[Bug target/81193] PowerPC GCC __builtin_cpu_is and __builtin_cpu_supports should warn about old libraries

["meissner at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81193

--- Comment #14 from Michael Meissner <meissner at gcc dot gnu.org> ---
Author: meissner
Date: Wed Jul 19 20:31:53 2017
New Revision: 250368

URL: https://gcc.gnu.org/viewcvs?rev=250368&root=gcc&view=rev
Log:
[gcc]
2017-07-19  Michael Meissner  <meissner@linux.vnet.ibm.com>

        Back port from trunk
        2017-07-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

        PR target/81193
        * config/rs6000/rs6000-c.c (rs6000_cpu_cpp_builtins): If GLIBC
        provides the hardware capability bits, define the macro
        __BUILTIN_CPU_SUPPORTS__.
        * config/rs6000/rs6000.c (cpu_expand_builtin): Generate a warning
        if GLIBC does not provide the hardware capability bits.  Add a
        gcc_unreachable call if the built-in cpu function is neither
        __builtin_cpu_is nor __builtin_cpu_supports.
        * doc/extend.texi (PowerPC built-in functions): Document that
        GLIBC 2.23 or newer is needed by __builtin_cpu_is and
        __builtin_cpu_supports.  Document the macros defined by GCC if the
        newer GLIBC is available.

[gcc/testsuite]
2017-07-19  Michael Meissner  <meissner@linux.vnet.ibm.com>

        Back port from trunk
        2017-07-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

        PR target/81193
        * gcc.target/powerpc/cpu-builtin-1.c: Change test to use #ifdef
        __BUILTIN_CPU_SUPPORTS to see if the GLIBC is new enough that
        __builtin_cpu_is and __builtin_cpu_supports are supported.


Modified:
    branches/gcc-7-branch/gcc/ChangeLog
    branches/gcc-7-branch/gcc/config/rs6000/rs6000-c.c
    branches/gcc-7-branch/gcc/config/rs6000/rs6000.c
    branches/gcc-7-branch/gcc/doc/extend.texi
    branches/gcc-7-branch/gcc/testsuite/ChangeLog
    branches/gcc-7-branch/gcc/testsuite/gcc.target/powerpc/cpu-builtin-1.c