[Bug rtl-optimization/51469] New: attr-ifunc-* tests fail on PowerPC if --enable-gnu-indirect-function is used

[meissner at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51469

             Bug #: 51469
           Summary: attr-ifunc-* tests fail on PowerPC if
                    --enable-gnu-indirect-function is used
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: meiss...@gcc.gnu.org
        ReportedBy: meiss...@gcc.gnu.org
              Host: powerpc64-linux power-linux
            Target: powerpc64-linux
             Build: powerpc64-linux


The tests:
gcc.dg/attr-ifunc-1.c
gcc.dg/attr-ifunc-3.c
gcc.dg/attr-ifunc-4.c
gcc.dg/attr-ifunc-5.c
g++.dg/ext/attr-ifunc-1.C
g++.dg/ext/attr-ifunc-2.C
g++.dg/ext/attr-ifunc-3.C

all fail on PowerPC linux when the compiler is configured with
--enable-gnu-indirect-function

I traced this down, and the problem with the tests is that the gnu indirect
function (with the ifunc attribute) is in the same module as the call.  The
SYMBOL_REF_LOCAL bit is set for these functions.  Because SYMBOL_REF_LOCAL is
set, the PPC compiler assumes the call is in the same module and bypasses
putting a NOP after the BL instruction, which is used to restore the TOC. 
Because the BL is not followed by a NOP, the assembler and linker will not
create a PLT for the function and use the indirect function to return the
address of the function to use for the call.