yggdrasil/gcc
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

re PR tree-optimization/60656 (x86 vectorization produces wrong code)

Browse Source 
2014-04-04  Cong Hou  <congh@google.com>

    PR tree-optimization/60656
    * tree-vect-stmts.c (supportable_widening_operation):
      Fix a bug that elements in a vector with vect_used_by_reduction
      property are incorrectly reordered when the operation on it is not
      consistant with the one in reduction operation.

2014-04-04  Cong Hou  <congh@google.com>

    PR tree-optimization/60656
    * gcc.dg/vect/pr60656.c: New test.

From-SVN: r209138
This commit is contained in:
Cong Hou 2014-04-04 21:27:21 -04:00 committed by Cong Hou
parent 604fb57809
commit ebc047a210
4 changed files with 73 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2014-04-04 Cong Hou <congh@google.com>
PR tree-optimization/60656
* tree-vect-stmts.c (supportable_widening_operation):
Fix a bug that elements in a vector with vect_used_by_reduction
property are incorrectly reordered when the operation on it is not
consistant with the one in reduction operation.
2014-04-04 John David Anglin <danglin@gcc.gnu.org>
PR rtl-optimization/60155

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2014-04-04 Cong Hou <congh@google.com>
PR tree-optimization/60656
* gcc.dg/vect/pr60656.c: New test.
2014-04-04 Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
* gcc.dg/builtin-bswap-6.c: Adjust return value to disable GCC

45
gcc/testsuite/gcc.dg/vect/pr60656.c Normal file
View File

@ -0,0 +1,45 @@
/* { dg-require-effective-target vect_int } */
#include "tree-vect.h"
__attribute__ ((noinline)) long
foo ()
{
int v[] = {5000, 5001, 5002, 5003};
long s = 0;
int i;
for(i = 0; i < 4; ++i)
{
long P = v[i];
s += P*P*P;
}
return s;
}
long
bar ()
{
int v[] = {5000, 5001, 5002, 5003};
long s = 0;
int i;
for(i = 0; i < 4; ++i)
{
long P = v[i];
s += P*P*P;
__asm__ volatile ("");
}
return s;
}
int main()
{
if (foo () != bar ())
abort ();
return 0;
}
/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
/* { dg-final { cleanup-tree-dump "vect" } } */

16
gcc/tree-vect-stmts.c
View File

@ -7848,7 +7848,21 @@ supportable_widening_operation (enum tree_code code, gimple stmt,
stmt, vectype_out, vectype_in,
code1, code2, multi_step_cvt,
interm_types))
return true;
{
/* Elements in a vector with vect_used_by_reduction property cannot
be reordered if the use chain with this property does not have the
same operation. One such an example is s += a * b, where elements
in a and b cannot be reordered. Here we check if the vector defined
by STMT is only directly used in the reduction statement. */
tree lhs = gimple_assign_lhs (stmt);
use_operand_p dummy;
gimple use_stmt;
stmt_vec_info use_stmt_info = NULL;
if (single_imm_use (lhs, &dummy, &use_stmt)
&& (use_stmt_info = vinfo_for_stmt (use_stmt))
&& STMT_VINFO_DEF_TYPE (use_stmt_info) == vect_reduction_def)
return true;
}
c1 = VEC_WIDEN_MULT_LO_EXPR;
c2 = VEC_WIDEN_MULT_HI_EXPR;
break;