Backport rev 185083 from google/main

Backport rev 185083 from google/main

Patch to add builtins to detect CPU type:
========================================

I have ported the patch from google/gcc-4_6 to google/main.  I also want this
patch to be considered for trunk.  Please see this discussion:
http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01355.html
when this patch for reviewed the last time.

One of the main concerns was about making CPU detection initialization a
constructor. The main point raised was about constructor ordering. I have now
added a priority value to the CPU detection constructor to make it very high
priority so that it is guaranteed to fire before every constructor without
an explicitly marked priority value of 101.  However, IFUNC initializers
will still fire before this constructor, so the cpu initialization routine
has to be explicitly called in such initializers for which I have added a
builtin: __builtin_cpu_init ().

I would like to reopen discussions on this to make it suitable for trunk
this time around.

This patch adds the following new builtins:

__builtin_cpu_init
__builtin_cpu_supports_cmov
__builtin_cpu_supports_mmx
__builtin_cpu_supports_popcount
__builtin_cpu_supports_sse
__builtin_cpu_supports_sse2
__builtin_cpu_supports_sse3
__builtin_cpu_supports_ssse3
__builtin_cpu_supports_sse4_1
__builtin_cpu_supports_sse4_2
__builtin_cpu_is_amd
__builtin_cpu_is_intel_atom
__builtin_cpu_is_intel_core2
__builtin_cpu_is_intel
__builtin_cpu_is_intel_corei7
__builtin_cpu_is_intel_corei7_nehalem
__builtin_cpu_is_intel_corei7_westmere
__builtin_cpu_is_intel_corei7_sandybridge
__builtin_cpu_is_amdfam10
__builtin_cpu_is_amdfam10_barcelona
__builtin_cpu_is_amdfam10_shanghai
__builtin_cpu_is_amdfam10_istanbul
__builtin_cpu_is_amdfam15_bdver1
__builtin_cpu_is_amdfam15_bdver2

        * config/i386/i386.c (build_struct_with_one_bit_fields): New function.
        (make_var_decl): New function.
        (get_field_from_struct): New function.
        (fold_builtin_target): New function.
        (ix86_fold_builtin): New function.
        (ix86_expand_builtin): Expand new builtins by folding them.
        (make_platform_builtin): New functions.
        (ix86_init_platform_type_builtins): Make the new builtins.
        (ix86_init_builtins): Make new builtins to detect CPU type.
        (TARGET_FOLD_BUILTIN): New macro.
        (IX86_BUILTIN_CPU_SUPPORTS_CMOV): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS_MMX): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS_SSE): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS_SSE2): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS_SSE3): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS_SSSE3): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_1): New enum value.
        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_2): New enum value.
        (IX86_BUILTIN_CPU_INIT): New enum value.
        (IX86_BUILTIN_CPU_IS_AMD): New enum value.
        (IX86_BUILTIN_CPU_IS_INTEL): New enum value.
        (IX86_BUILTIN_CPU_IS_INTEL_ATOM): New enum value.
        (IX86_BUILTIN_CPU_IS_INTEL_CORE2): New enum value.
        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM): New enum value.
        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE): New enum value.
        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE): New enum value.
        (IX86_BUILTIN_CPU_IS_AMDFAM10_BARCELONA): New enum value.
        (IX86_BUILTIN_CPU_IS_AMDFAM10_SHANGHAI): New enum value.
        (IX86_BUILTIN_CPU_IS_AMDFAM10_ISTANBUL): New enum value.
        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1): New enum value.
        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2): New enum value.
        * config/i386/i386-builtin-types.def: New function type.
        * testsuite/gcc.target/builtin_target.c: New testcase.

        * 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 symbols __cpu_model
        and __cpu_features.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/google@185093 138bc75d-0d04-0410-961f-82ee72b054a4