[Bug target/115028] New: [15 regression] gcc.target/i386/pr101950-2.c FAILs

["ro at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115028

            Bug ID: 115028
           Summary: [15 regression] gcc.target/i386/pr101950-2.c FAILs
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
  Target Milestone: ---
            Target: i386-pc-solaris2.11

Between 20240506 (80c03ac8041340b29325f86ed58ea8bd40a55b99) and 20240507
(bf10f0db20db1598157505b373098bc93c66b915),
the 64-bit gcc.target/i386/pr101950-2.c test regressed on Solaris/x86:

FAIL: gcc.target/i386/pr101950-2.c scan-assembler-times \\txor[ql]\\t 2

There are 3 instances of xor[ql] now instead of the expected two:

        xorq    %rax, %rdi
        xorl    %eax, %edi
        xorl    %eax, %eax

where the gcc-14 branch has

        xorq    %rdi, %rax
        xorl    %edi, %eax

The additional one is from

@@ -20,8 +20,9 @@
 .LFB1:
        movl    %edi, %eax
        sarl    $31, %eax
-       xorl    %edi, %eax
-       lzcntl  %eax, %eax
+       xorl    %eax, %edi
+       xorl    %eax, %eax
+       lzcntl  %edi, %eax
        subl    $1, %eax
        ret
 .LFE1:

I'm attaching both gcc-14 and trunk assembler output.