summaryrefslogtreecommitdiffstats
path: root/libm/src/s_sinf.c
diff options
context:
space:
mode:
Diffstat (limited to 'libm/src/s_sinf.c')
-rw-r--r--libm/src/s_sinf.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/libm/src/s_sinf.c b/libm/src/s_sinf.c
new file mode 100644
index 0000000..9dc3cae
--- /dev/null
+++ b/libm/src/s_sinf.c
@@ -0,0 +1,82 @@
+/* s_sinf.c -- float version of s_sin.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ * Optimized by Bruce D. Evans.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#ifndef lint
+static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_sinf.c,v 1.14 2005/11/28 06:15:10 bde Exp $";
+#endif
+
+#include "math.h"
+#define INLINE_KERNEL_COSDF
+#define INLINE_KERNEL_SINDF
+#include "math_private.h"
+#include "k_cosf.c"
+#include "k_sinf.c"
+
+/* Small multiples of pi/2 rounded to double precision. */
+static const double
+s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
+s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
+s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
+s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
+
+float
+sinf(float x)
+{
+ float y[2];
+ int32_t n, hx, ix;
+
+ GET_FLOAT_WORD(hx,x);
+ ix = hx & 0x7fffffff;
+
+ if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
+ if(ix<0x39800000) /* |x| < 2**-12 */
+ if(((int)x)==0) return x; /* x with inexact if x != 0 */
+ return __kernel_sindf(x);
+ }
+ if(ix<=0x407b53d1) { /* |x| ~<= 5*pi/4 */
+ if(ix<=0x4016cbe3) { /* |x| ~<= 3pi/4 */
+ if(hx>0)
+ return __kernel_cosdf(x - s1pio2);
+ else
+ return -__kernel_cosdf(x + s1pio2);
+ } else
+ return __kernel_sindf((hx > 0 ? s2pio2 : -s2pio2) - x);
+ }
+ if(ix<=0x40e231d5) { /* |x| ~<= 9*pi/4 */
+ if(ix<=0x40afeddf) { /* |x| ~<= 7*pi/4 */
+ if(hx>0)
+ return -__kernel_cosdf(x - s3pio2);
+ else
+ return __kernel_cosdf(x + s3pio2);
+ } else
+ return __kernel_sindf(x + (hx > 0 ? -s4pio2 : s4pio2));
+ }
+
+ /* sin(Inf or NaN) is NaN */
+ else if (ix>=0x7f800000) return x-x;
+
+ /* general argument reduction needed */
+ else {
+ n = __ieee754_rem_pio2f(x,y);
+ switch(n&3) {
+ case 0: return __kernel_sindf((double)y[0]+y[1]);
+ case 1: return __kernel_cosdf((double)y[0]+y[1]);
+ case 2: return __kernel_sindf(-(double)y[0]-y[1]);
+ default:
+ return -__kernel_cosdf((double)y[0]+y[1]);
+ }
+ }
+}