msvcrt: Use the floor()/floorf() implementation from the bundled musl library.

dlls/msvcrt/math.c

@@ -1426,35 +1426,6 @@ float CDECL ceilf( float x )
     return u.f;
 }
 
-/*********************************************************************
- *      floorf (MSVCRT.@)
- *
- * Copied from musl: src/math/floorf.c
- */
-float CDECL floorf( float x )
-{
-    union {float f; UINT32 i;} u = {x};
-    int e = (int)(u.i >> 23 & 0xff) - 0x7f;
-    UINT32 m;
-
-    if (e >= 23)
-        return x;
-    if (e >= 0) {
-        m = 0x007fffff >> e;
-        if ((u.i & m) == 0)
-            return x;
-        if (u.i >> 31)
-            u.i += m;
-        u.i &= ~m;
-    } else {
-        if (u.i >> 31 == 0)
-            return 0;
-        else if (u.i << 1)
-            return -1;
-    }
-    return u.f;
-}
-
 #endif
 
 /*********************************************************************
@@ -3260,35 +3231,6 @@ double CDECL ceil( double x )
     return u.f;
 }
 
-/*********************************************************************
- *		floor (MSVCRT.@)
- *
- * Based on musl: src/math/floorf.c
- */
-double CDECL floor( double x )
-{
-    union {double f; UINT64 i;} u = {x};
-    int e = (int)(u.i >> 52 & 0x7ff) - 0x3ff;
-    UINT64 m;
-
-    if (e >= 52)
-        return x;
-    if (e >= 0) {
-        m = 0x000fffffffffffffULL >> e;
-        if ((u.i & m) == 0)
-            return x;
-        if (u.i >> 63)
-            u.i += m;
-        u.i &= ~m;
-    } else {
-        if (u.i >> 63 == 0)
-            return 0;
-        else if (u.i << 1)
-            return -1;
-    }
-    return u.f;
-}
-
 #if defined(__i386__) || defined(__x86_64__)
 static void _setfp_sse( unsigned int *cw, unsigned int cw_mask,
         unsigned int *sw, unsigned int sw_mask )

libs/musl/src/math/floor.c

@@ -5,27 +5,27 @@
 #elif FLT_EVAL_METHOD==2
 #define EPS LDBL_EPSILON
 #endif
-static const double_t toint = 1/EPS;
 
 double __cdecl floor(double x)
 {
 	union {double f; uint64_t i;} u = {x};
-	int e = u.i >> 52 & 0x7ff;
+	int e = (u.i >> 52 & 0x7ff) - 0x3ff;
 	double_t y;
 
-	if (e >= 0x3ff+52 || x == 0)
+	if (e >= 52)
 		return x;
-	/* y = int(x) - x, where int(x) is an integer neighbor of x */
-	if (u.i >> 63)
-		y = x - toint + toint - x;
-	else
-		y = x + toint - toint - x;
-	/* special case because of non-nearest rounding modes */
-	if (e <= 0x3ff-1) {
-		FORCE_EVAL(y);
-		return u.i >> 63 ? -1 : 0;
+	if (e >= 0) {
+		uint64_t m = 0x000fffffffffffffULL >> e;
+		if ((u.i & m) == 0)
+			return x;
+		if (u.i >> 63)
+			u.i += m;
+		u.i &= ~m;
+	} else {
+		if (u.i >> 63 == 0)
+			return 0;
+		if (u.i << 1)
+			return -1;
 	}
-	if (y > 0)
-		return x + y - 1;
-	return x + y;
+	return u.f;
 }