Bug 33597

Created attachment 14269 [details]
rgb2rgb.s produced with -save-temps

The .i file is important and not the .s file.

Created attachment 14270 [details]
Corresponding *.i file

segfaults with -ftree-vectorize in SLP.

reduced testcase:

--cut here--
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;

void
rgb15to24_C (const uint8_t * src, uint8_t * dst, long src_size)
{
  const uint16_t *end;
  const uint16_t *s = (uint16_t *)src;
  uint8_t *d = (uint8_t *)dst;

  end = s + src_size/2;
  while (s < end)
    {
      uint16_t bgr = *s++;

      *d++ = (bgr&0x1F)<<3;
      *d++ = (bgr&0x3E0)>>2;
      *d++ = (bgr&0x7C00)>>7;
    }
}
--cut here--

gcc -O2 -ftree-vectorize -msse2:

t.c: In function �rgb15to24_C�:
t.c:6: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Program received signal SIGSEGV, Segmentation fault.
0x0000000000a94d24 in vect_build_slp_tree (loop_vinfo=0x1039cc0, 
    node=0x7fffb8b97da0, group_size=3, slp_impossible=0x7fffb8b97e3f "", 
    inside_cost=0x7fffb8b97e38, outside_cost=0x7fffb8b97e34, 
    ncopies_for_cost=3) at ../../gcc-svn/trunk/gcc/tree-vect-analyze.c:2700
2700                  if (!VECTOR_MODE_P (optab_op2_mode))


#0  0x0000000000a94d24 in vect_build_slp_tree (loop_vinfo=0x1039cc0, 
    node=0x7fffb8b97da0, group_size=3, slp_impossible=0x7fffb8b97e3f "", 
    inside_cost=0x7fffb8b97e38, outside_cost=0x7fffb8b97e34, 
    ncopies_for_cost=3) at ../../gcc-svn/trunk/gcc/tree-vect-analyze.c:2700
#1  0x0000000000a94f73 in vect_build_slp_tree (loop_vinfo=0x1039cc0, 
    node=0x7fffb8b97e28, group_size=3, slp_impossible=0x7fffb8b97e3f "", 
    inside_cost=0x7fffb8b97e38, outside_cost=0x7fffb8b97e34, 
    ncopies_for_cost=3) at ../../gcc-svn/trunk/gcc/tree-vect-analyze.c:2870
#2  0x0000000000a955e3 in vect_analyze_slp_instance (loop_vinfo=0x1039cc0, 
    stmt=<value optimized out>)
    at ../../gcc-svn/trunk/gcc/tree-vect-analyze.c:3000
#3  0x0000000000a993e0 in vect_analyze_loop (loop=<value optimized out>)
    at ../../gcc-svn/trunk/gcc/tree-vect-analyze.c:3045
#4  0x00000000007f82ce in vectorize_loops ()
    at ../../gcc-svn/trunk/gcc/tree-vectorizer.c:2501

Confirmed on x86_64 and i686/sse2.

Patch in testing:

--cut here--
Index: tree-vect-analyze.c
===================================================================
--- tree-vect-analyze.c (revision 128890)
+++ tree-vect-analyze.c (working copy)
@@ -2696,6 +2696,13 @@
                  return false;
                }
              icode = (int) optab->handlers[(int) vec_mode].insn_code;
+             if (icode == CODE_FOR_nothing)
+               {
+                 if (vect_print_dump_info (REPORT_SLP))
+                   fprintf (vect_dump,
+                            "Build SLP failed: op not supported by target.");
+                 return false;
+               }
              optab_op2_mode = insn_data[icode].operand[2].mode;
              if (!VECTOR_MODE_P (optab_op2_mode))
                {
--cut here--

(In reply to comment #5)
> Patch in testing:

Thanks for fixing this! 
(I've just started to test the exact same patch :))

Ira

Fix summary , swcale -> swscale . Thanks for the fast fix!

Subject: Bug 33597

Author: uros
Date: Sun Sep 30 12:45:32 2007
New Revision: 128891

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=128891
Log:
        PR tree-optimization/33597
        * tree-vect-analyze.c (vect_build_slp_tree): Check if optab handler
        for LSHIFT_EXPR and RSHIFT_EXPR is available for vec_mode.

testsuite/ChangeLog:

        PR tree-optimization/33597
        * gcc.dg/vect/pr33597.c: New testcase.


Added:
    trunk/gcc/testsuite/gcc.dg/vect/pr33597.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-analyze.c

Fixed.