summary refs log tree commit diff
path: root/sysdeps/libm-ieee754/s_tanf.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/libm-ieee754/s_tanf.c')
-rw-r--r--sysdeps/libm-ieee754/s_tanf.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_tanf.c b/sysdeps/libm-ieee754/s_tanf.c
new file mode 100644
index 0000000000..e8f6016c32
--- /dev/null
+++ b/sysdeps/libm-ieee754/s_tanf.c
@@ -0,0 +1,49 @@
+/* s_tanf.c -- float version of s_tan.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: s_tanf.c,v 1.4 1995/05/10 20:48:20 jtc Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+	float __tanf(float x)
+#else
+	float __tanf(x)
+	float x;
+#endif
+{
+	float y[2],z=0.0;
+	int32_t n, ix;
+
+	GET_FLOAT_WORD(ix,x);
+
+    /* |x| ~< pi/4 */
+	ix &= 0x7fffffff;
+	if(ix <= 0x3f490fda) return __kernel_tanf(x,z,1);
+
+    /* tan(Inf or NaN) is NaN */
+	else if (ix>=0x7f800000) return x-x;		/* NaN */
+
+    /* argument reduction needed */
+	else {
+	    n = __ieee754_rem_pio2f(x,y);
+	    return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /*   1 -- n even
+							      -1 -- n odd */
+	}
+}
+weak_alias (__tanf, tanf)