[Bug middle-end/81443] gcc-7.1.0/MIPS N32: build/genrecog.o: virtual memory exhausted: Cannot allocate memory

[kumba at gentoo dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81443

--- Comment #7 from Joshua Kinard <kumba at gentoo dot org> ---
(In reply to Eric Botcazou from comment #6)
> Please retry with the current 7 branch, it contains additional fixes.

I did about a week ago.  Tried building gcc-7-branch HEAD with both gcc-6.4.0
and gcc-5.3.0, and both failed in the same spot.  If something was added in the
last week, I can re-test.  I also tried gcc-HEAD with gcc-6.4.0 and that also
failed.

FWIW, reversing PR59461 (some manual edits required) on gcc-7_1_0-release
compiles cleanly, which is the first time that's happened on this machine under
N32.  Successful builds on this machine take about 8 hours.  Fail
builds....~3-4 hours.  It's during stage2-bubble when compiling genrecog.c will
bail out, claiming no more virtual memory (2GB RAM + 3GB of swap).  So PR59461
clearly has some kind of issue on N32, with -march=mips3 or -march=r12000
(build machine is an SGI Octane w/ an R14000 CPU, so fairly old school).

The only other working MIPS machine I have is an SGI O2 with a rare RM7000 CPU.
 But gcc on that thing takes about 2-3 days for a successful build.  However,
it is running O32 ABI under uclibc-ng, so odds are likely gcc-7.x would compile
successfully.