[Bug rtl-optimization/114881] New: Very slow compilation on SPARC

[Bug rtl-optimization/114881] New: Very slow compilation on SPARC

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114881

            Bug ID: 114881
           Summary: Very slow compilation on SPARC
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ian at airs dot com
  Target Milestone: ---

Created attachment 58059
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58059&action=edit
Test case

This is repeat of PR 53125, which was closed in 2012.

The attached test case is a conversion to C of a machine generated test case in
Go (the machine generated Go source is in
gcc/testsuite/go.test/test/cmplxdivide1.go).

When I compile this test case without optimization on an x86_64 GNU/Linux
system, it takes 9.7 seconds.  With -O2 it takes 4.9 seconds.

When I compile this test case without optimization on a SPARC Solaris 2.11
system, it takes 3 minutes 30 seconds.  With -O2 it takes 2 minutes 30 seconds.

The SPARC machine is slower than the x86_64 machine.  But it's not that much
slower.  The time difference is extreme.

In -ftime-report on the SPARC system, most of the time is:

 integrated RA                      :  33.43 ( 16%)   0.05 (  4%)  33.56 ( 16%)
   12M ( 14%)
 LRA hard reg assignment            : 144.62 ( 70%)   0.35 ( 30%) 145.52 ( 70%)
    0  (  0%)