[Bug c/82364] New: [7 Regression] Enormous memory usage when building on 32bit i386 with >= -O1

["bunk at stusta dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82364

            Bug ID: 82364
           Summary: [7 Regression] Enormous memory usage when building on
                    32bit i386 with >= -O1
           Product: gcc
           Version: 7.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bunk at stusta dot de
  Target Milestone: ---

Created attachment 42263
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42263&action=edit
piglit-util-gl-enum-gen.i

piglit fails to build on 32bit i386 in Debian unstable, the problem is:

$ /usr/bin/time -f "%M" gcc-6 piglit-util-gl-enum-gen.i -c -O0
40364
$ /usr/bin/time -f "%M" gcc-6 piglit-util-gl-enum-gen.i -c -O1
54460
$ /usr/bin/time -f "%M" gcc-6 piglit-util-gl-enum-gen.i -c -O2
79688
$ /usr/bin/time -f "%M" gcc-6 piglit-util-gl-enum-gen.i -c -O3
79904
$ /usr/bin/time -f "%M" gcc-7 piglit-util-gl-enum-gen.i -c -O0
41732
$ /usr/bin/time -f "%M" gcc-7 piglit-util-gl-enum-gen.i -c -O1
679260
$ /usr/bin/time -f "%M" gcc-7 piglit-util-gl-enum-gen.i -c -O2

cc1: out of memory allocating 396567608 bytes after a total of 3083091968 bytes
Command exited with non-zero status 1
3476008
$ /usr/bin/time -f "%M" /usr/lib/gcc-snapshot/bin/gcc piglit-util-gl-enum-gen.i
-c -O0
42044
$ /usr/bin/time -f "%M" /usr/lib/gcc-snapshot/bin/gcc piglit-util-gl-enum-gen.i
-c -O1
51152
$ /usr/bin/time -f "%M" /usr/lib/gcc-snapshot/bin/gcc piglit-util-gl-enum-gen.i
-c -O2
83636
$ /usr/bin/time -f "%M" /usr/lib/gcc-snapshot/bin/gcc piglit-util-gl-enum-gen.i
-c -O3
83668
$ gcc-6 --version
gcc-6 (Debian 6.4.0-7) 6.4.0 20170920
...
$ gcc-7 --version
gcc-7 (Debian 7.2.0-7) 7.2.0
...
$ /usr/lib/gcc-snapshot/bin/gcc --version
gcc (Debian 20170923-1) 8.0.0 20170923 (experimental) [trunk revision 253114]
...
$ 

7.2.0-7 is based on SVN 20170923 (r253114) from the gcc-7-branch.

Building on 64bit amd64 with -m32 has a normal memory usage (98 MB).