[Bug target/92303] New: [10 regression] gcc.target/sparc/ultrasp12.c times out

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92303

            Bug ID: 92303
           Summary: [10 regression] gcc.target/sparc/ultrasp12.c times out
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: ebotcazou at gcc dot gnu.org
  Target Milestone: ---
            Target: sparc*-*-solaris2.11

Between 20190626 (r272695) and 20190627 (r272755), gcc.target/sparc/ultrasp12.c
compilation began to time out on Solaris/SPARC:

+WARNING: gcc.target/sparc/ultrasp12.c (test for excess errors) program timed
out.
+FAIL: gcc.target/sparc/ultrasp12.c (test for excess errors)

With the 7.1.0/8.1.0/9.1.0 release compilers, the testcase compiles in about
1 sec.  The timeout also happens on the gcc-8 and gcc-9 branches now.  Maybe
due to different checking options?

Checking the running cc1 with pstack shows it running somewhere in LRA:

 0093c0d4 update_lives(int, bool) (131, 0, 1717088, 1a08898, 607c, 4d3) + b4
(lra-assigns.c:393)
 00940b4c lra_assign(bool&) (17170a8, 1715800, 274b, 16f3414, 7260, 131) + 310c
(lra-assigns.c:1160)
 0093a9dc lra(__FILE*) (1715800, 16f0800, 1751cd0, 17170d4, 16e1e80, 17159f0) +
6d4 (lra.c:2482)
 008ec2f4 (anonymous namespace)::pass_reload::execute(function*) (178f820,
fa8b6000, 16dac00, 1747800, 16dac00, 16f0800) + e0 (ira.c:5511)

 00940b4c lra_assign(bool&) (17170a8, 1715800, 274b, 16f3414, 7260, 131) + 310c
(lra-assigns.c:1160)
 0093a9dc lra(__FILE*) (1715800, 16f0800, 1751cd0, 17170d4, 16e1e80, 17159f0) +
ro@colima 89 > pstack 28239|gc++filt
28239:  ./cc1 -fpreprocessed ultrasp12.i -mptr64 -mstack-bias -mno-v8plus -qui
 0095ad4c lra_create_live_ranges_1(bool, bool) (fa2ac8e8, 0, 2cdee14, 2d1e62,
fa8c09c0, 1) + 678 (lra-int.h:483)
 0095d738 lra_create_live_ranges(bool, bool) (1, 0, 2d3ba0, 789f, 0, 1718000) +
8 (lra-lives.c:1446)
 0093a964 lra(__FILE*) (1715800, 16f0800, 1751cd0, 17170d4, 16e1e80, 17159f0) +
65c (lra.c:2471)

 00956608 update_reg_eliminate(bitmap_head*) [clone .constprop.0] (0, 1, 0,
16e1e80, 1715800, fa1d8528) + 75c (rtl.h:882)
 009587c8 lra_eliminate(bool, bool) (0, 0, fa8c09c0, 1747800, fa8c09c0,
1717400) + 38c (lra-eliminations.c:1357)
 0093a930 lra(__FILE*) (1715800, 16f0800, 1751cd0, 17170d4, 16e1e80, 1) + 628
(lra.c:2441)