Make dbl-64 atan and tan into weak aliases.

This patch converts the dbl-64 implementations of atan and tan into
weak aliases of __atan and __tan, in preparation for making them use
libm_alias_double.  Consequent changes are made to the x86_64
multiarch versions wrapping round them (with the dbl-64 functions,
like other such functions, being made not to define their aliases at
all if __atan or __tan are defined as macros by an including file).

Tested for x86_64, and with build-many-glibcs.py.

	* sysdeps/ieee754/dbl-64/s_atan.c (atan): Rename to __atan and
	define as weak alias of __atan.  Do not define any aliases if
	[__atan].
	[NO_LONG_DOUBLE] (__atanl): Define as strong alias of __atan.
	[NO_LONG_DOUBLE] (atanl): Define as weak alias of __atanl.
	* sysdeps/ieee754/dbl-64/s_tan.c (tan): Rename to __tan and define
	as weak alias of __tan.  Do not define any aliases if [__tan].
	[NO_LONG_DOUBLE] (__tanl): Define as strong alias of __tan.
	[NO_LONG_DOUBLE] (tanl): Define as weak alias of __tanl.
	* sysdeps/x86_64/fpu/multiarch/s_atan-avx.c (atan): Rename to
	__atan.
	* sysdeps/x86_64/fpu/multiarch/s_atan-fma.c (atan): Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_atan-fma4.c (atan): Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_atan.c (atan): Rename to __atan
	and define as weak alias of __atan.
	* sysdeps/x86_64/fpu/multiarch/s_tan-avx.c (tan): Rename to
	__atan.
	* sysdeps/x86_64/fpu/multiarch/s_tan-fma.c (tan): Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_tan-fma4.c (tan): Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_tan.c (tan): Rename to __tan and
	define as weak alias of __tan.

ChangeLog

@@ -1,3 +1,27 @@
+2017-10-02  Joseph Myers  <joseph@codesourcery.com>
+
+	* sysdeps/ieee754/dbl-64/s_atan.c (atan): Rename to __atan and
+	define as weak alias of __atan.  Do not define any aliases if
+	[__atan].
+	[NO_LONG_DOUBLE] (__atanl): Define as strong alias of __atan.
+	[NO_LONG_DOUBLE] (atanl): Define as weak alias of __atanl.
+	* sysdeps/ieee754/dbl-64/s_tan.c (tan): Rename to __tan and define
+	as weak alias of __tan.  Do not define any aliases if [__tan].
+	[NO_LONG_DOUBLE] (__tanl): Define as strong alias of __tan.
+	[NO_LONG_DOUBLE] (tanl): Define as weak alias of __tanl.
+	* sysdeps/x86_64/fpu/multiarch/s_atan-avx.c (atan): Rename to
+	__atan.
+	* sysdeps/x86_64/fpu/multiarch/s_atan-fma.c (atan): Likewise.
+	* sysdeps/x86_64/fpu/multiarch/s_atan-fma4.c (atan): Likewise.
+	* sysdeps/x86_64/fpu/multiarch/s_atan.c (atan): Rename to __atan
+	and define as weak alias of __atan.
+	* sysdeps/x86_64/fpu/multiarch/s_tan-avx.c (tan): Rename to
+	__atan.
+	* sysdeps/x86_64/fpu/multiarch/s_tan-fma.c (tan): Likewise.
+	* sysdeps/x86_64/fpu/multiarch/s_tan-fma4.c (tan): Likewise.
+	* sysdeps/x86_64/fpu/multiarch/s_tan.c (tan): Rename to __tan and
+	define as weak alias of __tan.
+
 2017-10-02  Szabolcs Nagy  <szabolcs.nagy@arm.com>
 
 	* math/w_lgamma.c: New file.

sysdeps/ieee754/dbl-64/s_atan.c

@@ -61,7 +61,7 @@ __signArctan (double x, double y)
 /* An ultimate atan() routine. Given an IEEE double machine number x,    */
 /* routine computes the correctly rounded (to nearest) value of atan(x). */
 double
-atan (double x)
+__atan (double x)
 {
   double cor, s1, ss1, s2, ss2, t1, t2, t3, t7, t8, t9, t10, u, u2, u3,
 	 v, vv, w, ww, y, yy, z, zz;
@@ -323,6 +323,10 @@ atanMp (double x, const int pr[])
   return y1;			/*if impossible to do exact computing */
 }
 
-#ifdef NO_LONG_DOUBLE
-weak_alias (atan, atanl)
+#ifndef __atan
+weak_alias (__atan, atan)
+# ifdef NO_LONG_DOUBLE
+strong_alias (__atan, __atanl)
+weak_alias (__atanl, atanl)
+# endif
 #endif

sysdeps/ieee754/dbl-64/s_tan.c

@@ -53,7 +53,7 @@ void __mptan (double, mp_no *, int);
 
 double
 SECTION
-tan (double x)
+__tan (double x)
 {
 #include "utan.h"
 #include "utan.tbl"
@@ -843,6 +843,10 @@ tanMp (double x)
   return y;
 }
 
-#ifdef NO_LONG_DOUBLE
-weak_alias (tan, tanl)
+#ifndef __tan
+weak_alias (__tan, tan)
+# ifdef NO_LONG_DOUBLE
+strong_alias (__tan, __tanl)
+weak_alias (__tanl, tanl)
+# endif
 #endif

sysdeps/x86_64/fpu/multiarch/s_atan-avx.c

@@ -1,4 +1,4 @@
-#define atan __atan_avx
+#define __atan __atan_avx
 #define __add __add_avx
 #define __dbl_mp __dbl_mp_avx
 #define __mul __mul_avx

sysdeps/x86_64/fpu/multiarch/s_atan-fma.c

@@ -1,4 +1,4 @@
-#define atan __atan_fma
+#define __atan __atan_fma
 #define __add __add_fma
 #define __dbl_mp __dbl_mp_fma
 #define __mpatan __mpatan_fma

sysdeps/x86_64/fpu/multiarch/s_atan-fma4.c

@@ -1,4 +1,4 @@
-#define atan __atan_fma4
+#define __atan __atan_fma4
 #define __add __add_fma4
 #define __dbl_mp __dbl_mp_fma4
 #define __mpatan __mpatan_fma4

sysdeps/x86_64/fpu/multiarch/s_atan.c

@@ -21,7 +21,8 @@ extern double __redirect_atan (double);
 #define SYMBOL_NAME atan
 #include "ifunc-avx-fma4.h"
 
-libc_ifunc_redirected (__redirect_atan, atan, IFUNC_SELECTOR ());
+libc_ifunc_redirected (__redirect_atan, __atan, IFUNC_SELECTOR ());
+weak_alias (__atan, atan)
 
-#define atan __atan_sse2
+#define __atan __atan_sse2
 #include <sysdeps/ieee754/dbl-64/s_atan.c>

sysdeps/x86_64/fpu/multiarch/s_tan-avx.c

@@ -1,4 +1,4 @@
-#define tan __tan_avx
+#define __tan __tan_avx
 #define __dbl_mp __dbl_mp_avx
 #define __sub __sub_avx
 #define SECTION __attribute__ ((section (".text.avx")))

sysdeps/x86_64/fpu/multiarch/s_tan-fma.c

@@ -1,4 +1,4 @@
-#define tan __tan_fma
+#define __tan __tan_fma
 #define __dbl_mp __dbl_mp_fma
 #define __mpranred __mpranred_fma
 #define __mptan __mptan_fma

sysdeps/x86_64/fpu/multiarch/s_tan-fma4.c

@@ -1,4 +1,4 @@
-#define tan __tan_fma4
+#define __tan __tan_fma4
 #define __dbl_mp __dbl_mp_fma4
 #define __mpranred __mpranred_fma4
 #define __mptan __mptan_fma4

sysdeps/x86_64/fpu/multiarch/s_tan.c

@@ -21,7 +21,8 @@ extern double __redirect_tan (double);
 #define SYMBOL_NAME tan
 #include "ifunc-avx-fma4.h"
 
-libc_ifunc_redirected (__redirect_tan, tan, IFUNC_SELECTOR ());
+libc_ifunc_redirected (__redirect_tan, __tan, IFUNC_SELECTOR ());
+weak_alias (__tan, tan)
 
-#define tan __tan_sse2
+#define __tan __tan_sse2
 #include <sysdeps/ieee754/dbl-64/s_tan.c>