PR54915 (ssa-forwprop, vec_perm_expr)
Richard Biener
richard.guenther@gmail.com
Mon Oct 15 09:19:00 GMT 2012
On Sat, Oct 13, 2012 at 11:25 AM, Marc Glisse <marc.glisse@inria.fr> wrote:
> On Fri, 12 Oct 2012, Marc Glisse wrote:
>
>> Hello,
>>
>> apparently, in the optimization that recognizes that {v[1],v[0]} is a
>> VEC_PERM_EXPR, I forgot to check that v is a 2-element vector... (not that
>> there aren't things that could be done if v has a different size, just not
>> directly a VEC_PERM_EXPR, and not right now, priority is to fix the bug)
>>
>> Checking that v has the same type as the result seemed like the easiest
>> way, but there are many variations that could be slightly better or worse.
>>
>> bootstrap+testsuite ok.
>>
>> 2012-10-02 Marc Glisse <marc.glisse@inria.fr>
>>
>> PR tree-optimization/54915
>>
>> gcc/
>> * tree-ssa-forwprop.c (simplify_vector_constructor): Check
>> argument's type.
>>
>> gcc/testsuite/
>> * gcc.dg/tree-ssa/pr54915.c: New testcase.
>
>
> This new version, with a slightly relaxed test, seems preferable and also
> passes testing.
Ok.
Thanks,
Richard.
> --
> Marc Glisse
> Index: testsuite/gcc.dg/tree-ssa/pr54915.c
> ===================================================================
> --- testsuite/gcc.dg/tree-ssa/pr54915.c (revision 0)
> +++ testsuite/gcc.dg/tree-ssa/pr54915.c (revision 0)
> @@ -0,0 +1,12 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +typedef double v2df __attribute__ ((__vector_size__ (16)));
> +typedef double v4df __attribute__ ((__vector_size__ (32)));
> +
> +void f (v2df *ret, v4df* xp)
> +{
> + v4df x = *xp;
> + v2df xx = { x[2], x[3] };
> + *ret = xx;
> +}
>
> Property changes on: testsuite/gcc.dg/tree-ssa/pr54915.c
> ___________________________________________________________________
> Added: svn:eol-style
> + native
> Added: svn:keywords
> + Author Date Id Revision URL
>
> Index: tree-ssa-forwprop.c
> ===================================================================
> --- tree-ssa-forwprop.c (revision 192420)
> +++ tree-ssa-forwprop.c (working copy)
> @@ -2833,20 +2833,22 @@ simplify_vector_constructor (gimple_stmt
> ref = TREE_OPERAND (op1, 0);
> if (orig)
> {
> if (ref != orig)
> return false;
> }
> else
> {
> if (TREE_CODE (ref) != SSA_NAME)
> return false;
> + if (!useless_type_conversion_p (type, TREE_TYPE (ref)))
> + return false;
> orig = ref;
> }
> if (TREE_INT_CST_LOW (TREE_OPERAND (op1, 1)) != elem_size)
> return false;
> sel[i] = TREE_INT_CST_LOW (TREE_OPERAND (op1, 2)) / elem_size;
> if (sel[i] != i) maybe_ident = false;
> }
> if (i < nelts)
> return false;
>
>
More information about the Gcc-patches
mailing list