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authorRoland McGrath <roland@gnu.org>1996-03-05 21:41:30 +0000
committerRoland McGrath <roland@gnu.org>1996-03-05 21:41:30 +0000
commitf7eac6eb504f4baf13dbb4d26717942df050ebe6 (patch)
tree95ff129c06c7f6f246a5e2bfa489ba6382659d19 /sysdeps/libm-ieee754/k_tanf.c
parent1521668f2afae1dc2ef5d7ffaeb84353b36874dd (diff)
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Mon Mar 4 20:54:40 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
* Makeconfig ($(common-objpfx)config.make): Depend on config.h.in. Mon Mar 4 17:35:09 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu> * hurd/catch-signal.c (hurd_safe_memmove): New function. (hurd_safe_copyin, hurd_safe_copyout): New functions. * hurd/hurd/sigpreempt.h: Declare them. Sun Mar 3 08:43:44 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu> Replace math code with fdlibm from Sun as modified for netbsd by JT Conklin and Ian Taylor, including x86 FPU support. * sysdeps/libm-ieee754, sysdeps/libm-i387: New directories. * math/math_private.h: New file. * sysdeps/i386/fpu/Implies: New file. * sysdeps/ieee754/Implies: New file. * math/machine/asm.h, math/machine/endian.h: New files. * math/Makefile, math/math.h: Rewritten. * mathcalls.h, math/mathcalls.h: New file, broken out of math.h. * math/finite.c: File removed. * sysdeps/generic/Makefile [$(subdir)=math]: Frobnication removed. * math/test-math.c: Include errno.h and string.h. * sysdeps/unix/bsd/dirstream.h: File removed. * sysdeps/unix/bsd/readdir.c: File removed.
Diffstat (limited to 'sysdeps/libm-ieee754/k_tanf.c')
-rw-r--r--sysdeps/libm-ieee754/k_tanf.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/k_tanf.c b/sysdeps/libm-ieee754/k_tanf.c
new file mode 100644
index 0000000000..eb1a670939
--- /dev/null
+++ b/sysdeps/libm-ieee754/k_tanf.c
@@ -0,0 +1,101 @@
+/* k_tanf.c -- float version of k_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: k_tanf.c,v 1.4 1995/05/10 20:46:39 jtc Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+#ifdef __STDC__
+static const float
+#else
+static float
+#endif
+one = 1.0000000000e+00, /* 0x3f800000 */
+pio4 = 7.8539812565e-01, /* 0x3f490fda */
+pio4lo= 3.7748947079e-08, /* 0x33222168 */
+T[] = {
+ 3.3333334327e-01, /* 0x3eaaaaab */
+ 1.3333334029e-01, /* 0x3e088889 */
+ 5.3968254477e-02, /* 0x3d5d0dd1 */
+ 2.1869488060e-02, /* 0x3cb327a4 */
+ 8.8632395491e-03, /* 0x3c11371f */
+ 3.5920790397e-03, /* 0x3b6b6916 */
+ 1.4562094584e-03, /* 0x3abede48 */
+ 5.8804126456e-04, /* 0x3a1a26c8 */
+ 2.4646313977e-04, /* 0x398137b9 */
+ 7.8179444245e-05, /* 0x38a3f445 */
+ 7.1407252108e-05, /* 0x3895c07a */
+ -1.8558637748e-05, /* 0xb79bae5f */
+ 2.5907305826e-05, /* 0x37d95384 */
+};
+
+#ifdef __STDC__
+ float __kernel_tanf(float x, float y, int iy)
+#else
+ float __kernel_tanf(x, y, iy)
+ float x,y; int iy;
+#endif
+{
+ float z,r,v,w,s;
+ int32_t ix,hx;
+ GET_FLOAT_WORD(hx,x);
+ ix = hx&0x7fffffff; /* high word of |x| */
+ if(ix<0x31800000) /* x < 2**-28 */
+ {if((int)x==0) { /* generate inexact */
+ if((ix|(iy+1))==0) return one/fabsf(x);
+ else return (iy==1)? x: -one/x;
+ }
+ }
+ if(ix>=0x3f2ca140) { /* |x|>=0.6744 */
+ if(hx<0) {x = -x; y = -y;}
+ z = pio4-x;
+ w = pio4lo-y;
+ x = z+w; y = 0.0;
+ }
+ z = x*x;
+ w = z*z;
+ /* Break x^5*(T[1]+x^2*T[2]+...) into
+ * x^5(T[1]+x^4*T[3]+...+x^20*T[11]) +
+ * x^5(x^2*(T[2]+x^4*T[4]+...+x^22*[T12]))
+ */
+ r = T[1]+w*(T[3]+w*(T[5]+w*(T[7]+w*(T[9]+w*T[11]))));
+ v = z*(T[2]+w*(T[4]+w*(T[6]+w*(T[8]+w*(T[10]+w*T[12])))));
+ s = z*x;
+ r = y + z*(s*(r+v)+y);
+ r += T[0]*s;
+ w = x+r;
+ if(ix>=0x3f2ca140) {
+ v = (float)iy;
+ return (float)(1-((hx>>30)&2))*(v-(float)2.0*(x-(w*w/(w+v)-r)));
+ }
+ if(iy==1) return w;
+ else { /* if allow error up to 2 ulp,
+ simply return -1.0/(x+r) here */
+ /* compute -1.0/(x+r) accurately */
+ float a,t;
+ int32_t i;
+ z = w;
+ GET_FLOAT_WORD(i,z);
+ SET_FLOAT_WORD(z,i&0xfffff000);
+ v = r-(z - x); /* z+v = r+x */
+ t = a = -(float)1.0/w; /* a = -1.0/w */
+ GET_FLOAT_WORD(i,t);
+ SET_FLOAT_WORD(t,i&0xfffff000);
+ s = (float)1.0+t*z;
+ return t+a*(s+t*v);
+ }
+}