[Bug c/39779] New: ICE shifting byte to the right with constant > 7FFFFFFF

[Bug c/39779] New: ICE shifting byte to the right with constant > 7FFFFFFF

[bjoern at hoehrmann dot de]

% gcc --version
gcc (Debian 4.3.3-7) 4.3.3
Copyright (C) 2008 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

% cat gcc4-bug.c
#include <stdint.h>
int main(void) { 
  uint8_t v1 = 0;
  v1>>=0xdebecced;
}

% gcc gcc4-bug.c
gcc4-bug.c: In function 'main':
gcc4-bug.c:5: warning: right shift count >= width of type
gcc4-bug.c:6: error: unrecognizable insn:
(insn 7 6 8 3 gcc4-bug.c:5 (set (reg:QI 60)
        (const_int -557921043 [0xffffffffdebecced])) -1 (nil))
gcc4-bug.c:6: internal compiler error: in extract_insn, at recog.c:2001
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.3/README.Bugs> for instructions.


-- 
           Summary: ICE shifting byte to the right with constant > 7FFFFFFF
           Product: gcc
           Version: 4.3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bjoern at hoehrmann dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug target/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[ubizjak at gmail dot com]

------- Comment #1 from ubizjak at gmail dot com  2009-04-16 08:28 -------
Confirmed also on i686-pc-linux-gnu.


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
 GCC target triplet|                            |i686-pc-linux-gnu
      Known to fail|                            |4.4.0 4.5.0
   Last reconfirmed|0000-00-00 00:00:00         |2009-04-16 08:28:47
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[ubizjak at gmail dot com]

------- Comment #2 from ubizjak at gmail dot com  2009-04-16 11:37 -------
It looks that convert_modes has some issues. When expanding shift RTX,
convert_modes is called from

#0  convert_modes (mode=QImode, oldmode=QImode, x=0xb7d05fe8, unsignedp=0) at
../../gcc-svn/trunk/gcc/expr.c:769
#1  0x083455ec in expand_binop_directly (mode=USQmode, binoptab=0x8a02148,
op0=<value optimized out>, op1=0xb7d05fe8, target=0xb7d2a2d0, unsignedp=<value
optimized out>, methods=OPTAB_DIRECT, last=0xb7c8f72c) at
../../gcc-svn/trunk/gcc/optabs.c:1488
#2  0x08343389 in expand_binop (mode=QImode, binoptab=0x8a02148,
op0=0xb7d2a2e8, op1=0xb7d05fe8, target=0xb7d2a2d0, unsignedp=0,
methods=OPTAB_DIRECT) at ../../gcc-svn/trunk/gcc/optabs.c:1601
#3  0x08209c95 in expand_shift (code=RSHIFT_EXPR, mode=QImode,
shifted=0xb7d2a2e8, amount=0xb7d29ec4, target=0xb7d2a2d0, unsignedp=0) at
../../gcc-svn/trunk/gcc/expmed.c:2244

as:

convert_modes (mode=QImode, oldmode=QImode, x=0xb7d05fe8, unsignedp=0) at
../../gcc-svn/trunk/gcc/expr.c:769
(gdb) p debug_rtx (x)
(const_int -557921043 [0xdebecced])

We immediatelly hit:

  if (mode == oldmode)
    return x;

so, we return "(const_int -557921043 [0xdebecced])" that doesn't satisfy QImode
constraint. The compilation goes downhill from there...

This looks like generic RTL optimization problem.


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |rtl-optimization


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[ubizjak at gmail dot com]

------- Comment #3 from ubizjak at gmail dot com  2009-04-16 12:26 -------
This testcase fails for all optimization levels:

--cut here--
/* { dg-do compile } */
/* { dg-options "-w" } */

int test (char v1)
{
  v1 >>= 0xdebecced;
  return v1;
}
--cut here--

Follwing patch fixes the failure, but introduces several testsuite failures:

--cut here--
Index: optabs.c
===================================================================
--- optabs.c    (revision 146146)
+++ optabs.c    (working copy)
@@ -1478,18 +1478,10 @@ expand_binop_directly (enum machine_mode
      for their mode.  */

   if (GET_MODE (xop0) != mode0 && mode0 != VOIDmode)
-    xop0 = convert_modes (mode0,
-                         GET_MODE (xop0) != VOIDmode
-                         ? GET_MODE (xop0)
-                         : mode,
-                         xop0, unsignedp);
+    xop0 = convert_modes (mode0, GET_MODE (xop0), xop0, unsignedp);

   if (GET_MODE (xop1) != mode1 && mode1 != VOIDmode)
-    xop1 = convert_modes (mode1,
-                         GET_MODE (xop1) != VOIDmode
-                         ? GET_MODE (xop1)
-                         : mode,
-                         xop1, unsignedp);
+    xop1 = convert_modes (mode1, GET_MODE (xop1), xop1, unsignedp);

   /* If operation is commutative,
      try to make the first operand a register.
--cut here--


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[ubizjak at gmail dot com]

------- Comment #4 from ubizjak at gmail dot com  2009-09-08 15:04 -------
I have (different) patch.


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |ubizjak at gmail dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2009-04-16 08:28:47         |2009-09-08 15:04:46
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[uros at gcc dot gnu dot org]

------- Comment #5 from uros at gcc dot gnu dot org  2009-09-09 19:25 -------
Subject: Bug 39779

Author: uros
Date: Wed Sep  9 19:25:31 2009
New Revision: 151573

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=151573
Log:
        PR rtl-optimization/39779
        * expr.c (convert_modes): Return when mode == oldmode after
        CONST_INTs are processed.

testsuite/ChangeLog:

        PR rtl-optimization/39779
        * gcc.dg/pr39979.c: New test.


Added:
    trunk/gcc/testsuite/gcc.dg/pr39779.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/expr.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[uros at gcc dot gnu dot org]

------- Comment #6 from uros at gcc dot gnu dot org  2009-09-10 15:15 -------
Subject: Bug 39779

Author: uros
Date: Thu Sep 10 15:14:39 2009
New Revision: 151596

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=151596
Log:
        Revert:
        2009-09-09  Uros Bizjak  <ubizjak@gmail.com>

        PR rtl-optimization/39779
        * expr.c (convert_modes): Return when mode == oldmode after
        CONST_INTs are processed.

testsuite/ChangeLog:

        Revert:
        2009-09-09  Uros Bizjak <ubizjak@gmail.com>

        PR rtl-optimization/39779
        * gcc.dg/pr39979.c: New test.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/expr.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[ubizjak at gmail dot com]

-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|ubizjak at gmail dot com    |unassigned at gcc dot gnu
                   |                            |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[howarth at nitro dot med dot uc dot edu]

------- Comment #7 from howarth at nitro dot med dot uc dot edu  2009-09-11 09:54 -------
The pr39779.c test case is ICEing the compiler in gcc trunk on
x86_64-apple-darwin10 at r151625 as follows...

Executing on host:
/sw/src/fink.build/gcc45-4.4.999-20090910/darwin_objdir/gcc/xgcc
-B/sw/src/fink.build/gcc45-4.4.999-20090910/darwin_objdir/gcc/
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c
  -w -S  -o pr39779.s    (timeout = 300)
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:
In function 'test':
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:8:1:
error: unrecognizable insn:
(insn 7 6 8 3
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:6
(set (reg:QI 61)
        (const_int -557921043 [0xffffffffdebecced])) -1 (nil))
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:8:1:
internal compiler error: in extract_insn, at recog.c:2093
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
compiler exited with status 1
output is:
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:
In function 'test':
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:8:1:
error: unrecognizable insn:
(insn 7 6 8 3
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:6
(set (reg:QI 61)
        (const_int -557921043 [0xffffffffdebecced])) -1 (nil))
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:8:1:
internal compiler error: in extract_insn, at recog.c:2093
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

FAIL: gcc.dg/pr39779.c (internal compiler error)
FAIL: gcc.dg/pr39779.c (test for excess errors)
Excess errors:
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:8:1:
error: unrecognizable insn:
(insn 7 6 8 3
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:6
(set (reg:QI 61)
        (const_int -557921043 [0xffffffffdebecced])) -1 (nil))
/sw/src/fink.build/gcc45-4.4.999-20090910/gcc-4.5-20090910/gcc/testsuite/gcc.dg/pr39779.c:8:1:
internal compiler error: in extract_insn, at recog.c:2093


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[howarth at nitro dot med dot uc dot edu]

------- Comment #8 from howarth at nitro dot med dot uc dot edu  2009-09-11 09:55 -------
Using built-in specs.
Target: x86_64-apple-darwin10
Configured with: ../gcc-4.5-20090910/configure --prefix=/sw
--prefix=/sw/lib/gcc4.5 --mandir=/sw/share/man --infodir=/sw/share/info
--enable-languages=c,c++,fortran,objc,java --with-gmp=/sw
--with-libiconv-prefix=/sw --with-ppl=/sw --with-cloog=/sw --with-system-zlib
--x-includes=/usr/X11R6/include --x-libraries=/usr/X11R6/lib
--disable-libjava-multilib --build=x86_64-apple-darwin10
--host=x86_64-apple-darwin10 --target=x86_64-apple-darwin10
Thread model: posix
gcc version 4.5.0 20090911 (experimental) (GCC) 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[jakub at gcc dot gnu dot org]

------- Comment #9 from jakub at gcc dot gnu dot org  2009-09-11 10:45 -------
That's because Uros didn't actually revert the testcase together with the
reversion of the patch (only testsuite/ChangeLog says so).


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |uros at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[ubizjak at gmail dot com]

------- Comment #10 from ubizjak at gmail dot com  2009-09-11 11:22 -------
(In reply to comment #9)
> That's because Uros didn't actually revert the testcase together with the
> reversion of the patch (only testsuite/ChangeLog says so).

Eh, done now.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[ubizjak at gmail dot com]

------- Comment #11 from ubizjak at gmail dot com  2009-09-21 13:02 -------
Another week, another patch in testing:

Index: c-typeck.c
===================================================================
--- c-typeck.c  (revision 151915)
+++ c-typeck.c  (working copy)
@@ -9465,6 +9465,7 @@ build_binary_op (location_t location, en
            unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));

          if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
+             && int_fits_type_p (op1, TREE_TYPE (arg0))
              /* We can shorten only if the shift count is less than the
                 number of bits in the smaller type size.  */
              && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[uros at gcc dot gnu dot org]

------- Comment #12 from uros at gcc dot gnu dot org  2009-09-23 06:44 -------
Subject: Bug 39779

Author: uros
Date: Wed Sep 23 06:43:56 2009
New Revision: 152058

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=152058
Log:
        PR c/39779
        * c-typeck.c (build_binary_op) <short_shift>: Check that integer
        constant is more than zero.

testsuite/ChangeLog:

        PR c/39779
        * gcc.c-torture/compile/pr39779.c: New test.


Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr39779.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-typeck.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[uros at gcc dot gnu dot org]

------- Comment #13 from uros at gcc dot gnu dot org  2009-09-23 09:37 -------
Subject: Bug 39779

Author: uros
Date: Wed Sep 23 09:37:25 2009
New Revision: 152064

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=152064
Log:
        PR c/39779
        * c-typeck.c (build_binary_op) <short_shift>: Check that integer
        constant is more than zero.

testsuite/ChangeLog:

        PR c/39779
        * gcc.c-torture/compile/pr39779.c: New test.


Added:
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr39779.c
Modified:
    branches/gcc-4_4-branch/gcc/ChangeLog
    branches/gcc-4_4-branch/gcc/c-typeck.c
    branches/gcc-4_4-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug rtl-optimization/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[uros at gcc dot gnu dot org]

------- Comment #14 from uros at gcc dot gnu dot org  2009-09-23 10:19 -------
Subject: Bug 39779

Author: uros
Date: Wed Sep 23 10:18:46 2009
New Revision: 152066

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=152066
Log:
        PR c/39779
        * c-typeck.c (build_binary_op) <short_shift>: Check that integer
        constant is more than zero.

testsuite/ChangeLog:

        PR c/39779
        * gcc.c-torture/compile/pr39779.c: New test.


Added:
    branches/gcc-4_3-branch/gcc/testsuite/gcc.c-torture/compile/pr39779.c
Modified:
    branches/gcc-4_3-branch/gcc/ChangeLog
    branches/gcc-4_3-branch/gcc/c-typeck.c
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779

[Bug c/39779] ICE shifting byte to the right with constant > 7FFFFFFF

[ubizjak at gmail dot com]

------- Comment #15 from ubizjak at gmail dot com  2009-09-23 10:24 -------
Fixed.


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
          Component|rtl-optimization            |c
         Resolution|                            |FIXED
   Target Milestone|---                         |4.3.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39779