[Bug rtl-optimization/37659] New: unable to find a register to spill in class ‘AREG’

[Bug rtl-optimization/37659] New: unable to find a register to spill in class ‘AREG’

[edwintorok at gmail dot com]

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While reducing the testcase for PR37658 I found another bug:

$ gcc-4.3 -fschedule-insns testcase.i
...
testcase.i:193: error: unable to find a register to spill in class ‘AREG’
testcase.i:193: error: this is the insn:
(insn 17782 17785 17783 1528 testcase.i:189 (parallel [
            (set (reg:SI 1 dx [9986])
                (div:SI (reg:SI 3 bx [orig:524 D.8216 ] [524])
                    (reg:SI 1 dx [orig:522 D.8218 ] [522])))
            (set (reg:SI 9987)
                (mod:SI (reg:SI 3 bx [orig:524 D.8216 ] [524])
                    (reg:SI 1 dx [orig:522 D.8218 ] [522])))
            (clobber (reg:CC 17 flags))
        ]) 318 {*divmodsi4_nocltd} (expr_list:REG_DEAD (reg:SI 3 bx [orig:524
D.8216 ] [524])
        (expr_list:REG_DEAD (reg:SI 1 dx [orig:522 D.8218 ] [522])
            (expr_list:REG_UNUSED (reg:SI 9987)
                (expr_list:REG_UNUSED (reg:CC 17 flags)
                    (nil))))))
testcase.i:193: confused by earlier errors, bailing out
Preprocessed source stored into /tmp/ccA3kPTQ.out file, please attach this to
your bugreport.

This happens with all gcc versions I have here (with slightly different error
message):
$ gcc-4.3 -v
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.3.2-1'
--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3
--program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug
--enable-objc-gc --enable-mpfr --enable-cld --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.3.2 (Debian 4.3.2-1)

$ gcc-4.2 -v
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.2
--program-suffix=-4.2 --enable-clocale=gnu --enable-libstdcxx-debug
--enable-objc-gc --enable-mpfr --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.2.4 (Debian 4.2.4-3)

$ gcc-4.1 -v
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --enable-languages=c,c++ --prefix=/usr
--enable-shared --with-system-zlib --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --enable-nls
--with-gxx-include-dir=/usr/include/c++/4.1.3 --program-suffix=-4.1
--enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug
--enable-checking=release x86_64-linux-gnu
Thread model: posix
gcc version 4.1.3 20080623 (prerelease) (Debian 4.1.2-23)


-- 
           Summary: unable to find a register to spill in class ‘AREG’
           Product: gcc
           Version: 4.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: edwintorok at gmail dot com
 GCC build triplet: x86_64-linux-gnu
  GCC host triplet: x86_64-linux-gnu
GCC target triplet: x86_64-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37659

[Bug rtl-optimization/37659] unable to find a register to spill in class ‘AREG’

[edwintorok at gmail dot com]

------- Comment #1 from edwintorok at gmail dot com  2008-09-27 16:28 -------
Created an attachment (id=16416)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16416&action=view)
file dumped by gcc 

This is the file dumped by gcc, I am trying to get a reduced testcase using
delta, will attach here when I have it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37659

[Bug rtl-optimization/37659] unable to find a register to spill in class ‘AREG’

[edwintorok at gmail dot com]

------- Comment #2 from edwintorok at gmail dot com  2008-09-27 16:40 -------
Reduced testcase:

/* gcc -fschedule-insns */
int foo(int a, int b) {
        return bar(foobar(b) / foobar(a));
}


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37659

[Bug rtl-optimization/37659] unable to find a register to spill in class ‘AREG’

[edwintorok at gmail dot com]

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------- Comment #3 from edwintorok at gmail dot com  2008-09-27 16:43 -------
the error message for the above testcase:
$ gcc-4.3 -fschedule-insns v.i
v.i: In function ‘foo’:
v.i:3: error: unable to find a register to spill in class ‘AREG’
v.i:3: error: this is the insn:
(insn 17 20 18 2 v.i:2 (parallel [
            (set (reg:SI 1 dx [66])
                (div:SI (reg:SI 3 bx [orig:61 D.1552 ] [61])
                    (reg:SI 1 dx [orig:60 D.1553 ] [60])))
            (set (reg:SI 67)
                (mod:SI (reg:SI 3 bx [orig:61 D.1552 ] [61])
                    (reg:SI 1 dx [orig:60 D.1553 ] [60])))
            (clobber (reg:CC 17 flags))
        ]) 318 {*divmodsi4_nocltd} (expr_list:REG_DEAD (reg:SI 3 bx [orig:61
D.1552 ] [61])
        (expr_list:REG_DEAD (reg:SI 1 dx [orig:60 D.1553 ] [60])
            (expr_list:REG_UNUSED (reg:SI 67)
                (expr_list:REG_UNUSED (reg:CC 17 flags)
                    (nil))))))
v.i:3: confused by earlier errors, bailing out
Preprocessed source stored into /tmp/ccYIfwlr.out file, please attach this to
your bugreport.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37659

[Bug rtl-optimization/37659] unable to find a register to spill in class ‘AREG’

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2008-09-28 19:33 -------
This is a normal RA issue with targets like x86 where the RA does not
understand how to move instructions around to get back the register ...

*** This bug has been marked as a duplicate of 27001 ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37659