[Bug middle-end/46674] New: Weak alias was mistakenly optimized away

[jiez at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46674

           Summary: Weak alias was mistakenly optimized away
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jiez@gcc.gnu.org


Created attachment 22537
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22537
The test case

This patch

http://gcc.gnu.org/ml/gcc-patches/2010-10/msg02275.html

causes a failure when building glibc for arm-none-linux-gnueabi target. The
reduced test case is attached.

Without this patch, memchr is defined in the assembly:

    .size    __memchr, .-__memchr
    .weak   __GI_memchr
    .hidden __GI_memchr
    .set    __GI_memchr,__memchr
    .global memchr
    .set    memchr,__GI_memchr
    .ident    "GCC: (GNU) 4.6.0 20101026 (experimental)"

but with this patch, memchr is not defined:

    .size    __memchr, .-__memchr
    .weak    __GI_memchr
    .hidden    __GI_memchr
    .set    __GI_memchr,__memchr
    .ident    "GCC: (GNU) 4.6.0 20101026 (experimental)"

When compiling the test case, -O is used on the command line.