2012-04-24  Sriraman Tallam  <tmsriram@google.com>

This patch adds new builtins to check for cpu type and features. 

* __builtin_cpu_is ("<CPUNAME>")
* __builtin_cpu_supports ("<FEATURE>")

apart from the cpu init builtin, __builtin_cpu_init.

List of CPU names :

* "amd"
* "intel"
* "atom"
* "core2"
* "corei7"
* "nehalem"
* "westmere"
* "sandybridge"
* "amdfam10h"
* "barcelona"
* "shanghai"
* "istanbul"
* "bdver1"
* "bdver2"

List of CPU features :

* "cmov"
* "mmx"
* "popcnt"
* "sse"
* "sse2"
* "sse3"
* "ssse3"
* "sse4.1"
* "sse4.2"
* "avx"

        * config/i386/i386.c (build_processor_model_struct): New function.
        (make_var_decl): New function.
        (fold_builtin_cpu): New function.
        (ix86_fold_builtin): New function.
        (make_cpu_type_builtin): New function.
        (ix86_init_platform_type_builtins): New function.
        (ix86_expand_builtin): Expand new builtins by folding them.
        (ix86_init_builtins): Make new builtins to detect CPU type.
        (TARGET_FOLD_BUILTIN): New macro.
        (IX86_BUILTIN_CPU_INIT): New enum value.
        (IX86_BUILTIN_CPU_IS): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS): New enum value.
        * config/i386/i386-builtin-types.def: New function type.
        * testsuite/gcc.target/builtin_target.c: New testcase.
        * doc/extend.texi: Document builtins.

        * libgcc/config/i386/i386-cpuinfo.c: New file.
        * libgcc/config/i386/t-cpuinfo: New file.
        * libgcc/config.host: Include t-cpuinfo.
        * libgcc/config/i386/libgcc-glibc.ver: Version symbol __cpu_model.

From-SVN: r186789