Re: [C++] Fix __builtin_shuffle

[Jakub Jelinek <jakub@redhat.com>]

Hi!

On Thu, Jun 27, 2013 at 01:59:37PM +0200, Marc Glisse wrote:
> --- testsuite/g++.dg/ext/pr57509.C	(revision 0)
> +++ testsuite/g++.dg/ext/pr57509.C	(revision 0)
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-options "-std=c++11" } */
> +
> +template <bool> struct enable_if {};
> +template <> struct enable_if<true> {typedef void type;};
> +template <class T> void f (T& v) { v = __builtin_shuffle (v, v); }
> +template <class T> void g (T) {}
> +template <class T> auto g (T x) -> typename enable_if<sizeof(__builtin_shuffle(x,x))!=2>::type {}
> +typedef int v4i __attribute__((vector_size(4*sizeof(int))));
> +typedef float v4f __attribute__((vector_size(4*sizeof(float))));
> +int main(){
> +  v4i a = {1,2,3,0};
> +  f(a);
> +  v4f b = {1,2,3,0};
> +  g(b);
> +}

Note this testcase fails on i686-linux:
/usr/src/gcc/gcc/testsuite/g++.dg/ext/pr57509.C: In function 'int main()':
/usr/src/gcc/gcc/testsuite/g++.dg/ext/pr57509.C:15:7: warning: SSE vector argument without SSE enabled changes the ABI [enabled by default]
/usr/src/gcc/gcc/testsuite/g++.dg/ext/pr57509.C:15:7: warning: SSE vector argument without SSE enabled changes the ABI [enabled by default]
/usr/src/gcc/gcc/testsuite/g++.dg/ext/pr57509.C:15:7: note: The ABI for passing parameters with 16-byte alignment has changed in GCC 4.6

The note is actually pruned, but the warnings aren't.  -Wno-abi -Wno-psabi
doesn't help, but -w does, so I'd suggest just to add -w to dg-options.

	Jakub