[Bug debug/112703] New: [13/14 Regression] -fcompare-debug failure at -O1 and above

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112703

            Bug ID: 112703
           Summary: [13/14 Regression] -fcompare-debug failure at -O1 and
                    above
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: compare-debug-failure
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
                CC: aoliva at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 56681
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56681&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O -fcompare-debug testcase.C -save-temps
x86_64-pc-linux-gnu-gcc: error: testcase.C: '-fcompare-debug' failure

$ diff -u *gkd
--- a-testcase.C.gkd    2023-11-24 18:57:06.420042167 +0100
+++ a-testcase.gk.C.gkd 2023-11-24 18:57:06.450042167 +0100
@@ -67,7 +67,7 @@
         (nil))
     (nil))
 (insn # 0 0 4 (set (reg:SI 0 ax [orig:98 <retval> ] [98])
-        (const_int 1 [0x1])) "testcase.C":7:32 discrim 3# {*movsi_internal}
+        (const_int 1 [0x1])) "testcase.C":7:32 discrim 4# {*movsi_internal}
      (nil))
 (jump_insn # 0 0 4 (set (pc)
         (label_ref #)) "testcase.C":7:32# {jump}

$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r14-5822-20231124121307-g3eb9cae6d37-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --with-cloog --with-ppl --with-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r14-5822-20231124121307-g3eb9cae6d37-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.0 20231124 (experimental) (GCC)