Bug#100166: gcc-3.0: internal compiler error: unrecognized insn

[greg@wooledge.org]

Package: gcc-3.0
Version: 1:3.0-0pre010526
Severity: normal

Building XFree86 4.1.0 from source, with gcc-3.0, using the options
"-O3 -funroll-loops -march=k6":

s3v_dac.c: In function `S3VCommonCalcClock':
s3v_dac.c:110: Unrecognizable insn:
(insn 585 583 587 (set (reg:SI 212)
        (zero_extend:SI (reg/v:QI 59))) -1 (nil)
    (nil))
s3v_dac.c:110: Internal compiler error in extract_insn, at recog.c:2210

s3v_dac.c is 109 lines long, so line 110 is after EOF.

If I enter this directory and issue the "make all CDEBUGFLAGS=-O2"
command, it compiles successfully.  In fact, it also builds with
'make all CDEBUGFLAGS="-O3 -funroll-loops"', and with "-g -march=k6",
and with "-O3 -march=k6", and with "-funroll-loops -march=k6", and with
"-O -funroll-loops -march=k6".

I can only get it to blow up if I combine "-march=k6" and "-funroll-loops"
and "-O2" or higher optimization.

I can send the 109-line s3v_dac.c file if you need it, but it won't
compile without a slew of XFree86 headers.

-- System Information
Debian Release: testing/unstable
Kernel Version: Linux jekyll 2.2.19 #4 Mon Mar 26 16:19:05 EST 2001 i586 unknown

Versions of the packages gcc-3.0 depends on:
ii  binutils       2.11.90.0.7-2  The GNU assembler, linker and binary utiliti
ii  cpp-3.0        3.0-0pre010526 The GNU C preprocessor.
ii  gcc-3.0-base   3.0-0pre010526 The GNU compiler collection (base package).
ii  libc6          2.2.3-5        GNU C Library: Shared libraries and Timezone
ii  libgcc0        3.0-0pre010526 GCC support library.