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From: "daniel at eyoman dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/108715] New: Infinite loop in the generated assembly with -Os
 when strlen is defined in the code
Date: Wed, 08 Feb 2023 10:29:33 +0000
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X-Bugzilla-Version: 12.2.1
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108715

            Bug ID: 108715
           Summary: Infinite loop in the generated assembly with -Os when
                    strlen is defined in the code
           Product: gcc
           Version: 12.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: daniel at eyoman dot com
  Target Milestone: ---

Created attachment 54426
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D54426&action=3Dedit
C file

Hi,

The attached source file is compiled on GCC 12.2.1 with the following comma=
nd:
gcc -save-temps -Wall -Wextra -Os strlen_bug.c -o strlen_bug

The assembly file, obtained with objdump -d strlen_bug, shows that:
- the for loop dealing with the length calculation has been removed by strl=
en
- the strlen label jumps to itself
- the program never ends

If the strlen function is removed from the code, the problem doesn't occur.

I wanted to attach the assembly and preprocessed files but I could attach o=
nly
one.=