[Bug target/96493] powerpc local call linkage failure

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96493

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Alan Modra <amodra@gcc.gnu.org>:

https://gcc.gnu.org/g:61e46440e8124ba605f7ff81aaf1a19176d0c14b

commit r10-8615-g61e46440e8124ba605f7ff81aaf1a19176d0c14b
Author: Alan Modra <amodra@gmail.com>
Date:   Thu Aug 6 14:12:21 2020 +0930

    PR96493, powerpc local call linkage failure

    This corrects current_file_function_operand, an operand predicate used
    to determine whether a symbol_ref is safe to use with the local_call
    patterns.  Calls between pcrel and non-pcrel code need to go via
    linker stubs.  In the case of non-pcrel code to pcrel the stub saves
    r2 but there needs to be a nop after the branch for the r2 restore.
    So the local_call patterns can't be used there.  For pcrel code to
    non-pcrel the local_call patterns could still be used, but I thought
    it better to not use them since the call isn't direct.  Code generated
    by the corresponding call_nonlocal_aix for pcrel is identical anyway.

    Incidentally, without the TREE_CODE () == FUNCTION_DECL test,
    gcc.c-torture/compile/pr37433.c and pr37433-1.c ICE.  Also, if you
    make the test more strict by disallowing an op without a
    SYMBOL_REF_DECL then a bunch of go and split-stack tests fail.  That's
    because a prologue call to __morestack can't have a following nop.
    (__morestack calls its caller at a fixed offset from the __morestack
    call!)

    gcc/
            PR target/96493
            * config/rs6000/predicates.md (current_file_function_operand):
Don't
            accept functions that differ in r2 usage.

    gcc/testsuite/
            * gcc.target/powerpc/pr96493.c: New file.

    (cherry picked from commit f8ac30f1653ff69706c35af6d725f1d330600f11)