how to find an unrecognizable insn

[Shinpei Kato <shinny at j02 dot itscom dot net>]

Hi,

I faced a following error during compiling _erand48_r in newlib.
Actually I'm converting mips gcc to our arch (porting gcc).

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/home/shinpei/research/compiler/mips-rmt/build-gcc-3.4.0/gcc/xgcc -B/home/shinpei/research/compiler/mips-rmt/build-gcc-3.4.0/gcc/ -nostdinc -B/home/shinpei/research/compiler/mips-rmt/build-gcc-3.4.0/mips-elf/newlib/ -isystem /home/shinpei/research/compiler/mips-rmt/build-gcc-3.4.0/mips-elf/newlib/targ-include -isystem /home/shinpei/research/compiler/mips-rmt/gcc-3.4.0/newlib/libc/include -B/usr/local/mips/mips-elf/bin/ -B/usr/local/mips/mips-elf/lib/ -isystem /usr/local/mips/mips-elf/include -isystem /usr/local/mips/mips-elf/sys-include -DPACKAGE=\"newlib\" -DVERSION=\"1.12.0\"  -I. -I../../../../../gcc-3.4.0/newlib/libc/stdlib  -O2 -DMISSING_SYSCALL_NAMES -fno-builtin    -O2 -g -O2  -O2 -g -O2 -c ../../../../../gcc-3.4.0/newlib/libc/stdlib/erand48.c
../../../../../gcc-3.4.0/newlib/libc/stdlib/erand48.c: In function `_erand48_r':../../../../../gcc-3.4.0/newlib/libc/stdlib/erand48.c:25: error: unrecognizable insn:
(insn 71 25 26 0 ../../../../../gcc-3.4.0/newlib/libc/stdlib/erand48.c:22 (set (subreg:HI (reg:SI 34 $f2) 2)
        (mem:HI (reg/v/f:SI 16 $16 [orig:175 xseed ] [175]) [8 S2 A16])) -1 (nil)
    (nil))
../../../../../gcc-3.4.0/newlib/libc/stdlib/erand48.c:25: internal compiler error: in extract_insn, at recog.c:2083
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
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It seems the cause is failing compiling ldexp() function in _erand48_r() and gcc couldn't find a proper insn.
I can't see what kind of insn my machine description is lacking.
Since I'm still newbie for porting gcc, could you please help me to get it?


Thanks,
Shinpei Kato