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From: "jay.foad at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/58152] New: ARM: unnecessary push before call to noreturn function
Date: Wed, 14 Aug 2013 09:46:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58152

            Bug ID: 58152
           Summary: ARM: unnecessary push before call to noreturn function
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jay.foad at gmail dot com

Created attachment 30652
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30652&action=edit
C source for testcase

On the attached test case I get:

$ gcc -marm -S -O2 ~/mul.c -o - -fomit-frame-pointer -march=armv6
...
mul:
    @ args = 0, pretend = 0, frame = 0
    @ frame_needed = 0, uses_anonymous_args = 0
    smull    r0, r1, r0, r1
    cmp    r1, r0, asr #31
    bxeq    lr
    stmfd    sp!, {r3, lr}
    bl    overflow

The stmfd instruction is completely unnecessary.

I'm using gcc built from svn r201719 configured with --target=arm-eabi.