Piotr Caban : msvcrt: Import acosh implementation from musl.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: bc9105e238a076da6e22e0df77a6de6a6f3cd0a7
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=bc9105e238a076da6e22e0df77a6de6a6f3cd0a7

Author: Piotr Caban <piotr at codeweavers.com>
Date:   Tue May 25 15:21:10 2021 +0200

msvcrt: Import acosh implementation from musl.

Signed-off-by: Piotr Caban <piotr at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 configure             |  1 -
 configure.ac          |  1 -
 dlls/msvcrt/math.c    | 12 +++++++++++-
 dlls/msvcrt/unixlib.c | 14 --------------
 dlls/msvcrt/unixlib.h |  1 -
 include/config.h.in   |  3 ---
 6 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/configure b/configure
index 3f1fc453e34..a0510d8a36f 100755
--- a/configure
+++ b/configure
@@ -19616,7 +19616,6 @@ $as_echo "#define HAVE_ISNAN 1" >>confdefs.h
 fi
 
 for ac_func in \
-	acosh \
 	asinh \
 	asinhf \
 	atanh \
diff --git a/configure.ac b/configure.ac
index e1989cc2868..0dd919f1a2c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2656,7 +2656,6 @@ then
 fi
 
 AC_CHECK_FUNCS(\
-	acosh \
 	asinh \
 	asinhf \
 	atanh \
diff --git a/dlls/msvcrt/math.c b/dlls/msvcrt/math.c
index 01c50800567..01c0c053aa5 100644
--- a/dlls/msvcrt/math.c
+++ b/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;
 }
 
 /*********************************************************************
diff --git a/dlls/msvcrt/unixlib.c b/dlls/msvcrt/unixlib.c
index efd3021aa59..f51739cf0c9 100644
--- a/dlls/msvcrt/unixlib.c
+++ b/dlls/msvcrt/unixlib.c
@@ -42,19 +42,6 @@
 
 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
  */
@@ -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,
diff --git a/dlls/msvcrt/unixlib.h b/dlls/msvcrt/unixlib.h
index 2f171339d30..b4275e3750b 100644
--- a/dlls/msvcrt/unixlib.h
+++ b/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);
diff --git a/include/config.h.in b/include/config.h.in
index b94337818ca..ab6c2bc3381 100644
--- a/include/config.h.in
+++ b/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