[Bug rtl-optimization/56571] New: ICE in copyprop_hardreg_forward_1, at regcprop.c (insn does not satisfy its constraints !)

[Bug rtl-optimization/56571] New: ICE in copyprop_hardreg_forward_1, at regcprop.c (insn does not satisfy its constraints !)

[antoine.balestrat at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56571

             Bug #: 56571
           Summary: ICE in copyprop_hardreg_forward_1, at regcprop.c (insn
                    does not satisfy its constraints !)
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: antoine.balestrat@gmail.com


Hello !
The following testcase makes GCC 4.7.2 and 4.8.0 as of 20130308 fail.

$ cat insn.c
int a, b;

int f(void)
{
    (a % b) && f();
    a = (0 || a | (a ? : 1));
}

$ xgcc -w -O2 -funroll-loops -ftracer insn.c
insn.c: In function ‘f’:
insn.c:7:1: error: insn does not satisfy its constraints:
 }
 ^
(insn 83 79 84 9 (parallel [
            (set (reg:CCZ 17 flags)
                (compare:CCZ (ior:SI (reg:SI 4 si [81])
                        (reg:SI 2 cx [orig:69 D.1741 ] [69]))
                    (const_int 0 [0])))
            (clobber (reg:SI 39 r10 [81]))
        ]) insn.c:6 451 {*iorsi_3}
     (expr_list:REG_DEAD (reg:SI 2 cx [orig:69 D.1741 ] [69])
        (expr_list:REG_DEAD (reg:SI 0 ax [81])
            (expr_list:REG_UNUSED (reg:SI 0 ax [81])
                (nil)))))
insn.c:7:1: internal compiler error: in copyprop_hardreg_forward_1, at
regcprop.c:774
0x8a175a _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
    ../../srcdir/gcc/rtl-error.c:109
0x8a177f _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
    ../../srcdir/gcc/rtl-error.c:120
0x87b1e7 copyprop_hardreg_forward_1
    ../../srcdir/gcc/regcprop.c:774
0x87b1e7 copyprop_hardreg_forward
    ../../srcdir/gcc/regcprop.c:1085
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

[Bug rtl-optimization/56571] [4.7/4.8 Regression] ICE in copyprop_hardreg_forward_1, at regcprop.c (insn does not satisfy its constraints !)

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56571

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |x86_64-*-*
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-03-08
      Known to work|                            |4.6.4
   Target Milestone|---                         |4.7.3
            Summary|ICE in                      |[4.7/4.8 Regression] ICE in
                   |copyprop_hardreg_forward_1, |copyprop_hardreg_forward_1,
                   |at regcprop.c (insn does    |at regcprop.c (insn does
                   |not satisfy its constraints |not satisfy its constraints
                   |!)                          |!)
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> 2013-03-08 11:24:42 UTC ---
Confirmed.

[Bug rtl-optimization/56571] [4.7/4.8 Regression] ICE in copyprop_hardreg_forward_1, at regcprop.c (insn does not satisfy its constraints !)

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56571

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-03-08 12:08:53 UTC ---
Started with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181188

[Bug rtl-optimization/56571] [4.7/4.8 Regression] ICE in copyprop_hardreg_forward_1, at regcprop.c (insn does not satisfy its constraints !)

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56571

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bernds at gcc dot gnu.org,
                   |                            |jakub at gcc dot gnu.org,
                   |                            |steven at gcc dot gnu.org

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-03-08 14:49:10 UTC ---
Sounds like regrename.c bug.  This pass changes:
83: {flags:CCZ=cmp(ax:SI|cx:SI,0);clobber ax:SI;}
instruction (iorsi_3) into:
83: {flags:CCZ=cmp(si:SI|cx:SI,0);clobber r10:SI;}
which of course doesn't work, the pattern has "=r" constraint on the clobber,
and "%0" and "rme" constraints on the comparison operands, so it requires that
the clobber matches one of the registers.
I'm quite surprised not to see any validate_change calls in the whole
regrename.c, how does it ensure that what it changes is actually valid?

[Bug rtl-optimization/56571] [4.7/4.8 Regression] ICE in copyprop_hardreg_forward_1, at regcprop.c (insn does not satisfy its constraints !)

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56571

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-03-08 16:06:33 UTC ---
Ok, it seems to be caused by rtl sharing of the clobber, which has been
introduced by Honza: http://gcc.gnu.org/ml/gcc-patches/2004-01/msg01918.html
Honza is going to try sharing only clobbers of hard regs that don't have
ORIGINAL_REGNO set on them and disallow sharing anything else (plus copy it on
copy_rtx etc.).

[Bug rtl-optimization/56571] [4.7/4.8 Regression] ICE in copyprop_hardreg_forward_1, at regcprop.c (insn does not satisfy its constraints !)

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56571

--- Comment #5 from Jan Hubicka <hubicka at gcc dot gnu.org> 2013-03-12 12:13:44 UTC ---
Author: hubicka
Date: Tue Mar 12 12:13:33 2013
New Revision: 196612

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=196612
Log:
    PR middle-end/56571
    * valtrack.c (cleanup_auto_inc_dec): Unshare clobbers originating
    from pseudos.
    * emit-rtl.c (verify_rtx_sharing): Likewise.
    (copy_insn_1): Likewise.
    * rtl.c (copy_rtx): Likewise.
    PR middle-end/56571
    * gcc.c-torture/compile/pr56571.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr56571.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/emit-rtl.c
    trunk/gcc/rtl.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/valtrack.c

[Bug rtl-optimization/56571] [4.7/4.8 Regression] ICE in copyprop_hardreg_forward_1, at regcprop.c (insn does not satisfy its constraints !)

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56571

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |hubicka at gcc dot gnu.org
         Resolution|                            |FIXED

--- Comment #6 from Jan Hubicka <hubicka at gcc dot gnu.org> 2013-03-12 12:15:16 UTC ---
Fixed.