x86: Install <bits/platform/x86.h> [BZ #27958]

1. Install <bits/platform/x86.h> for <sys/platform/x86.h> which includes
<bits/platform/x86.h>.
2. Rename HAS_CPU_FEATURE to CPU_FEATURE_PRESENT which checks if the
processor has the feature.
3. Rename CPU_FEATURE_USABLE to CPU_FEATURE_ACTIVE which checks if the
feature is active.  There may be other preconditions, like sufficient
stack space or further setup for AMX, which must be satisfied before the
feature can be used.

This fixes BZ #27958.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 10 insertions, 8 deletions

diff --git a/manual/platform.texi b/manual/platform.texi
index c56ba7d413..d5fdc5bd05 100644
--- a/manual/platform.texi
+++ b/manual/platform.texi
@@ -148,14 +148,16 @@ Return a pointer to x86 CPU feature structure used by query macros for x86
 CPU feature @var{leaf}.
 @end deftypefun
 
-@deftypefn Macro int HAS_CPU_FEATURE (@var{name})
+@deftypefn Macro int CPU_FEATURE_PRESENT (@var{name})
 This macro returns a nonzero value (true) if the processor has the feature
 @var{name}.
 @end deftypefn
 
-@deftypefn Macro int CPU_FEATURE_USABLE (@var{name})
+@deftypefn Macro int CPU_FEATURE_ACTIVE (@var{name})
 This macro returns a nonzero value (true) if the processor has the feature
-@var{name} and the feature is supported by the operating system.
+@var{name} and the feature is active.  There may be other preconditions,
+like sufficient stack space or further setup for AMX, which must be
+satisfied before the feature can be used.
 @end deftypefn
 
 The supported processor features are:
@@ -685,20 +687,20 @@ You could query if a processor supports @code{AVX} with:
 #include <sys/platform/x86.h>
 
 int
-support_avx (void)
+avx_present (void)
 @{
-  return HAS_CPU_FEATURE (AVX);
+  return CPU_FEATURE_PRESENT (AVX);
 @}
 @end smallexample
 
-and if @code{AVX} is usable with:
+and if @code{AVX} is active and may be used with:
 
 @smallexample
 #include <sys/platform/x86.h>
 
 int
-usable_avx (void)
+avx_active (void)
 @{
-  return CPU_FEATURE_USABLE (AVX);
+  return CPU_FEATURE_ACTIVE (AVX);
 @}
 @end smallexample