I get this with the gcc 4.3 snapshot from 20071130 when compiling thunderbird:

leto:/home/chtephan > LANG=C g++ -o breaks.o -c breaks.i -O2 -march=pentium-m
-fPIC
nsUnicodeToJamoTTF.cpp: In function ‘const JamoNormMap*
JamoClusterSearch(JamoNormMap, const JamoNormMap*, PRInt16)’:
nsUnicodeToJamoTTF.cpp:811: error: unable to find a register to spill in class
‘Q_REGS’
nsUnicodeToJamoTTF.cpp:811: error: this is the insn:
(insn:HI 209 207 211 2 nsUnicodeToJamoTTF.cpp:783 (parallel [
            (set (subreg:SI (reg:QI 134) 0)
                (lshiftrt:SI (reg:SI 4 si [136])
                    (const_int 8 [0x8])))
            (clobber (reg:CC 17 flags))
        ]) 358 {*lshrsi3_1} (expr_list:REG_DEAD (reg:SI 4 si [136])
        (expr_list:REG_UNUSED (reg:CC 17 flags)
            (nil))))


-- 
           Summary: spill failure with -O2 -fPIC -march=pentium-m on i386
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: christophe at saout dot de
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34312