msvcrt: Use the asinf() implementation from the bundled musl library.

dlls/msvcrt/math.c

@@ -290,61 +290,6 @@ int CDECL _isnanf( float num )
     return (u.i & 0x7fffffff) > 0x7f800000;
 }
 
-static float asinf_R(float z)
-{
-    /* coefficients for R(x^2) */
-    static const float p1 = 1.66666672e-01,
-                 p2 = -5.11644611e-02,
-                 p3 = -1.21124933e-02,
-                 p4 = -3.58742251e-03,
-                 q1 = -7.56982703e-01;
-
-    float p, q;
-    p = z * (p1 + z * (p2 + z * (p3 + z * p4)));
-    q = 1.0f + z * q1;
-    return p / q;
-}
-
-/*********************************************************************
- *      asinf (MSVCRT.@)
- *
- * Copied from musl: src/math/asinf.c
- */
-float CDECL asinf( float x )
-{
-    static const double pio2 = 1.570796326794896558e+00;
-    static const float pio4_hi = 0.785398125648;
-    static const float pio2_lo = 7.54978941586e-08;
-
-    float s, z, f, c;
-    unsigned int hx, ix;
-
-    hx = *(unsigned int*)&x;
-    ix = hx & 0x7fffffff;
-    if (ix >= 0x3f800000) {  /* |x| >= 1 */
-        if (ix == 0x3f800000)  /* |x| == 1 */
-            return x * pio2 + 7.5231638453e-37;  /* asin(+-1) = +-pi/2 with inexact */
-        if (isnan(x)) return x;
-        return math_error(_DOMAIN, "asinf", x, 0, 0 / (x - x));
-    }
-    if (ix < 0x3f000000) {  /* |x| < 0.5 */
-        /* if 0x1p-126 <= |x| < 0x1p-12, avoid raising underflow */
-        if (ix < 0x39800000 && ix >= 0x00800000)
-            return x;
-        return x + x * asinf_R(x * x);
-    }
-    /* 1 > |x| >= 0.5 */
-    z = (1 - fabsf(x)) * 0.5f;
-    s = sqrtf(z);
-    /* f+c = sqrt(z) */
-    *(unsigned int*)&f = *(unsigned int*)&s & 0xffff0000;
-    c = (z - f * f) / (s + f);
-    x = pio4_hi - (2 * s * asinf_R(z) - (pio2_lo - 2 * c) - (pio4_hi - 2 * f));
-    if (hx >> 31)
-        return -x;
-    return x;
-}
-
 /*********************************************************************
  *      atanf (MSVCRT.@)
  *

libs/musl/src/math/asinf.c

@@ -18,24 +18,26 @@ static const double
 pio2 = 1.570796326794896558e+00;
 
 static const float
+pio4_hi = 0.785398125648,
+pio2_lo = 7.54978941586e-08,
 /* coefficients for R(x^2) */
-pS0 =  1.6666586697e-01,
-pS1 = -4.2743422091e-02,
-pS2 = -8.6563630030e-03,
-qS1 = -7.0662963390e-01;
+pS0 =  1.66666672e-01,
+pS1 = -5.11644611e-02,
+pS2 = -1.21124933e-02,
+pS3 = -3.58742251e-03,
+qS1 = -7.56982703e-01;
 
 static float R(float z)
 {
 	float_t p, q;
-	p = z*(pS0+z*(pS1+z*pS2));
+	p = z*(pS0+z*(pS1+z*(pS2+z*pS3)));
 	q = 1.0f+z*qS1;
 	return p/q;
 }
 
 float __cdecl asinf(float x)
 {
-	double s;
-	float z;
+	float s, z, f, c;
 	uint32_t hx,ix;
 
 	GET_FLOAT_WORD(hx, x);
@@ -43,7 +45,8 @@ float __cdecl asinf(float x)
 	if (ix >= 0x3f800000) {  /* |x| >= 1 */
 		if (ix == 0x3f800000)  /* |x| == 1 */
 			return x*pio2 + 0x1p-120f;  /* asin(+-1) = +-pi/2 with inexact */
-		return 0/(x-x);  /* asin(|x|>1) is NaN */
+		if (isnan(x)) return x;
+		return math_error(_DOMAIN, "asinf", x, 0, 0 / (x - x));
 	}
 	if (ix < 0x3f000000) {  /* |x| < 0.5 */
 		/* if 0x1p-126 <= |x| < 0x1p-12, avoid raising underflow */
@@ -53,8 +56,11 @@ float __cdecl asinf(float x)
 	}
 	/* 1 > |x| >= 0.5 */
 	z = (1 - fabsf(x))*0.5f;
-	s = sqrt(z);
-	x = pio2 - 2*(s+s*R(z));
+	s = sqrtf(z);
+	/* f+c = sqrt(z) */
+	*(unsigned int*)&f = *(unsigned int*)&s & 0xffff0000;
+	c = (z - f * f) / (s + f);
+	x = pio4_hi - (2*s*R(z) - (pio2_lo - 2*c) - (pio4_hi - 2*f));
 	if (hx >> 31)
 		return -x;
 	return x;