[Bug tree-optimization/49018] New: Inline assembly block executed outside conditional check with "-O1 -ftree-vrp"

[Bug tree-optimization/49018] New: Inline assembly block executed outside conditional check with "-O1 -ftree-vrp"

[ted at thereisnospork dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49018

           Summary: Inline assembly block executed outside conditional
                    check with "-O1 -ftree-vrp"
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: ted@thereisnospork.com


In the following test case, the int3 instruction inserted by the assertion
macro is executed before any conditional check is performed when compiled with
"-O1 -ftree-vrp".  Without -ftree-vrp (as well as "-O2 -fno-tree-vrp"), the
instructions are ordered as expected.

$ cat asmvolatiletest.c 
#include <stdio.h>

#define CUSTOM_ASSERT( X ) if( !( X ) ) { __asm__ __volatile__ ( "int3" ); }

void testFunction( unsigned int a, unsigned int b )
{
    CUSTOM_ASSERT( a >= b );
    if( a < b )
    {
        printf( "Error: %u < %u\n", a, b );
    }
}

$ gcc -v
Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-mandriva-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-mandriva-linux-gnu
Configured with: ./configure --build=x86_64-mandriva-linux-gnu --prefix=/usr
--exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc
--datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64
--libexecdir=/usr/lib64 --localstatedir=/var --sharedstatedir=/usr/com
--mandir=/usr/share/man --infodir=/usr/share/info --x-includes=/usr/include
--x-libraries=/usr/lib64 --disable-libgcj --with-cloog --with-ppl
--enable-cloog-backend=ppl --disable-libssp --disable-libunwind-exceptions
--disable-werror --enable-__cxa_atexit --enable-bootstrap
--enable-checking=release --enable-gnu-unique-object
--enable-languages=c,ada,c++,fortran,go,lto,objc,obj-c++
--enable-linker-build-id --enable-plugin --enable-shared --enable-threads=posix
--with-system-zlib --with-bugurl=https://qa.mandriva.com/ --with-tune=generic
--with-arch_32=i686 --host=x86_64-mandriva-linux-gnu
--target=x86_64-mandriva-linux-gnu
Thread model: posix
gcc version 4.6.0 20110513 (prerelease) (GCC)

[Bug tree-optimization/49018] Inline assembly block executed outside conditional check with "-O1 -ftree-vrp"

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49018

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.05.17 10:50:48
         AssignedTo|unassigned at gcc dot       |rguenth at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-17 10:50:48 UTC ---
if-combine is doing this.  bb_no_side_effects_p returns true for the
basic-block with the asm.

Mine.

[Bug tree-optimization/49018] Inline assembly block executed outside conditional check with "-O1 -ftree-vrp"

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49018

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to work|                            |4.6.1, 4.7.0
         Resolution|                            |FIXED
   Target Milestone|---                         |4.6.1
      Known to fail|                            |4.6.0

--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-18 13:34:25 UTC ---
Fixed.

[Bug tree-optimization/49018] Inline assembly block executed outside conditional check with "-O1 -ftree-vrp"

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49018

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-18 13:33:24 UTC ---
Author: rguenth
Date: Wed May 18 13:33:21 2011
New Revision: 173861

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173861
Log:
2011-05-18  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/49018
    * gimple.c (gimple_has_side_effects): Volatile asms have side-effects.
    * tree-ssa-ifcombine.c (bb_no_side_effects_p): Use
    gimple_has_side_effects.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimple.c
    trunk/gcc/tree-ssa-ifcombine.c

[Bug tree-optimization/49018] Inline assembly block executed outside conditional check with "-O1 -ftree-vrp"

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49018

--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-18 13:33:56 UTC ---
Author: rguenth
Date: Wed May 18 13:33:53 2011
New Revision: 173862

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173862
Log:
2011-05-18  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/49018
    * gimple.c (gimple_has_side_effects): Volatile asms have side-effects.
    * tree-ssa-ifcombine.c (bb_no_side_effects_p): Use
    gimple_has_side_effects.

Modified:
    branches/gcc-4_6-branch/gcc/ChangeLog
    branches/gcc-4_6-branch/gcc/gimple.c
    branches/gcc-4_6-branch/gcc/tree-ssa-ifcombine.c