[llvm-commits] [llvm] r171279 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp test/Transforms/InstCombine/store.ll

[Nuno Lopes]

BTW, there is already a function to merge TBAA data from two instructions 
(MDNode::getMostGenericTBAA):
http://llvm.org/docs/doxygen/html/classllvm_1_1MDNode.html#a3c210e8905029a012df3384a7eeb63ad

Nuno

----- Original Message -----
> Author: lattner
> Date: Mon Dec 31 02:10:58 2012
> New Revision: 171279
>
> URL: http://llvm.org/viewvc/llvm-project?rev=171279&view=rev
> Log:
> teach instcombine to preserve TBAA tag when merging two stores, part of
> PR14753
>
> Modified:
>    llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
>    llvm/trunk/test/Transforms/InstCombine/store.ll
>
> Modified: 
> llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
> URL: 
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp?rev=171279&r1=171278&r2=171279&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp 
> (original)
> +++ llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp 
> Mon Dec 31 02:10:58 2012
> @@ -802,6 +802,13 @@
>   InsertNewInstBefore(NewSI, *BBI);
>   NewSI->setDebugLoc(OtherStore->getDebugLoc());
>
> +  // If the two stores had the same TBAA tag, preserve it.
> +  if (MDNode *TBAATag1 = SI.getMetadata(LLVMContext::MD_tbaa))
> +    if (MDNode *TBAATag2 = OtherStore->getMetadata(LLVMContext::MD_tbaa))
> +      if (TBAATag1 == TBAATag2)
> +        NewSI->setMetadata(LLVMContext::MD_tbaa, TBAATag1);
> +
> +
>   // Nuke the old stores.
>   EraseInstFromFunction(SI);
>   EraseInstFromFunction(*OtherStore);
>
> Modified: llvm/trunk/test/Transforms/InstCombine/store.ll
> URL: 
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/store.ll?rev=171279&r1=171278&r2=171279&view=diff
> ==============================================================================
> --- llvm/trunk/test/Transforms/InstCombine/store.ll (original)
> +++ llvm/trunk/test/Transforms/InstCombine/store.ll Mon Dec 31 02:10:58 
> 2012
> @@ -83,3 +83,37 @@
> ; CHECK-NEXT:  ret void
> }
>
> +
> +; PR14753 - merging two stores should preserve the TBAA tag.
> +define void @test6(i32 %n, float* %a, i32* %gi) nounwind uwtable ssp {
> +entry:
> +  store i32 42, i32* %gi, align 4, !tbaa !0
> +  br label %for.cond
> +
> +for.cond:                                         ; preds = %for.body, 
> %entry
> +  %storemerge = phi i32 [ 0, %entry ], [ %inc, %for.body ]
> +  %0 = load i32* %gi, align 4, !tbaa !0
> +  %cmp = icmp slt i32 %0, %n
> +  br i1 %cmp, label %for.body, label %for.end
> +
> +for.body:                                         ; preds = %for.cond
> +  %idxprom = sext i32 %0 to i64
> +  %arrayidx = getelementptr inbounds float* %a, i64 %idxprom
> +  store float 0.000000e+00, float* %arrayidx, align 4, !tbaa !3
> +  %1 = load i32* %gi, align 4, !tbaa !0
> +  %inc = add nsw i32 %1, 1
> +  store i32 %inc, i32* %gi, align 4, !tbaa !0
> +  br label %for.cond
> +
> +for.end:                                          ; preds = %for.cond
> +  ret void
> +; CHECK: @test6
> +; CHECK: for.cond:
> +; CHECK-NEXT: phi i32 [ 42
> +; CHECK-NEXT: store i32 %storemerge, i32* %gi, align 4, !tbaa !0
> +}
> +
> +!0 = metadata !{metadata !"int", metadata !1}
> +!1 = metadata !{metadata !"omnipotent char", metadata !2}
> +!2 = metadata !{metadata !"Simple C/C++ TBAA"}
> +!3 = metadata !{metadata !"float", metadata !1}
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits