[llvm] cbd7eab - Revert "[ConstantFold] Handle vectors in ConstantFoldLoadThroughBitcast()"

[Roman Lebedev via llvm-commits]

Please either provide a reproducer (bug says "Permission denied.") or
revert the revert.

On Wed, Mar 17, 2021 at 12:37 AM Zequan Wu via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
>
>
> Author: Zequan Wu
> Date: 2021-03-16T14:36:21-07:00
> New Revision: cbd7eabea88ea5cb9d6e6c6f43bd2165c8becb36
>
> URL: https://github.com/llvm/llvm-project/commit/cbd7eabea88ea5cb9d6e6c6f43bd2165c8becb36
> DIFF: https://github.com/llvm/llvm-project/commit/cbd7eabea88ea5cb9d6e6c6f43bd2165c8becb36.diff
>
> LOG: Revert "[ConstantFold] Handle vectors in ConstantFoldLoadThroughBitcast()"
>
> That commit caused chromium build to crash: https://bugs.chromium.org/p/chromium/issues/detail?id=1188885
>
> This reverts commit edf7004851519464f86b0f641da4d6c9506decb1.
>
> Added:
>
>
> Modified:
>     llvm/lib/Analysis/ConstantFolding.cpp
>     llvm/test/Transforms/GVN/non-integral-pointers-inseltpoison.ll
>     llvm/test/Transforms/GVN/non-integral-pointers.ll
>
> Removed:
>
>
>
> ################################################################################
> diff  --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
> index 4d7237becbe6..2e2d1e3a4cf2 100644
> --- a/llvm/lib/Analysis/ConstantFolding.cpp
> +++ b/llvm/lib/Analysis/ConstantFolding.cpp
> @@ -387,6 +387,11 @@ Constant *llvm::ConstantFoldLoadThroughBitcast(Constant *C, Type *DestTy,
>          return ConstantExpr::getCast(Cast, C, DestTy);
>      }
>
> +    // If this isn't an aggregate type, there is nothing we can do to drill down
> +    // and find a bitcastable constant.
> +    if (!SrcTy->isAggregateType())
> +      return nullptr;
> +
>      // We're simulating a load through a pointer that was bitcast to point to
>      // a
> diff erent type, so we can try to walk down through the initial
>      // elements of an aggregate to see if some part of the aggregate is
>
> diff  --git a/llvm/test/Transforms/GVN/non-integral-pointers-inseltpoison.ll b/llvm/test/Transforms/GVN/non-integral-pointers-inseltpoison.ll
> index d26003b2c8f2..2aef7620841b 100644
> --- a/llvm/test/Transforms/GVN/non-integral-pointers-inseltpoison.ll
> +++ b/llvm/test/Transforms/GVN/non-integral-pointers-inseltpoison.ll
> @@ -213,12 +213,14 @@ entry:
>    ret i64 addrspace(4)* %ref
>  }
>
> +; TODO: missed optimization
>  define i8 addrspace(4)* @forward_memcopy(i8 addrspace(4)* addrspace(4)* %loc) {
>  ; CHECK-LABEL: @forward_memcopy(
>  ; CHECK-NEXT:  entry:
>  ; CHECK-NEXT:    [[LOC_BC:%.*]] = bitcast i8 addrspace(4)* addrspace(4)* [[LOC:%.*]] to i8 addrspace(4)*
>  ; CHECK-NEXT:    call void @llvm.memcpy.p4i8.p0i8.i64(i8 addrspace(4)* align 4 [[LOC_BC]], i8* bitcast (<4 x i64 addrspace(4)*>* @NonZeroConstant2 to i8*), i64 8, i1 false)
> -; CHECK-NEXT:    ret i8 addrspace(4)* bitcast (i64 addrspace(4)* getelementptr (i64, i64 addrspace(4)* null, i32 3) to i8 addrspace(4)*)
> +; CHECK-NEXT:    [[REF:%.*]] = load i8 addrspace(4)*, i8 addrspace(4)* addrspace(4)* [[LOC]], align 8
> +; CHECK-NEXT:    ret i8 addrspace(4)* [[REF]]
>  ;
>  entry:
>    %loc.bc = bitcast i8 addrspace(4)* addrspace(4)* %loc to i8 addrspace(4)*
>
> diff  --git a/llvm/test/Transforms/GVN/non-integral-pointers.ll b/llvm/test/Transforms/GVN/non-integral-pointers.ll
> index 07d941fdb619..6b9a9171f5f3 100644
> --- a/llvm/test/Transforms/GVN/non-integral-pointers.ll
> +++ b/llvm/test/Transforms/GVN/non-integral-pointers.ll
> @@ -213,12 +213,14 @@ entry:
>    ret i64 addrspace(4)* %ref
>  }
>
> +; TODO: missed optimization
>  define i8 addrspace(4)* @forward_memcopy(i8 addrspace(4)* addrspace(4)* %loc) {
>  ; CHECK-LABEL: @forward_memcopy(
>  ; CHECK-NEXT:  entry:
>  ; CHECK-NEXT:    [[LOC_BC:%.*]] = bitcast i8 addrspace(4)* addrspace(4)* [[LOC:%.*]] to i8 addrspace(4)*
>  ; CHECK-NEXT:    call void @llvm.memcpy.p4i8.p0i8.i64(i8 addrspace(4)* align 4 [[LOC_BC]], i8* bitcast (<4 x i64 addrspace(4)*>* @NonZeroConstant2 to i8*), i64 8, i1 false)
> -; CHECK-NEXT:    ret i8 addrspace(4)* bitcast (i64 addrspace(4)* getelementptr (i64, i64 addrspace(4)* null, i32 3) to i8 addrspace(4)*)
> +; CHECK-NEXT:    [[REF:%.*]] = load i8 addrspace(4)*, i8 addrspace(4)* addrspace(4)* [[LOC]], align 8
> +; CHECK-NEXT:    ret i8 addrspace(4)* [[REF]]
>  ;
>  entry:
>    %loc.bc = bitcast i8 addrspace(4)* addrspace(4)* %loc to i8 addrspace(4)*
>
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits