msvcrt: Import acosh implementation from musl.

configure

@@ -19616,7 +19616,6 @@ $as_echo "#define HAVE_ISNAN 1" >>confdefs.h
 fi
 
 for ac_func in \
-	acosh \
 	asinh \
 	asinhf \
 	atanh \

configure.ac

@@ -2656,7 +2656,6 @@ then
 fi
 
 AC_CHECK_FUNCS(\
-	acosh \
 	asinh \
 	asinhf \
 	atanh \

dlls/msvcrt/math.c

@@ -6585,16 +6585,26 @@ float CDECL asinhf(float x)
 
 /*********************************************************************
  *      acosh (MSVCR120.@)
+ *
+ * Copied from musl: src/math/acosh.c
  */
 double CDECL acosh(double x)
 {
+    int e = *(UINT64*)&x >> 52 & 0x7ff;
+
     if (x < 1)
     {
         *_errno() = EDOM;
         feraiseexcept(FE_INVALID);
         return NAN;
     }
-    return unix_funcs->acosh( x );
+
+    if (e < 0x3ff + 1) /* |x| < 2, up to 2ulp error in [1,1.125] */
+        return log1p(x - 1 + sqrt((x - 1) * (x - 1) + 2 * (x - 1)));
+    if (e < 0x3ff + 26) /* |x| < 0x1p26 */
+        return log(2 * x - 1 / (x + sqrt(x * x - 1)));
+    /* |x| >= 0x1p26 or nan */
+    return log(x) + 0.693147180559945309417232121458176568;
 }
 
 /*********************************************************************

dlls/msvcrt/unixlib.c

@@ -43,19 +43,6 @@
 WINE_DEFAULT_DEBUG_CHANNEL(msvcrt);
 
 /*********************************************************************
- *      acosh
- */
-static double CDECL unix_acosh(double x)
-{
-#ifdef HAVE_ACOSH
-    return acosh(x);
-#else
-    if (!isfinite(x*x)) return log(2) + log(x);
-    return log(x + sqrt(x*x-1));
-#endif
-}
-
-/*********************************************************************
  *      asinh
  */
 static double CDECL unix_asinh(double x)
@@ -435,7 +422,6 @@ static float CDECL unix_tgammaf(float x)
 
 static const struct unix_funcs funcs =
 {
-    unix_acosh,
     unix_asinh,
     unix_asinhf,
     unix_atanh,

dlls/msvcrt/unixlib.h

@@ -23,7 +23,6 @@
 
 struct unix_funcs
 {
-    double          (CDECL *acosh)(double x);
     double          (CDECL *asinh)(double x);
     float           (CDECL *asinhf)(float x);
     double          (CDECL *atanh)(double x);

include/config.h.in

@@ -9,9 +9,6 @@
 /* Define to the file extension for executables. */
 #undef EXEEXT
 
-/* Define to 1 if you have the `acosh' function. */
-#undef HAVE_ACOSH
-
 /* Define to 1 if you have the <alias.h> header file. */
 #undef HAVE_ALIAS_H