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

[Rafael Espíndola]

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