Prepare use if IFUNC functions outside libc.so.

We use a callback function into libc.so to get access to the data
structure with the information and have special versions of the test
macros which automatically use this function.

2 files changed, 30 insertions, 2 deletions

diff --git a/sysdeps/x86_64/multiarch/init-arch.c b/sysdeps/x86_64/multiarch/init-arch.c
index 35fd19af0e..49b421eac8 100644
--- a/sysdeps/x86_64/multiarch/init-arch.c
+++ b/sysdeps/x86_64/multiarch/init-arch.c
@@ -86,3 +86,13 @@ __init_cpu_features (void)
   else
     __cpu_features.kind = arch_kind_other;
 }
+
+
+const struct cpu_features *
+__get_cpu_features (void)
+{
+  if (__cpu_features.kind == arch_kind_unknown)
+    __init_cpu_features ();
+
+  return &__cpu_features;
+}
diff --git a/sysdeps/x86_64/multiarch/init-arch.h b/sysdeps/x86_64/multiarch/init-arch.h
index 48a2127418..0151e8b95b 100644
--- a/sysdeps/x86_64/multiarch/init-arch.h
+++ b/sysdeps/x86_64/multiarch/init-arch.h
@@ -54,10 +54,28 @@ extern void __init_cpu_features (void) attribute_hidden;
       __init_cpu_features ();				\
   while (0)
 
+/* Used from outside libc.so to get access to the CPU features structure.  */
+extern const struct cpu_features *__get_cpu_features (void)
+     __attribute__ ((const));
+
 /* Following are the feature tests used throughout libc.  */
 
-#define HAS_POPCOUNT \
+#ifndef NOT_IN_libc
+# define HAS_POPCOUNT \
   ((__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx & (1 << 23)) != 0)
 
-#define HAS_SSE4_2 \
+# define HAS_SSE4_2 \
   ((__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx & (1 << 20)) != 0)
+
+# define HAS_FMA \
+  ((__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx & (1 << 12)) != 0)
+#else
+# define HAS_POPCOUNT \
+  ((__get_cpu_features ()->cpuid[COMMON_CPUID_INDEX_1].ecx & (1 << 23)) != 0)
+
+# define HAS_SSE4_2 \
+  ((__get_cpu_features ()->cpuid[COMMON_CPUID_INDEX_1].ecx & (1 << 20)) != 0)
+
+# define HAS_FMA \
+  ((__get_cpu_features ()->cpuid[COMMON_CPUID_INDEX_1].ecx & (1 << 12)) != 0)
+#endif