<sys/platform/x86.h>: Add APX support

Add support for Intel Advanced Performance Extensions:

https://www.intel.com/content/www/us/en/developer/articles/technical/advanced-performance-extensions-apx.html

to <sys/platform/x86.h>.

manual/platform.texi

@@ -209,6 +209,9 @@ The supported processor features are:
 @item
 @code{AMX_TILE} -- Tile architecture.
 
+@item
+@code{APX_F} -- The APX instruction extensions.
+
 @item
 @code{ARCH_CAPABILITIES} -- IA32_ARCH_CAPABILITIES MSR.
 

sysdeps/x86/bits/platform/x86.h

@@ -312,6 +312,7 @@ enum
   x86_cpu_AVX_NE_CONVERT	= x86_cpu_index_7_ecx_1_edx + 5,
   x86_cpu_AMX_COMPLEX		= x86_cpu_index_7_ecx_1_edx + 8,
   x86_cpu_PREFETCHI		= x86_cpu_index_7_ecx_1_edx + 14,
+  x86_cpu_APX_F			= x86_cpu_index_7_ecx_1_edx + 21,
 
   x86_cpu_index_19_ebx
     = (CPUID_INDEX_19 * 8 * 4 * sizeof (unsigned int)

sysdeps/x86/cpu-features.c

@@ -226,6 +226,10 @@ update_active (struct cpu_features *cpu_features)
 	  CPU_FEATURE_SET_ACTIVE (cpu_features, AMX_COMPLEX);
 	}
 
+      /* APX is usable only if the APX state is supported by kernel.  */
+      if ((xcrlow & bit_APX_state) != 0)
+	CPU_FEATURE_SET_ACTIVE (cpu_features, APX_F);
+
       /* These features are usable only when OSXSAVE is enabled.  */
       CPU_FEATURE_SET (cpu_features, XSAVE);
       CPU_FEATURE_SET_ACTIVE (cpu_features, XSAVEOPT);

sysdeps/x86/include/cpu-features.h

@@ -319,6 +319,7 @@ enum
 #define bit_cpu_AVX_NE_CONVERT	(1u << 5)
 #define bit_cpu_AMX_COMPLEX	(1u << 8)
 #define bit_cpu_PREFETCHI	(1u << 14)
+#define bit_cpu_APX_F		(1u << 21)
 
 /* CPUID_INDEX_19.  */
 
@@ -562,6 +563,7 @@ enum
 #define index_cpu_AVX_NE_CONVERT CPUID_INDEX_7_ECX_1
 #define index_cpu_AMX_COMPLEX	CPUID_INDEX_7_ECX_1
 #define index_cpu_PREFETCHI	CPUID_INDEX_7_ECX_1
+#define index_cpu_APX_F		CPUID_INDEX_7_ECX_1
 
 /* CPUID_INDEX_19.  */
 
@@ -807,6 +809,7 @@ enum
 #define reg_AVX_NE_CONVERT	edx
 #define reg_AMX_COMPLEX		edx
 #define reg_PREFETCHI		edx
+#define reg_APX_F		edx
 
 /* CPUID_INDEX_19.  */
 
@@ -845,6 +848,7 @@ enum
 #define bit_ZMM16_31_state	(1u << 7)
 #define bit_XTILECFG_state	(1u << 17)
 #define bit_XTILEDATA_state	(1u << 18)
+#define bit_APX_state		(1u << 19)
 
 enum cpu_features_kind
 {

sysdeps/x86/tst-get-cpu-features.c

@@ -219,6 +219,7 @@ do_test (void)
   CHECK_CPU_FEATURE_PRESENT (AVX_NE_CONVERT);
   CHECK_CPU_FEATURE_PRESENT (AMX_COMPLEX);
   CHECK_CPU_FEATURE_PRESENT (PREFETCHI);
+  CHECK_CPU_FEATURE_PRESENT (APX_F);
   CHECK_CPU_FEATURE_PRESENT (AESKLE);
   CHECK_CPU_FEATURE_PRESENT (WIDE_KL);
   CHECK_CPU_FEATURE_PRESENT (PTWRITE);
@@ -390,6 +391,7 @@ do_test (void)
   CHECK_CPU_FEATURE_ACTIVE (AVX_NE_CONVERT);
   CHECK_CPU_FEATURE_ACTIVE (AMX_COMPLEX);
   CHECK_CPU_FEATURE_ACTIVE (PREFETCHI);
+  CHECK_CPU_FEATURE_ACTIVE (APX_F);
   CHECK_CPU_FEATURE_ACTIVE (AESKLE);
   CHECK_CPU_FEATURE_ACTIVE (WIDE_KL);
   CHECK_CPU_FEATURE_ACTIVE (PTWRITE);