[Bug other/52391] New: [4.7 regression] genattrtab almost 5X slower for m68k than in 4.6 and earlier releases

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52391

             Bug #: 52391
           Summary: [4.7 regression] genattrtab almost 5X slower for m68k
                    than in 4.6 and earlier releases
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: mi...@it.uu.se


Building a gcc-4.7 cross to m68k-linux takes almost twice as long as it takes
for earlier releases, and most of the slowdown comes from genattrtab taking
almost 5 times longer.

Here's some numbers for build times and genattrtab times for the 4 latest gcc
versions (--target=m68k-linux --enable-languages=c --enable-checking=release,
non-parallel "make", on a 2.4GHz C2Q6600):

gcc-4.4-20120221:
    genattrtab: 2:13.31
    total: 9m17s

gcc-4.5-20120223:
    genattrtab: 1:48.17
    total: 9m10s

gcc-4.6-20120224:
    genattrtab: 1.44.05
    total: 9m14s

gcc-4.7-20120225:
    genattrtab: 8:25.99
    total: 16m21s

The genattrtab times are as reported by /usr/bin/time on Fedora 14, i.e.
minutes:seconds.fraction.

I haven't measured other target build times in detail, but my gut feeling is
that they're not nearly as bad as these, so it might be an issue with the m68k
target specifically or perhaps cc0 targets in general.