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authorUlrich Drepper <drepper@redhat.com>1997-03-27 01:59:53 +0000
committerUlrich Drepper <drepper@redhat.com>1997-03-27 01:59:53 +0000
commite7fd8a39abd3a9c9d2139e686b17efb5dc3bf444 (patch)
tree637853189c42709eb7fa91817173d6097765888a /sysdeps/libm-ieee754/s_log2.c
parent34b402e5a967b97fc73cc45fbef61bbeb8526f3d (diff)
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1997-03-27 02:28  Ulrich Drepper  <drepper@cygnus.com>

	* gmon/gmon.c (monstartup): Mark all messages.
	(write_call_graph): Rewrite to use larger I/O vector for writev
	call to reduce syscall overhead.
	(write_bb_counts): Simplify writev handling.

	* inet/rexec.c: Make string parameters `const'.
	* resolv/netdb.h: Add prototypes for rcmd, rexec, ruserok, and
	rresvport.

	* math/Makefile: Don't define CFLAGS-* macros to prevent inlining
	in libm-test.
	* math/libm-test.c (this_does_nothing): Remove functions.  It's
	notuseful on any platform but ix86.
	(inverse_func_pair_test): Don't use this_does_nothing.  Use
	memory reference.
	(identities1_test): Likewise.
	(identities2_test): Likewise.
	(identities3_test): Likewise.
	(basic_test): Likewise.
	Patch by Andreas Schwab.
	(BUILD_COMPLEX): New macro.  Create complex number from real and
	imaginary parts.  This works around bugs/inefficiencies in current
	gcc.
	(cexp_test): Use BUILD_COMPLEX.  Add more tests.

	* nss/nsswitch.c: Fix typo.

	* posix/glob.h: Add declaration for glob_pattern_p.
	* posix/glob.c: Rename glob_pattern_p to __glob_pattern_p and
	make glob_pattern_p a weak alias.  This function is used in other
	packages (e.g. bash).

	* signal/Makefile (routines): Add sigisempty, sigandset, and
	sigorset.
	* signal/signal.h: Add prototypes for sigisempty, sigandset, and
	sigorset.
	* signal/sigisempty.c: New file.
	* signal/sigandset.c: New file.
	* signal/sigorset.c: New file.
	* sysdeps/generic/sigset.h: Define __sigisemptyset, __sigandset,
	and __sigorset.
	* sysdeps/unix/sysv/linux/sigset.h: Likewise.

	* stdlib/strtod.c: Handle `n-char-sequence' in NaN parsing.  It
	determines the bits in the mantissa part of the NaN.
	* stdlib/strtof.c: Define SET_MANTISSA for float type.
	* wcsmbs/wcstof.c: Define SET_MANTISSA for float type.
	* stdlib/strtold.c: Define SET_MANTISSA for long double type.
	* wcsmbs/wcstold.c: Define SET_MANTISSA for long double type.

	* sysdeps/libm-ieee754/s_cexp.c: Use explicit assignment to
	complex number components.  Some more corrects for special cases.
	* sysdeps/libm-ieee754/s_cexpf.c: Likewise.
	* sysdeps/libm-ieee754/s_cexpl.c: Likewise.

	* sysdeps/sparc/elf/start.S: Remove as per request of Miguel de Icaza.

	* sysdeps/unix/sysv/linux/netinet/icmp.h: Remove since we have
	ip_icmp.h.  Reported by HJ Lu.

1997-03-25 03:50  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/m68k/Makefile (CFLAGS-rtld.c): Add -Wno-unused.

	* sysdeps/m68k/dl-machine.h (elf_machine_rela): Rewritten as for
	i386.
	(elf_machine_lookup_noexec_p, elf_machine_lookup_noplt_p,
	ELF_MACHINE_RELOC_NOPLT): Define.

1997-03-25 03:48  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* grp/grp.h: Include <stddef.h> only once.

1997-03-25 09:38  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/unix/sysv/linux/termbits.h (OXTABS): Don't define.
	* sysdeps/unix/sysv/linux/alpha/termbits.h (OXTABS): Likewise.

	* termios/sys/ttydefaults.h (TTYDEF_OFLAG): Use either OXTABS or
	TAB3, if one of them is defined.

1997-03-26 04:53  Ulrich Drepper  <drepper@cygnus.com>

	* posix/glob.c (next_brace_sub): Decrement depth counter when '}'
	is found.
	Patch by Dennis Henriksen <opus@flamingo.osrl.dk>.

1997-03-25  16:25  Thorsten Kukuk  <kukuk@vt.uni-paderborn.de>

	* sunrpc/Makefile: Comment gccwarn out.
	* sunrpc/auth_none.c: Fix prototypes and parameters for compiling
	with enabled warnings.
	* sunrpc/auth_unix.c: Likewise.
	* sunrpc/authuxprot.c: Likewise.
	* sunrpc/bindrsvprt.c: Likewise.
	* sunrpc/clnt_gen.c: Likewise.
	* sunrpc/clnt_perr.c: Likewise.
	* sunrpc/clnt_raw.c: Likewise.
	* sunrpc/clnt_simp.c: Likewise.
	* sunrpc/clnt_tcp.c: Likewise.
	* sunrpc/clnt_udp.c: Likewise.
	* sunrpc/get_myaddr.c: Likewise.
	* sunrpc/getrpcport.c: Likewise.
	* sunrpc/pm_getmaps.c: Likewise.
	* sunrpc/pm_getport.c: Likewise.
	* sunrpc/pmap_clnt.c: Likewise.
	* sunrpc/pmap_prot.c: Likewise.
	* sunrpc/pmap_prot2.c: Likewise.
	* sunrpc/pmap_rmt.c: Likewise.
	* sunrpc/rpc/auth.h: Likewise.
	* sunrpc/rpc/clnt.h: Likewise.
	* sunrpc/rpc/pmap_clnt.h: Likewise.
	* sunrpc/rpc/svc.h: Likewise.
	* sunrpc/rpc/svc_auth.h: Likewise.
	* sunrpc/rpc/types.h: Likewise.
	* sunrpc/rpc/xdr.h: Likewise.
	* sunrpc/rpc_clntout.c: Likewise.
	* sunrpc/rpc_cmsg.c: Likewise.
	* sunrpc/rpc_dtable.c: Likewise.
	* sunrpc/rpc_prot.c: Likewise.
	* sunrpc/svc.c: Likewise.
	* sunrpc/svc_auth.c: Likewise.
	* sunrpc/svc_authux.c: Likewise.
	* sunrpc/svc_raw.c: Likewise.
	* sunrpc/svc_run.c: Likewise.
	* sunrpc/svc_simple.c: Likewise.
	* sunrpc/svc_tcp.c: Likewise.
	* sunrpc/svc_udp.c: Likewise.
	* sunrpc/xdr.c: Likewise.
	* sunrpc/xdr_array.c: Likewise.
	* sunrpc/xdr_mem.c: Likewise.
	* sunrpc/xdr_rec.c: Likewise.
	* sunrpc/xdr_ref.c: Likewise.
	* sunrpc/xdr_stdio.c: Likewise.

1997-03-25 13:39  Ulrich Drepper  <drepper@cygnus.com>

	* math/libm-test.c (log2_test): Compile this function and call it.
	(exp2_test): Likewise, but check whether function really exists
	before testing.

	* math/Makefile (libm-calls): Add s_log2 and s_exp2.

1997-03-25 04:50  Ulrich Drepper  <drepper@cygnus.com>

	Implement exp2 function.
	* sysdeps/libm-i387/s_exp2.S: New file.
	* sysdeps/libm-i387/s_exp2f.S: New file.
	* sysdeps/libm-i387/s_exp2l.S: New file.

	Implement log2 function.
	* sysdeps/libm-i387/s_log2.S: New file.
	* sysdeps/libm-i387/s_log2f.S: New file.
	* sysdeps/libm-i387/s_log2l.S: New file.
	* sysdeps/libm-ieee754/s_log2.c: New file.
	* sysdeps/libm-ieee754/s_log2f.c: New file.
	* sysdeps/stub/s_log2.c: New file.  Stub version.
Diffstat (limited to 'sysdeps/libm-ieee754/s_log2.c')
-rw-r--r--sysdeps/libm-ieee754/s_log2.c129
1 files changed, 129 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_log2.c b/sysdeps/libm-ieee754/s_log2.c
new file mode 100644
index 0000000000..03a7deaa67
--- /dev/null
+++ b/sysdeps/libm-ieee754/s_log2.c
@@ -0,0 +1,129 @@
+/* Adapted for log2 by Ulrich Drepper <drepper@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.
+ * ====================================================
+ */
+
+/* __log2(x)
+ * Return the logarithm to base 2 of x
+ *
+ * Method :
+ *   1. Argument Reduction: find k and f such that
+ *			x = 2^k * (1+f),
+ *	   where  sqrt(2)/2 < 1+f < sqrt(2) .
+ *
+ *   2. Approximation of log(1+f).
+ *	Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s)
+ *		 = 2s + 2/3 s**3 + 2/5 s**5 + .....,
+ *	     	 = 2s + s*R
+ *      We use a special Reme algorithm on [0,0.1716] to generate
+ * 	a polynomial of degree 14 to approximate R The maximum error
+ *	of this polynomial approximation is bounded by 2**-58.45. In
+ *	other words,
+ *		        2      4      6      8      10      12      14
+ *	    R(z) ~ Lg1*s +Lg2*s +Lg3*s +Lg4*s +Lg5*s  +Lg6*s  +Lg7*s
+ *  	(the values of Lg1 to Lg7 are listed in the program)
+ *	and
+ *	    |      2          14          |     -58.45
+ *	    | Lg1*s +...+Lg7*s    -  R(z) | <= 2
+ *	    |                             |
+ *	Note that 2s = f - s*f = f - hfsq + s*hfsq, where hfsq = f*f/2.
+ *	In order to guarantee error in log below 1ulp, we compute log
+ *	by
+ *		log(1+f) = f - s*(f - R)	(if f is not too large)
+ *		log(1+f) = f - (hfsq - s*(hfsq+R)).	(better accuracy)
+ *
+ *	3. Finally,  log(x) = k + log(1+f).
+ *			    = k+(f-(hfsq-(s*(hfsq+R))))
+ *
+ * Special cases:
+ *	log2(x) is NaN with signal if x < 0 (including -INF) ;
+ *	log2(+INF) is +INF; log(0) is -INF with signal;
+ *	log2(NaN) is that NaN with no signal.
+ *
+ * Constants:
+ * The hexadecimal values are the intended ones for the following
+ * constants. The decimal values may be used, provided that the
+ * compiler will convert from decimal to binary accurately enough
+ * to produce the hexadecimal values shown.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const double
+#else
+static double
+#endif
+two54   =  1.80143985094819840000e+16,  /* 43500000 00000000 */
+Lg1 = 6.666666666666735130e-01,  /* 3FE55555 55555593 */
+Lg2 = 3.999999999940941908e-01,  /* 3FD99999 9997FA04 */
+Lg3 = 2.857142874366239149e-01,  /* 3FD24924 94229359 */
+Lg4 = 2.222219843214978396e-01,  /* 3FCC71C5 1D8E78AF */
+Lg5 = 1.818357216161805012e-01,  /* 3FC74664 96CB03DE */
+Lg6 = 1.531383769920937332e-01,  /* 3FC39A09 D078C69F */
+Lg7 = 1.479819860511658591e-01;  /* 3FC2F112 DF3E5244 */
+
+#ifdef __STDC__
+static const double zero   =  0.0;
+#else
+static double zero   =  0.0;
+#endif
+
+#ifdef __STDC__
+	double __log2(double x)
+#else
+	double __log2(x)
+	double x;
+#endif
+{
+	double hfsq,f,s,z,R,w,t1,t2,dk;
+	int32_t k,hx,i,j;
+	u_int32_t lx;
+
+	EXTRACT_WORDS(hx,lx,x);
+
+	k=0;
+	if (hx < 0x00100000) {			/* x < 2**-1022  */
+	    if (((hx&0x7fffffff)|lx)==0)
+		return -two54/zero;		/* log(+-0)=-inf */
+	    if (hx<0) return (x-x)/zero;	/* log(-#) = NaN */
+	    k -= 54; x *= two54; /* subnormal number, scale up x */
+	    GET_HIGH_WORD(hx,x);
+	}
+	if (hx >= 0x7ff00000) return x+x;
+	k += (hx>>20)-1023;
+	hx &= 0x000fffff;
+	i = (hx+0x95f64)&0x100000;
+	SET_HIGH_WORD(x,hx|(i^0x3ff00000));	/* normalize x or x/2 */
+	k += (i>>20);
+	dk = (double) k;
+	f = x-1.0;
+	if((0x000fffff&(2+hx))<3) {	/* |f| < 2**-20 */
+	    if(f==zero) return dk;
+	    R = f*f*(0.5-0.33333333333333333*f);
+	    return dk-(R-f);
+	}
+ 	s = f/(2.0+f);
+	z = s*s;
+	i = hx-0x6147a;
+	w = z*z;
+	j = 0x6b851-hx;
+	t1= w*(Lg2+w*(Lg4+w*Lg6));
+	t2= z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7)));
+	i |= j;
+	R = t2+t1;
+	if(i>0) {
+	    hfsq=0.5*f*f;
+	    return dk-((hfsq-(s*(hfsq+R)))-f);
+	} else {
+	    return dk-((s*(f-R))-f);
+	}
+}