Piotr Caban : msvcrt: Import rint implementation from musl.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: cba9981c473211ee53777dae70d82d3f80f92308
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=cba9981c473211ee53777dae70d82d3f80f92308

Author: Piotr Caban <piotr at codeweavers.com>
Date:   Mon May 10 20:11:34 2021 +0200

msvcrt: Import rint 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    | 33 ++++++++++++++++++++++++++++++++-
 dlls/msvcrt/unixlib.c | 13 -------------
 dlls/msvcrt/unixlib.h |  1 -
 include/config.h.in   |  3 ---
 6 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/configure b/configure
index 2a4a756c812..59248c28c99 100755
--- a/configure
+++ b/configure
@@ -19652,7 +19652,6 @@ for ac_func in \
 	remainderf \
 	remquo \
 	remquof \
-	rint \
 	rintf \
 	tgamma \
 	tgammaf \
diff --git a/configure.ac b/configure.ac
index 5578ee98edf..0c1ea608d7e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2692,7 +2692,6 @@ AC_CHECK_FUNCS(\
 	remainderf \
 	remquo \
 	remquof \
-	rint \
 	rintf \
 	tgamma \
 	tgammaf \
diff --git a/dlls/msvcrt/math.c b/dlls/msvcrt/math.c
index 95c83fcbcc9..c1702c5b810 100644
--- a/dlls/msvcrt/math.c
+++ b/dlls/msvcrt/math.c
@@ -87,6 +87,14 @@ static inline float fp_barrierf(float x)
     return y;
 }
 
+#if _MSVCR_VER>=120
+static inline double fp_barrier(double x)
+{
+    volatile double y = x;
+    return y;
+}
+#endif
+
 static inline double CDECL ret_nan( BOOL update_sw )
 {
     double x = 1.0;
@@ -4273,10 +4281,33 @@ float CDECL log2f(float x)
 
 /*********************************************************************
  *      rint (MSVCR120.@)
+ *
+ * Copied from musl: src/math/rint.c
  */
 double CDECL rint(double x)
 {
-    return unix_funcs->rint(x);
+    static const double toint = 1 / DBL_EPSILON;
+
+    ULONGLONG llx = *(ULONGLONG*)&x;
+    int e = llx >> 52 & 0x7ff;
+    int s = llx >> 63;
+    unsigned cw;
+    double y;
+
+    if (e >= 0x3ff+52)
+        return x;
+    cw = _controlfp(0, 0);
+    if ((cw & _MCW_PC) != _PC_53)
+        _controlfp(_PC_53, _MCW_PC);
+    if (s)
+        y = fp_barrier(x - toint) + toint;
+    else
+        y = fp_barrier(x + toint) - toint;
+    if ((cw & _MCW_PC) != _PC_53)
+        _controlfp(cw, _MCW_PC);
+    if (y == 0)
+        return s ? -0.0 : 0;
+    return y;
 }
 
 /*********************************************************************
diff --git a/dlls/msvcrt/unixlib.c b/dlls/msvcrt/unixlib.c
index 33c25ef8d40..f72fd0cc161 100644
--- a/dlls/msvcrt/unixlib.c
+++ b/dlls/msvcrt/unixlib.c
@@ -729,18 +729,6 @@ static float CDECL unix_remquof(float x, float y, int *quo)
 #endif
 }
 
-/*********************************************************************
- *      rint
- */
-static double CDECL unix_rint(double x)
-{
-#ifdef HAVE_RINT
-    return rint(x);
-#else
-    return x >= 0 ? floor(x + 0.5) : ceil(x - 0.5);
-#endif
-}
-
 /*********************************************************************
  *      rintf
  */
@@ -934,7 +922,6 @@ static const struct unix_funcs funcs =
     unix_remainderf,
     unix_remquo,
     unix_remquof,
-    unix_rint,
     unix_rintf,
     unix_sin,
     unix_sinf,
diff --git a/dlls/msvcrt/unixlib.h b/dlls/msvcrt/unixlib.h
index c96eda3c3a0..f5245cfb645 100644
--- a/dlls/msvcrt/unixlib.h
+++ b/dlls/msvcrt/unixlib.h
@@ -88,7 +88,6 @@ struct unix_funcs
     float           (CDECL *remainderf)(float x, float y);
     double          (CDECL *remquo)(double x, double y, int *quo);
     float           (CDECL *remquof)(float x, float y, int *quo);
-    double          (CDECL *rint)(double x);
     float           (CDECL *rintf)(float x);
     double          (CDECL *sin)(double x);
     float           (CDECL *sinf)(float x);
diff --git a/include/config.h.in b/include/config.h.in
index a0bc1b4b247..181cbc3d5aa 100644
--- a/include/config.h.in
+++ b/include/config.h.in
@@ -684,9 +684,6 @@
 /* Define to 1 if you have the `res_getservers' function. */
 #undef HAVE_RES_GETSERVERS
 
-/* Define to 1 if you have the `rint' function. */
-#undef HAVE_RINT
-
 /* Define to 1 if you have the `rintf' function. */
 #undef HAVE_RINTF