inst->getParent() &&
>> -          (!BetterPos || DT.dominates(BetterPos, Inst)))
>> +          (!BetterPos || !DT.dominates(Inst, BetterPos)))
>>         BetterPos = llvm::next(BasicBlock::iterator(Inst));
>>     }
>>     if (!AllDominate)
>> 
>> Added: llvm/trunk/test/Transforms/LoopStrengthReduce/pr12691.ll
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopStrengthReduce/pr12691.ll?rev=155809&view=auto
>> ==============================================================================
>> --- llvm/trunk/test/Transforms/LoopStrengthReduce/pr12691.ll (added)
>> +++ llvm/trunk/test/Transforms/LoopStrengthReduce/pr12691.ll Sun Apr 29 22:53:06 2012
>> @@ -0,0 +1,34 @@
>> +; RUN: opt < %s -loop-reduce -S | FileCheck %s
>> +
>> + at d = common global i32 0, align 4
>> +
>> +define void @fn2(i32 %x) nounwind uwtable {
>> +entry:
>> +  br label %for.cond
>> +
>> +for.cond:
>> +  %g.0 = phi i32 [ 0, %entry ], [ %dec, %for.cond ]
>> +  %tobool = icmp eq i32 %x, 0
>> +  %dec = add nsw i32 %g.0, -1
>> +  br i1 %tobool, label %for.cond, label %for.end
>> +
>> +for.end:
>> +; CHECK:  %tmp1 = load i32* @d, align 4
>> +; CHECK-NEXT:  %tmp2 = load i32* @d, align 4
>> +; CHECK-NEXT:  %0 = sub i32 %tmp1, %tmp2
>> +
>> +  %tmp1 = load i32* @d, align 4
>> +  %add = add nsw i32 %tmp1, %g.0
>> +  %tmp2 = load i32* @d, align 4
>> +  %tobool26 = icmp eq i32 %x, 0
>> +  br i1 %tobool26, label %for.end5, label %for.body.lr.ph
>> +
>> +for.body.lr.ph:
>> +  %tobool3 = icmp ne i32 %tmp2, %add
>> +  br label %for.end5
>> +
>> +for.end5:
>> +  ret void
>> +}
>> +
>> +
> 
> 
> Cheers,
> Rafael
> 
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