[Bug target/23831] New: ICE in immed_double_const with vectorized multipication

[Bug target/23831] New: ICE in immed_double_const with vectorized multipication

[uros at kss-loka dot si]

This testcase ICEs with -O2 -msse2 -ftree-vectorize:

void
test_1 (void)
{
  static unsigned int bm[16];
  int j;
  for (j = 0; j < 16; j++)
    bm[j] = bm[j] * 8;
}

prxxx.c: In function 'test_1':
prxxx.c:8: internal compiler error: in immed_double_const, at emit-rtl.c:468

[BTW: This bug was found when dealing with PR target/22480. As a nice 
enhancement, this code should actually be transformed into vector left shift by 
3.]

-- 
           Summary: ICE in immed_double_const with vectorized multipication
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code, ssemmx
          Severity: normal
          Priority: P2
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: uros at kss-loka dot si
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831

[Bug target/23831] [4.1 Regression] ICE in immed_double_const with vectorized multipication

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-12 13:51 -------
Confirmed, works correctly on powerpc-darwin with about the same IR.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
  GCC build triplet|i686-pc-linux-gnu           |
   GCC host triplet|i686-pc-linux-gnu           |
      Known to fail|                            |4.1.0
      Known to work|                            |4.0.0
   Last reconfirmed|0000-00-00 00:00:00         |2005-09-12 13:51:38
               date|                            |
            Summary|ICE in immed_double_const   |[4.1 Regression] ICE in
                   |with vectorized             |immed_double_const with
                   |multipication               |vectorized multipication
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831

[Bug target/23831] [4.1 Regression] ICE in immed_double_const with vectorized multipication

[uros at kss-loka dot si]

------- Additional Comments From uros at kss-loka dot si  2005-09-15 11:53 -------
He problem is in following RTL:

(insn 30 29 31 1 (set (reg:V4SI 75)
        (mem/u/i:V4SI (symbol_ref/u:SI ("*.LC0") [flags 0x2]) [3 S16 A128])) 
541 {*movv4si_internal} (nil)
    (expr_list:REG_EQUAL (const_vector:V4SI [
                (const_int 5 [0x5])
                (const_int 5 [0x5])
                (const_int 5 [0x5])
                (const_int 5 [0x5])
            ])
        (nil)))

...

(insn 33 32 34 1 (set (subreg:TI (reg:V4SI 78) 0)
        (lshiftrt:TI (subreg:TI (reg:V4SI 75) 0)
            (const_int 32 [0x20]))) 709 {sse2_lshrti3} (nil)
    (nil))

Somehow a TImode constant is produced, and it triggers the check below:

      gcc_assert (GET_MODE_CLASS (mode) == MODE_INT
		  || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT
		  /* We can get a 0 for an error mark.  */
		  || GET_MODE_CLASS (mode) == MODE_VECTOR_INT
		  || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT);

      /* We clear out all bits that don't belong in MODE, unless they and
	 our sign bit are all one.  So we get either a reasonable negative
	 value or a reasonable unsigned value for this mode.  */
      width = GET_MODE_BITSIZE (mode);
      if (width < HOST_BITS_PER_WIDE_INT
	  && ((i0 & ((HOST_WIDE_INT) (-1) << (width - 1)))
	      != ((HOST_WIDE_INT) (-1) << (width - 1))))
	i0 &= ((HOST_WIDE_INT) 1 << width) - 1, i1 = 0;
      else if (width == HOST_BITS_PER_WIDE_INT
	       && ! (i1 == ~0 && i0 < 0))
	i1 = 0;
      else
	/* We should be able to represent this value as a constant.  */
>>>	gcc_assert (width <= 2 * HOST_BITS_PER_WIDE_INT);

HOSTS_BITS_PER_WIDE_INT is 32 bit for ia32, and TImode constants are 128 bit 
wide. I don't know the correct solution here. If the assert is commented out, 
the ICE goes away and produced code works as expected.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831

[Bug target/23831] [4.1 Regression] ICE in immed_double_const with vectorized multipication

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-15 14:48 -------
It might be just the time to move x86 over to HWI being 64bit like all other sanse targets, especially 
when it uses 128bit constants.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831

[Bug target/23831] [4.1 Regression] ICE in immed_double_const with vectorized multipication

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-15 14:54 -------
See PR 14981 for another one which was caused by the same issue before.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831

[Bug middle-end/23831] [4.1 Regression] ICE in immed_double_const with vectorized multipication

[uros at kss-loka dot si]

------- Additional Comments From uros at kss-loka dot si  2005-09-26 08:59 -------
This is in fact middle-end problem. Patch at http://gcc.gnu.org/ml/gcc-
patches/2005-09/msg01583.html.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |uros at kss-loka dot si
                   |dot org                     |
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2005-
                   |                            |09/msg01583.html
             Status|NEW                         |ASSIGNED
          Component|target                      |middle-end
           Keywords|                            |patch
   Last reconfirmed|2005-09-12 13:51:38         |2005-09-26 08:59:42
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831

[Bug middle-end/23831] [4.1 Regression] ICE in immed_double_const with vectorized multipication

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-09-26 18:16 -------
Subject: Bug 23831

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	ian@gcc.gnu.org	2005-09-26 18:16:11

Modified files:
	gcc            : ChangeLog simplify-rtx.c 

Log message:
	PR middle-end/23831
	* simplify-rtx.c (simplify_immed_subreg) [MODE_INT]: Skip
	simplification if elem_bitsize > 2 * HOST_BITS_PER_WIDE_INT.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.10024&r2=2.10025
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/simplify-rtx.c.diff?cvsroot=gcc&r1=1.247&r2=1.248



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831

[Bug middle-end/23831] [4.1 Regression] ICE in immed_double_const with vectorized multipication

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-09-26 18:18 -------
Subject: Bug 23831

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	ian@gcc.gnu.org	2005-09-26 18:17:54

Modified files:
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg/vect: pr23831.c 

Log message:
	PR middle-end/23831
	* gcc.dg/vect/pr23831.c: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.6103&r2=1.6104
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/vect/pr23831.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831

[Bug middle-end/23831] [4.1 Regression] ICE in immed_double_const with vectorized multipication

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-26 19:55 -------
Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23831