[Bug tree-optimization/43430] New: Missed vectorization: "stmt not supported: cond_expr"

[Bug tree-optimization/43430] New: Missed vectorization: "stmt not supported: cond_expr"

[spop at gcc dot gnu dot org]

This code from FFmpeg is not vectorized:

gcc-4.5 -c vsad_intra.c -O3 -ffast-math -ftree-vectorizer-verbose=7 -msse2
[...]
vsad_intra.c:15: note: not vectorized: relevant stmt not supported: iftmp.0_7 =
[cond_expr] iftmp.0_35 < 0 ? iftmp.0_77 : iftmp.0_35;


typedef short DCTELEM;
typedef unsigned char uint8_t;
typedef long int x86_reg;
typedef unsigned int uint32_t;
typedef unsigned long int uint64_t;

int
vsad16_c (void *c, uint8_t * s1, uint8_t * s2, int stride, int h)
{
  int score = 0;
  int x, y;

  for (y = 1; y < h; y++)
    {
      for (x = 0; x < 16; x++)
        {
          score +=
            ((s1[x] - s2[x] - s1[x + stride] + s2[x + stride]) >=
             0 ? (s1[x] - s2[x] - s1[x + stride] +
                  s2[x + stride]) : (-(s1[x] - s2[x] - s1[x + stride] +
                                       s2[x + stride])));
        }
      s1 += stride;
      s2 += stride;
    }

  return score;
}


-- 
           Summary: Missed vectorization: "stmt not supported: cond_expr"
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: spop at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[spop at gcc dot gnu dot org]

------- Comment #1 from spop at gcc dot gnu dot org  2010-03-26 20:08 -------
Due to the "FORNOW" fail in vectorizable_condition:

  int nunits = TYPE_VECTOR_SUBPARTS (vectype);
  int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
  if (ncopies > 1)
    return false; /* FORNOW */


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[spop at gcc dot gnu dot org]

------- Comment #2 from spop at gcc dot gnu dot org  2010-03-26 20:13 -------
Reduced testcase, for which ncopies is 4.

typedef unsigned char uint8_t;
vsad16_c (void *c, uint8_t * s1, uint8_t * s2, int stride, int h)
{
  int score = 0;
  int x, y;
  for (x = 0; x < 16; x++)
    score += ((s1[x] - s1[x + stride] + s2[x + stride]) >= 0 ?
              s1[x] + s2[x + stride] :
              s2[x + stride]);
  return score;
}


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[spop at gcc dot gnu dot org]

------- Comment #3 from spop at gcc dot gnu dot org  2010-03-26 20:26 -------
vectorizable_condition has to be cleaned up of this condition:

  /* We do not handle two different vector types for the condition
     and the values.  */
  if (TREE_TYPE (TREE_OPERAND (cond_expr, 0)) != TREE_TYPE (vectype))
    return false;

When using: 

typedef int uint8_t;
vsad16_c (void *c, uint8_t * s1, uint8_t * s2, int stride, int h)
{
  int score = 0;
  int x, y;
  for (x = 0; x < 16; x++)
    score += ((s1[x] - s1[x + stride] + s2[x + stride]) >= 0 ?
              s1[x] + s2[x + stride] :
              s2[x + stride]);
  return score;
}

ncopies is then equal to 1, but then this condition is true:
"uint8_t" is a different type than "int"

    type <integer_type 0x7ffff5a91498 uint8_t sizes-gimplified public SI
    type <integer_type 0x7ffff7e7f498 int sizes-gimplified public SI

but using this version, we pass over this condition:

int vsad16_c (void *c, int * s1, int * s2, int stride, int h)
{
  int score = 0;
  int x, y;
  for (x = 0; x < 16; x++)
    score += ((s1[x] - s1[x + stride] + s2[x + stride]) >= 0 ?
              s1[x] + s2[x + stride] :
              s2[x + stride]);
  return score;
}

and the loop is vectorized.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[spop at gcc dot gnu dot org]

------- Comment #4 from spop at gcc dot gnu dot org  2010-03-26 20:49 -------
This cleanup of vectorizable_condition allows this testcase to be vectorized:

typedef int uint8_t;
vsad16_c (void *c, uint8_t * s1, uint8_t * s2, int stride, int h)
{
  int score = 0;
  int x, y;
  for (x = 0; x < 16; x++)
    score += ((s1[x] - s1[x + stride] + s2[x + stride]) >= 0 ?
              s1[x] + s2[x + stride] :
              s2[x + stride]);
  return score;
}


diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 4bce61a..cfb1471 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -3865,7 +3865,8 @@ vectorizable_condition (gimple stmt, gimple_stmt_iterator
*gsi,

   /* We do not handle two different vector types for the condition
      and the values.  */
-  if (TREE_TYPE (TREE_OPERAND (cond_expr, 0)) != TREE_TYPE (vectype))
+  if (!useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (cond_expr, 0)),
+                                 TREE_TYPE (vectype)))
     return false;

   if (TREE_CODE (then_clause) == SSA_NAME)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[spop at gcc dot gnu dot org]

------- Comment #5 from spop at gcc dot gnu dot org  2010-03-26 21:18 -------
Created an attachment (id=20218)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20218&action=view)
Cleanup comparisons of types

This patch replaces with types_compatible_p all the places in the
vectorizer that were comparing types by pointer equality.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[spop at gcc dot gnu dot org]

------- Comment #6 from spop at gcc dot gnu dot org  2010-03-30 19:58 -------
Subject: Bug 43430

Author: spop
Date: Tue Mar 30 19:58:35 2010
New Revision: 157833

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=157833
Log:
Replace type != type comparisons with types_compatible_p.

2010-03-30  Sebastian Pop  <sebastian.pop@amd.com>

        PR middle-end/43430
        * tree-vect-slp.c (vect_get_and_check_slp_defs): Replace type
        pointer comparisons with types_compatible_p.
        * tree-vect-stmts.c (vectorizable_call): Same.
        (vectorizable_condition): Same.

        * gcc.dg/vect/pr43430-1.c: New.

Added:
    trunk/gcc/testsuite/gcc.dg/vect/pr43430-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-slp.c
    trunk/gcc/tree-vect-stmts.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[matz at gcc dot gnu dot org]

------- Comment #7 from matz at gcc dot gnu dot org  2010-09-07 13:24 -------
The remaining problem is the support for ncopies > 1 in
vectorizable_condition. http://gcc.gnu.org/ml/gcc-patches/2010-09/msg00550.html
implements this.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[matz at gcc dot gnu dot org]

------- Comment #8 from matz at gcc dot gnu dot org  2010-09-08 12:40 -------
Subject: Bug 43430

Author: matz
Date: Wed Sep  8 12:40:24 2010
New Revision: 163999

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=163999
Log:
        PR tree-optimization/43430
        * tree-vect-stmts.c (vectorizable_condition): Support multiple
        copies for conditional statements if it's not part of a reduction.

testsuite/
        PR tree-optimization/43430
        * gcc.dg/vect/pr43430-2.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/vect/pr43430-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-stmts.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

[Bug tree-optimization/43430] Missed vectorization: "stmt not supported: cond_expr"

[spop at gcc dot gnu dot org]

------- Comment #9 from spop at gcc dot gnu dot org  2010-09-17 19:01 -------
Fixed.


-- 

spop at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430