msvcrt: Import cbrtf implementation from musl.

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

configure

@@ -19623,7 +19623,6 @@ for ac_func in \
 	atanh \
 	atanhf \
 	cbrt \
-	cbrtf \
 	erf \
 	erfc \
 	erfcf \

configure.ac

@@ -2663,7 +2663,6 @@ AC_CHECK_FUNCS(\
 	atanh \
 	atanhf \
 	cbrt \
-	cbrtf \
 	erf \
 	erfc \
 	erfcf \

dlls/msvcrt/math.c

@@ -4505,10 +4505,38 @@ double CDECL cbrt(double x)
 
 /*********************************************************************
  *      cbrtf (MSVCR120.@)
+ *
+ * Copied from musl: src/math/cbrtf.c
  */
 float CDECL cbrtf(float x)
 {
-    return unix_funcs->cbrtf( x );
+    static const unsigned B1 = 709958130, B2 = 642849266;
+
+    double r,T;
+    union {float f; UINT32 i;} u = {x};
+    UINT32 hx = u.i & 0x7fffffff;
+
+    if (hx >= 0x7f800000)
+        return x + x;
+
+    if (hx < 0x00800000) {  /* zero or subnormal? */
+        if (hx == 0)
+            return x;
+        u.f = x * 0x1p24f;
+        hx = u.i & 0x7fffffff;
+        hx = hx / 3 + B2;
+    } else
+        hx = hx / 3 + B1;
+    u.i &= 0x80000000;
+    u.i |= hx;
+
+    T = u.f;
+    r = T * T * T;
+    T = T * (x + x + r) / (x + r + r);
+
+    r = T * T * T;
+    T = T * (x + x + r) / (x + r + r);
+    return T;
 }
 
 /*********************************************************************

dlls/msvcrt/unixlib.c

@@ -133,18 +133,6 @@ static double CDECL unix_cbrt(double x)
 #endif
 }
 
-/*********************************************************************
- *      cbrtf
- */
-static float CDECL unix_cbrtf(float x)
-{
-#ifdef HAVE_CBRTF
-    return cbrtf(x);
-#else
-    return unix_cbrt(x);
-#endif
-}
-
 /*********************************************************************
  *      ceil
  */
@@ -738,7 +726,6 @@ static const struct unix_funcs funcs =
     unix_atanh,
     unix_atanhf,
     unix_cbrt,
-    unix_cbrtf,
     unix_ceil,
     unix_ceilf,
     unix_cos,

dlls/msvcrt/unixlib.h

@@ -30,7 +30,6 @@ struct unix_funcs
     double          (CDECL *atanh)(double x);
     float           (CDECL *atanhf)(float x);
     double          (CDECL *cbrt)(double x);
-    float           (CDECL *cbrtf)(float x);
     double          (CDECL *ceil)(double x);
     float           (CDECL *ceilf)(float x);
     double          (CDECL *cos)(double x);

include/config.h.in

@@ -70,9 +70,6 @@
 /* Define to 1 if you have the `cbrt' function. */
 #undef HAVE_CBRT
 
-/* Define to 1 if you have the `cbrtf' function. */
-#undef HAVE_CBRTF
-
 /* Define to 1 if you have the `clock_gettime' function. */
 #undef HAVE_CLOCK_GETTIME