+2017-06-05 Adhemerval Zanella <adhemerval.zanella@linaro.org>
+ H.J. Lu <hongjiu.lu@intel.com>
+
+ * sysdeps/x86/init-arch.h (PASTER1): New.
+ (EVALUATOR1): Likewise.
+ (PASTER2): Likewise.
+ (EVALUATOR2): Likewise.
+ (REDIRECT_NAME): Likewise.
+ (OPTIMIZE): Likewise.
+ (IFUNC_SELECTOR): Likewise.
+
2017-06-05 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/x86_64/strlen.S (PMINU): New.
# include <ldsodefs.h>
#endif
+/* These macros are used to implement ifunc selection in C. To implement
+ an ifunc function, foo, which returns the address of __foo_sse2 or
+ __foo_avx2:
+
+ #define foo __redirect_foo
+ #define __foo __redirect___foo
+ #include <foo.h>
+ #undef foo
+ #undef __foo
+ #define SYMBOL_NAME foo
+ #include <init-arch.h>
+
+ extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
+ extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
+
+ static inline void *
+ foo_selector (void)
+ {
+ if (use AVX2)
+ return OPTIMIZE (avx2);
+
+ return OPTIMIZE (sse2);
+ }
+
+ libc_ifunc_redirected (__redirect_foo, foo, foo_selector ());
+
+*/
+
+#define PASTER1(x,y) x##_##y
+#define EVALUATOR1(x,y) PASTER1 (x,y)
+#define PASTER2(x,y) __##x##_##y
+#define EVALUATOR2(x,y) PASTER2 (x,y)
+
+/* Basically set '__redirect_<symbol>' to use as type definition,
+ '__<symbol>_<variant>' as the optimized implementation and
+ '<symbol>_ifunc_selector' as the IFUNC selector. */
+#define REDIRECT_NAME EVALUATOR1 (__redirect, SYMBOL_NAME)
+#define OPTIMIZE(name) EVALUATOR2 (SYMBOL_NAME, name)
+#define IFUNC_SELECTOR EVALUATOR1 (SYMBOL_NAME, ifunc_selector)
+
#ifndef __x86_64__
/* Due to the reordering and the other nifty extensions in i686, it is
not really good to use heavily i586 optimized code on an i686. It's