[Bug c/25911] New: ice in vect_recog_dot_prod_pattern

[Bug c/25911] New: ice in vect_recog_dot_prod_pattern

[dcb314 at hotmail dot com]

I just tried to compile package gsl-1.7-2 from Suse Linux with a recent
GNU C compiler version 4.2 snapshot 20060121. 

The compiler snapshot said

/home/dcb/gnu/42-20060121/results/bin/gcc -g -O3 -Wall -fmessage-length=0
-DHAVE_CONFIG_H -I. -I. -I.. -I.. -O2 -g -fmessage-length=0 -D_FORTIFY_SOURCE=2
-O3 -finline-limit=720 --param max-inline-insns-auto=160 -ffast-math
-funroll-loops -fno-strict-aliasing -momit-leaf-frame-pointer -funit-at-a-time
-ftree-vectorize -c bessel_Kn.c  -fPIC -DPIC -o bessel_Kn.o
bessel_Kn.c: In function sel_Kn.c:103: internal compiler error: in
vect_recog_dot_prod_pattern, at tree-vect-patterns.c:246
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

It seems that the flags -O2  -ffast-math -ftree-vectorize are required.

Preprocessed source code attached.


-- 
           Summary: ice in vect_recog_dot_prod_pattern
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dcb314 at hotmail dot com
  GCC host triplet: x86_64-suse-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug c/25911] ice in vect_recog_dot_prod_pattern

[dcb314 at hotmail dot com]

------- Comment #1 from dcb314 at hotmail dot com  2006-01-22 14:05 -------
Created an attachment (id=10703)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10703&action=view)
c source code


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug tree-optimization/25911] [4.2 Regression] ice in vect_recog_dot_prod_pattern

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
          Component|c                           |tree-optimization
           Keywords|                            |ice-on-valid-code
            Summary|ice in                      |[4.2 Regression] ice in
                   |vect_recog_dot_prod_pattern |vect_recog_dot_prod_pattern
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug tree-optimization/25911] [4.2 Regression] ice in vect_recog_dot_prod_pattern

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2006-01-23 18:28 -------
Reducing.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug tree-optimization/25911] [4.2 Regression] ice in vect_recog_dot_prod_pattern

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2006-01-23 18:37 -------
Reduced testcase:
double bessel_Kn_scaled_small_x(int n, double x)
{
  int k;
  double y = 0.25 * x * x;
  double ex = exp(x);
  double k_term;
  double term1, sum1, ln_pre1;
  double term2, sum2, pre2;
  for(k=1; k<=n-1; k++)
  {
    k_term *= -y/(k * (n-k));
    sum1 += k_term;
  }
  term1 = 0.5 * exp(ln_pre1) * sum1;
  return ex * (term1 + term2);
}


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-01-23 18:37:52
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug tree-optimization/25911] [4.2 Regression] ice in vect_recog_dot_prod_pattern

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2006-01-23 18:42 -------
Further reduced:
double bessel_Kn_scaled_small_x(int n)
{
  int k;
  double k_term, sum1;
  for(k=1; k<=n-1; k++)
  {
    k_term *= -1/(k * (n-k));
    sum1 += k_term;
  }
  return sum1;
}


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug tree-optimization/25911] [4.2 Regression] ice in vect_recog_dot_prod_pattern

[dorit at il dot ibm dot com]

------- Comment #5 from dorit at il dot ibm dot com  2006-01-24 09:10 -------
Patch:

Index: tree-vect-patterns.c
===================================================================
--- tree-vect-patterns.c        (revision 109954)
+++ tree-vect-patterns.c        (working copy)
@@ -243,7 +243,8 @@
   gcc_assert (stmt);
   stmt_vinfo = vinfo_for_stmt (stmt);
   gcc_assert (stmt_vinfo);
-  gcc_assert (STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_loop_def);
+  if (STMT_VINFO_DEF_TYPE (stmt_vinfo) != vect_loop_def)
+    return NULL;
   expr = TREE_OPERAND (stmt, 1);
   if (TREE_CODE (expr) != MULT_EXPR)
     return NULL;


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug tree-optimization/25911] [4.2 Regression] ice in vect_recog_dot_prod_pattern

[pinskia at gcc dot gnu dot org]

------- Comment #6 from pinskia at gcc dot gnu dot org  2006-01-24 15:26 -------
Patch posted:
http://gcc.gnu.org/ml/gcc-patches/2006-01/msg01621.html


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2006-
                   |                            |01/msg01621.html
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug tree-optimization/25911] [4.2 Regression] ice in vect_recog_dot_prod_pattern

[dorit at gcc dot gnu dot org]

------- Comment #7 from dorit at gcc dot gnu dot org  2006-01-29 16:50 -------
Subject: Bug 25911

Author: dorit
Date: Sun Jan 29 16:50:05 2006
New Revision: 110377

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=110377
Log:
        PR tree-opt/25911
        * tree-vect-patterns.c (vect_recog_dot_prod_pattern): Change assert
        to an if check.


Added:
    trunk/gcc/testsuite/gcc.dg/vect/fast-math-vect-pr25911.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-patterns.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911

[Bug tree-optimization/25911] [4.2 Regression] ice in vect_recog_dot_prod_pattern

[pinskia at gcc dot gnu dot org]

------- Comment #8 from pinskia at gcc dot gnu dot org  2006-01-29 17:06 -------
Fixed.


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pinskia at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25911