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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_rem_pio2f.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_rem_pio2f.c')
-rw-r--r--sysdeps/libm-ieee754/k_rem_pio2f.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/k_rem_pio2f.c b/sysdeps/libm-ieee754/k_rem_pio2f.c
new file mode 100644
index 0000000000..2783480fcb
--- /dev/null
+++ b/sysdeps/libm-ieee754/k_rem_pio2f.c
@@ -0,0 +1,213 @@
+/* k_rem_pio2f.c -- float version of k_rem_pio2.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_rem_pio2f.c,v 1.4 1995/05/10 20:46:28 jtc Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+
+/* In the float version, the input parameter x contains 8 bit
+   integers, not 24 bit integers.  113 bit precision is not supported.  */
+
+#ifdef __STDC__
+static const int init_jk[] = {4,7,9}; /* initial value for jk */
+#else
+static int init_jk[] = {4,7,9}; 
+#endif
+
+#ifdef __STDC__
+static const float PIo2[] = {
+#else
+static float PIo2[] = {
+#endif
+  1.5703125000e+00, /* 0x3fc90000 */
+  4.5776367188e-04, /* 0x39f00000 */
+  2.5987625122e-05, /* 0x37da0000 */
+  7.5437128544e-08, /* 0x33a20000 */
+  6.0026650317e-11, /* 0x2e840000 */
+  7.3896444519e-13, /* 0x2b500000 */
+  5.3845816694e-15, /* 0x27c20000 */
+  5.6378512969e-18, /* 0x22d00000 */
+  8.3009228831e-20, /* 0x1fc40000 */
+  3.2756352257e-22, /* 0x1bc60000 */
+  6.3331015649e-25, /* 0x17440000 */
+};
+
+#ifdef __STDC__
+static const float			
+#else
+static float			
+#endif
+zero   = 0.0,
+one    = 1.0,
+two8   =  2.5600000000e+02, /* 0x43800000 */
+twon8  =  3.9062500000e-03; /* 0x3b800000 */
+
+#ifdef __STDC__
+	int __kernel_rem_pio2f(float *x, float *y, int e0, int nx, int prec, const int32_t *ipio2) 
+#else
+	int __kernel_rem_pio2f(x,y,e0,nx,prec,ipio2) 	
+	float x[], y[]; int e0,nx,prec; int32_t ipio2[];
+#endif
+{
+	int32_t jz,jx,jv,jp,jk,carry,n,iq[20],i,j,k,m,q0,ih;
+	float z,fw,f[20],fq[20],q[20];
+
+    /* initialize jk*/
+	jk = init_jk[prec];
+	jp = jk;
+
+    /* determine jx,jv,q0, note that 3>q0 */
+	jx =  nx-1;
+	jv = (e0-3)/8; if(jv<0) jv=0;
+	q0 =  e0-8*(jv+1);
+
+    /* set up f[0] to f[jx+jk] where f[jx+jk] = ipio2[jv+jk] */
+	j = jv-jx; m = jx+jk;
+	for(i=0;i<=m;i++,j++) f[i] = (j<0)? zero : (float) ipio2[j];
+
+    /* compute q[0],q[1],...q[jk] */
+	for (i=0;i<=jk;i++) {
+	    for(j=0,fw=0.0;j<=jx;j++) fw += x[j]*f[jx+i-j]; q[i] = fw;
+	}
+
+	jz = jk;
+recompute:
+    /* distill q[] into iq[] reversingly */
+	for(i=0,j=jz,z=q[jz];j>0;i++,j--) {
+	    fw    =  (float)((int32_t)(twon8* z));
+	    iq[i] =  (int32_t)(z-two8*fw);
+	    z     =  q[j-1]+fw;
+	}
+
+    /* compute n */
+	z  = __scalbnf(z,q0);		/* actual value of z */
+	z -= (float)8.0*__floorf(z*(float)0.125);	/* trim off integer >= 8 */
+	n  = (int32_t) z;
+	z -= (float)n;
+	ih = 0;
+	if(q0>0) {	/* need iq[jz-1] to determine n */
+	    i  = (iq[jz-1]>>(8-q0)); n += i;
+	    iq[jz-1] -= i<<(8-q0);
+	    ih = iq[jz-1]>>(7-q0);
+	} 
+	else if(q0==0) ih = iq[jz-1]>>8;
+	else if(z>=(float)0.5) ih=2;
+
+	if(ih>0) {	/* q > 0.5 */
+	    n += 1; carry = 0;
+	    for(i=0;i<jz ;i++) {	/* compute 1-q */
+		j = iq[i];
+		if(carry==0) {
+		    if(j!=0) {
+			carry = 1; iq[i] = 0x100- j;
+		    }
+		} else  iq[i] = 0xff - j;
+	    }
+	    if(q0>0) {		/* rare case: chance is 1 in 12 */
+	        switch(q0) {
+	        case 1:
+	    	   iq[jz-1] &= 0x7f; break;
+	    	case 2:
+	    	   iq[jz-1] &= 0x3f; break;
+	        }
+	    }
+	    if(ih==2) {
+		z = one - z;
+		if(carry!=0) z -= __scalbnf(one,q0);
+	    }
+	}
+
+    /* check if recomputation is needed */
+	if(z==zero) {
+	    j = 0;
+	    for (i=jz-1;i>=jk;i--) j |= iq[i];
+	    if(j==0) { /* need recomputation */
+		for(k=1;iq[jk-k]==0;k++);   /* k = no. of terms needed */
+
+		for(i=jz+1;i<=jz+k;i++) {   /* add q[jz+1] to q[jz+k] */
+		    f[jx+i] = (float) ipio2[jv+i];
+		    for(j=0,fw=0.0;j<=jx;j++) fw += x[j]*f[jx+i-j];
+		    q[i] = fw;
+		}
+		jz += k;
+		goto recompute;
+	    }
+	}
+
+    /* chop off zero terms */
+	if(z==(float)0.0) {
+	    jz -= 1; q0 -= 8;
+	    while(iq[jz]==0) { jz--; q0-=8;}
+	} else { /* break z into 8-bit if necessary */
+	    z = __scalbnf(z,-q0);
+	    if(z>=two8) { 
+		fw = (float)((int32_t)(twon8*z));
+		iq[jz] = (int32_t)(z-two8*fw);
+		jz += 1; q0 += 8;
+		iq[jz] = (int32_t) fw;
+	    } else iq[jz] = (int32_t) z ;
+	}
+
+    /* convert integer "bit" chunk to floating-point value */
+	fw = __scalbnf(one,q0);
+	for(i=jz;i>=0;i--) {
+	    q[i] = fw*(float)iq[i]; fw*=twon8;
+	}
+
+    /* compute PIo2[0,...,jp]*q[jz,...,0] */
+	for(i=jz;i>=0;i--) {
+	    for(fw=0.0,k=0;k<=jp&&k<=jz-i;k++) fw += PIo2[k]*q[i+k];
+	    fq[jz-i] = fw;
+	}
+
+    /* compress fq[] into y[] */
+	switch(prec) {
+	    case 0:
+		fw = 0.0;
+		for (i=jz;i>=0;i--) fw += fq[i];
+		y[0] = (ih==0)? fw: -fw; 
+		break;
+	    case 1:
+	    case 2:
+		fw = 0.0;
+		for (i=jz;i>=0;i--) fw += fq[i]; 
+		y[0] = (ih==0)? fw: -fw; 
+		fw = fq[0]-fw;
+		for (i=1;i<=jz;i++) fw += fq[i];
+		y[1] = (ih==0)? fw: -fw; 
+		break;
+	    case 3:	/* painful */
+		for (i=jz;i>0;i--) {
+		    fw      = fq[i-1]+fq[i]; 
+		    fq[i]  += fq[i-1]-fw;
+		    fq[i-1] = fw;
+		}
+		for (i=jz;i>1;i--) {
+		    fw      = fq[i-1]+fq[i]; 
+		    fq[i]  += fq[i-1]-fw;
+		    fq[i-1] = fw;
+		}
+		for (fw=0.0,i=jz;i>=2;i--) fw += fq[i]; 
+		if(ih==0) {
+		    y[0] =  fq[0]; y[1] =  fq[1]; y[2] =  fw;
+		} else {
+		    y[0] = -fq[0]; y[1] = -fq[1]; y[2] = -fw;
+		}
+	}
+	return n&7;
+}