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Re: PR54915 (ssa-forwprop, vec_perm_expr)
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.
--
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;