msvcrt: Import nexttowardf implementation from musl.

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

configure

@@ -19640,7 +19640,6 @@ for ac_func in \
 	log1pf \
 	log2 \
 	log2f \
-	nexttowardf \
 	remainder \
 	remainderf \
 	remquo \

configure.ac

@@ -2680,7 +2680,6 @@ AC_CHECK_FUNCS(\
 	log1pf \
 	log2 \
 	log2f \
-	nexttowardf \
 	remainder \
 	remainderf \
 	remquo \

dlls/msvcrt/math.c

@@ -3492,13 +3492,44 @@ double CDECL MSVCRT_nexttoward(double num, double next)
 
 /*********************************************************************
  *              nexttowardf (MSVCR120.@)
+ *
+ * Copied from musl: src/math/nexttowardf.c
  */
-float CDECL MSVCRT_nexttowardf(float num, double next)
+float CDECL MSVCRT_nexttowardf(float x, double y)
 {
-    float ret = unix_funcs->nexttowardf( num, next );
-    if (!(_fpclass(ret) & (_FPCLASS_PN | _FPCLASS_NN
-            | _FPCLASS_SNAN | _FPCLASS_QNAN)) && !isinf(num))
-    {
+    unsigned int ix = *(unsigned int*)&x;
+    unsigned int e;
+    float ret;
+
+    if (isnan(x) || isnan(y))
+        return x + y;
+    if (x == y)
+        return y;
+    if (x == 0) {
+        ix = 1;
+        if (signbit(y))
+            ix |= 0x80000000;
+    } else if (x < y) {
+        if (signbit(x))
+            ix--;
+        else
+            ix++;
+    } else {
+        if (signbit(x))
+            ix++;
+        else
+            ix--;
+    }
+    e = ix & 0x7f800000;
+    /* raise overflow if ix is infinite and x is finite */
+    if (e == 0x7f800000) {
+        fp_barrierf(x + x);
+        *_errno() = ERANGE;
+    }
+    ret = *(float*)&ix;
+    /* raise underflow if ret is subnormal or zero */
+    if (e == 0) {
+        fp_barrierf(x * x + ret * ret);
         *_errno() = ERANGE;
     }
     return ret;

dlls/msvcrt/unixlib.c

@@ -547,19 +547,6 @@ static float CDECL unix_modff( float x, float *iptr )
     return modff( x, iptr );
 }
 
-/*********************************************************************
- *      nexttowardf
- */
-static float CDECL unix_nexttowardf(float num, double next)
-{
-#ifdef HAVE_NEXTTOWARDF
-    return nexttowardf(num, next);
-#else
-    FIXME("not implemented\n");
-    return 0;
-#endif
-}
-
 /*********************************************************************
  *      pow
  */
@@ -793,7 +780,6 @@ static const struct unix_funcs funcs =
     unix_logbf,
     unix_modf,
     unix_modff,
-    unix_nexttowardf,
     unix_pow,
     unix_powf,
     unix_remainder,

dlls/msvcrt/unixlib.h

@@ -72,7 +72,6 @@ struct unix_funcs
     float           (CDECL *logbf)(float x);
     double          (CDECL *modf)(double x, double *iptr);
     float           (CDECL *modff)(float x, float *iptr);
-    float           (CDECL *nexttowardf)(float x, double y);
     double          (CDECL *pow)(double x, double y);
     float           (CDECL *powf)(float x, float y);
     double          (CDECL *remainder)(double x, double y);

include/config.h.in

@@ -567,9 +567,6 @@
 /* Define to 1 if you have the <net/route.h> header file. */
 #undef HAVE_NET_ROUTE_H
 
-/* Define to 1 if you have the `nexttowardf' function. */
-#undef HAVE_NEXTTOWARDF
-
 /* Define to 1 if `_msg_ptr' is a member of `ns_msg'. */
 #undef HAVE_NS_MSG__MSG_PTR