[Bug target/112523] New: [14 regression] ICE in ipa_push_agg_values_from_jfunc, at ipa-cp.cc:2139

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112523

            Bug ID: 112523
           Summary: [14 regression] ICE in ipa_push_agg_values_from_jfunc,
                    at ipa-cp.cc:2139
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: build, ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: sayle at gcc dot gnu.org
  Target Milestone: ---
              Host: i386-pc-solaris2.11
            Target: i386-pc-solaris2.11
             Build: i386-pc-solaris2.11

Between 20231110 and 20231123, Solaris/x86 bootstrap got broken: both the 32
and 64-bit libgcc/unwind-dw2.c and unwind-dw2-fde-dip.c cause an ICE:

during IPA pass: inline
/vol/gcc/src/hg/master/local/libgcc/unwind-dw2.c:1472: internal compiler error:
in ipa_push_agg_values_from_jfunc, at ipa-cp.cc:2139
 1472 |
      |

A reghunt identified this patch

commit 0a140730c970870a5125beb1114f6c01679a040e
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Mon Nov 13 09:05:16 2023 +0000

    i386: Improve reg pressure of double word right shift then truncate.

as the culprit.  I've reduce unwind-dw2.c to the attached testcase.  The
failure can be seen with

cc1 -fpreprocessed unwind-dw2.i -quiet -mtune=generic -march=pentium4 -O2