[PATCH] D26060: [ConstantFolding] Don't try to cast vectors to pointer if they have different size

[Davide Italiano via llvm-commits]

davide added a comment.

In https://reviews.llvm.org/D26060#582443, @filcab wrote:

> Using undef in tests can hide some things.
>  Can you tell me what you get with your test case for this?
>
>   %struct.foo = type { [1 x i64] }
>  
>   define <4 x i64*> @patatino3(%struct.foo*) {
>     %2 = getelementptr inbounds %struct.foo, %struct.foo* %0, i32 0,
>                                  i32 0, <4 x i8> zeroinitializer
>     ret <4 x i64*> %2
>   }
>
>
> clang 3.9 gives me this:
>
>   define <4 x i64*> @patatino3(%struct.foo* readnone) local_unnamed_addr #0 {
>     %2 = getelementptr inbounds %struct.foo, %struct.foo* %0, i64 0, i32 0, <4 x i64> zeroinitializer
>     ret <4 x i64*> %2
>   }
>
>
> Where the first i32 and the i8 vector have been cast to i64 and i64 vector.


This is what I get

  [davide at localhost bin]$ ./opt -instcombine filcab.ll -o - -S
  ; ModuleID = 'filcab.ll'
  source_filename = "filcab.ll"
  
  %struct.foo = type { [1 x i64] }
  
  define <4 x i64*> @patatino3(%struct.foo*) {
    %2 = getelementptr inbounds %struct.foo, %struct.foo* %0, i64 0, i32 0, <4 x i64> zeroinitializer
    ret <4 x i64*> %2
  }
  [davide at localhost bin]$ cat filcab.ll
  %struct.foo = type { [1 x i64] }
  
  define <4 x i64*> @patatino3(%struct.foo*) {
    %2 = getelementptr inbounds %struct.foo, %struct.foo* %0, i32 0,
                                 i32 0, <4 x i8> zeroinitializer
    ret <4 x i64*> %2
  }

which I think is what is expected, but another pair of eyes wouldn't hurt


https://reviews.llvm.org/D26060