[Bug rtl-optimization/52148] New: [4.7 regression] ICE: in spill_failure, at reload1.c:2120

[mhlavink at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52148

             Bug #: 52148
           Summary: [4.7 regression] ICE: in spill_failure, at
                    reload1.c:2120
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mhlavink@redhat.com


Created attachment 26601
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26601
pre-processed reproducer

gcc 4.7 fails on code that was working in 4.6 without any problem

Version: 4.7.0-20120204
Target: avr

Problem happens only when optimization (O2 or O3) is used.

Pre-processed reproducer attached.

$ avr-gcc -mmcu=atmega64 -O2  allsrce.cpp -c -o allsrc.o

allsrce.cpp: In function 'void applyExpos(int16_t*, uint8_t)':
allsrce.cpp:68:1: error: unable to find a register to spill in class
'POINTER_REGS'
allsrce.cpp:68:1: error: this is the insn:
(insn 17 16 9 2 (parallel [
            (set (mem:BLK (reg:HI 26 r26) [0 A8])
                (mem:BLK (reg/v/f:HI 97 [ anas ]) [0 A8]))
            (unspec [
                    (const_int 0 [0])
                ] UNSPEC_MOVMEM)
            (use (reg:QI 24 r24 [99]))
            (clobber (reg:HI 26 r26))
            (clobber (reg:HI 30 r30))
            (clobber (reg:QI 0 r0))
            (clobber (reg:QI 24 r24 [99]))
        ]) allsrce.cpp:49 29 {movmem_qi}
     (expr_list:REG_DEAD (reg:QI 24 r24 [99])
        (expr_list:REG_DEAD (reg:QI 27 r27)
            (expr_list:REG_UNUSED (reg:QI 24 r24 [99])
                (expr_list:REG_UNUSED (reg:QI 0 r0)
                    (expr_list:REG_UNUSED (reg:HI 30 r30)
                        (expr_list:REG_UNUSED (reg:HI 26 r26)
                            (nil))))))))
allsrce.cpp:68:1: internal compiler error: in spill_failure, at reload1.c:2120
Please submit a full bug report,
with preprocessed source if appropriate.


Additional information:
$ avr-gcc -v
Using built-in specs.
COLLECT_GCC=avr-gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/avr/4.7.0/lto-wrapper
Target: avr
Configured with: ../gcc-4.7-20120204/configure --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info --target=avr
--enable-languages=c,c++ --disable-nls --disable-libssp --with-system-zlib
--enable-version-specific-runtime-libs --with-pkgversion='Fedora 4.7-0.fc16.1'
--with-bugurl=https://bugzilla.redhat.com/
Thread model: single
gcc version 4.7.0 20120204 (experimental) (Fedora 4.7-0.fc16.1)