msvcrt: Import frexpf implementation from musl.

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

dlls/msvcrt/math.c

@@ -1611,10 +1611,28 @@ float CDECL floorf( float x )
 
 /*********************************************************************
  *      frexpf (MSVCRT.@)
+ *
+ * Copied from musl: src/math/frexpf.c
  */
-float CDECL frexpf( float x, int *exp )
+float CDECL frexpf( float x, int *e )
 {
-  return unix_funcs->frexpf( x, exp );
+    UINT32 ux = *(UINT32*)&x;
+    int ee = ux >> 23 & 0xff;
+
+    if (!ee) {
+        if (x) {
+            x = frexpf(x * 0x1p64, e);
+            *e -= 64;
+        } else *e = 0;
+        return x;
+    } else if (ee == 0xff) {
+        return x;
+    }
+
+    *e = ee - 0x7e;
+    ux &= 0x807ffffful;
+    ux |= 0x3f000000ul;
+    return *(float*)&ux;
 }
 
 /*********************************************************************

dlls/msvcrt/unixlib.c

@@ -94,14 +94,6 @@ static float CDECL unix_fmaf( float x, float y, float z )
 #endif
 }
 
-/*********************************************************************
- *      frexpf
- */
-static float CDECL unix_frexpf( float x, int *exp )
-{
-    return frexpf( x, exp );
-}
-
 /*********************************************************************
  *      hypot
  */
@@ -273,7 +265,6 @@ static const struct unix_funcs funcs =
     unix_exp2,
     unix_exp2f,
     unix_fmaf,
-    unix_frexpf,
     unix_hypot,
     unix_hypotf,
     unix_lgamma,

dlls/msvcrt/unixlib.h

@@ -28,7 +28,6 @@ struct unix_funcs
     double          (CDECL *exp2)(double x);
     float           (CDECL *exp2f)(float x);
     float           (CDECL *fmaf)(float x, float y, float z);
-    float           (CDECL *frexpf)(float x, int *exp);
     double          (CDECL *hypot)(double x, double y);
     float           (CDECL *hypotf)(float x, float y);
     double          (CDECL *lgamma)(double x);