PERFORCE change 55324 for review
Marcel Moolenaar
marcel at FreeBSD.org
Sat Jun 19 18:05:40 GMT 2004
http://perforce.freebsd.org/chv.cgi?CH=55324
Change 55324 by marcel at marcel_nfs on 2004/06/19 18:04:51
IFC @55323
Affected files ...
.. //depot/projects/gdb/contrib/gcc/config/i386/i386.c#2 integrate
.. //depot/projects/gdb/contrib/smbfs/lib/smb/rap.c#2 integrate
.. //depot/projects/gdb/lib/libarchive/archive_entry.c#15 integrate
.. //depot/projects/gdb/lib/libkvm/kvm_proc.c#6 integrate
.. //depot/projects/gdb/lib/msun/i387/s_ilogb.S#2 integrate
.. //depot/projects/gdb/lib/msun/man/ieee.3#3 integrate
.. //depot/projects/gdb/lib/msun/man/math.3#2 integrate
.. //depot/projects/gdb/lib/msun/src/math.h#6 integrate
.. //depot/projects/gdb/share/man/man5/rc.conf.5#13 integrate
.. //depot/projects/gdb/sys/amd64/include/pmap.h#9 integrate
.. //depot/projects/gdb/sys/arm/arm/pmap.c#2 integrate
.. //depot/projects/gdb/sys/arm/sa11x0/sa11x0.c#2 integrate
.. //depot/projects/gdb/sys/arm/sa11x0/sa11x0_ost.c#2 integrate
.. //depot/projects/gdb/sys/dev/acpica/acpi_cpu.c#10 integrate
.. //depot/projects/gdb/sys/geom/geom_dev.c#6 integrate
.. //depot/projects/gdb/sys/i386/i386/machdep.c#11 integrate
.. //depot/projects/gdb/sys/kern/kern_descrip.c#10 integrate
.. //depot/projects/gdb/sys/kern/kern_proc.c#10 integrate
.. //depot/projects/gdb/sys/kern/kern_thread.c#16 integrate
.. //depot/projects/gdb/sys/kern/sysv_shm.c#4 integrate
.. //depot/projects/gdb/sys/kern/uipc_socket.c#12 integrate
.. //depot/projects/gdb/sys/kern/uipc_socket2.c#11 integrate
.. //depot/projects/gdb/sys/kern/uipc_syscalls.c#15 integrate
.. //depot/projects/gdb/sys/kern/vfs_syscalls.c#13 integrate
.. //depot/projects/gdb/sys/net/pfil.h#2 integrate
.. //depot/projects/gdb/sys/sys/_lock.h#3 integrate
.. //depot/projects/gdb/sys/sys/_types.h#6 integrate
.. //depot/projects/gdb/sys/sys/file.h#3 integrate
.. //depot/projects/gdb/sys/sys/proc.h#18 integrate
.. //depot/projects/gdb/sys/sys/sysctl.h#7 integrate
.. //depot/projects/gdb/sys/sys/types.h#9 integrate
.. //depot/projects/gdb/sys/sys/user.h#6 integrate
.. //depot/projects/gdb/sys/vm/vm_page.c#11 integrate
.. //depot/projects/gdb/usr.sbin/newsyslog/newsyslog.c#7 integrate
Differences ...
==== //depot/projects/gdb/contrib/gcc/config/i386/i386.c#2 (text+ko) ====
@@ -20,7 +20,7 @@
Boston, MA 02111-1307, USA. */
-/* $FreeBSD: src/contrib/gcc/config/i386/i386.c,v 1.18 2003/11/07 03:17:46 kan Exp $ */
+/* $FreeBSD: src/contrib/gcc/config/i386/i386.c,v 1.19 2004/06/19 07:29:04 obrien Exp $ */
#include "config.h"
@@ -14607,15 +14607,14 @@
output_asm_insn ("mov{l}\t{%0, %1|%1, %0}", xops);
}
- xops[0] = DECL_RTL (function);
+ xops[0] = XEXP (DECL_RTL (function), 0);
if (TARGET_64BIT)
{
if (!flag_pic || (*targetm.binds_local_p) (function))
output_asm_insn ("jmp\t%P0", xops);
else
{
- tmp = XEXP (xops[0], 0);
- tmp = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, tmp), UNSPEC_GOTPCREL);
+ tmp = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, xops[0]), UNSPEC_GOTPCREL);
tmp = gen_rtx_CONST (Pmode, tmp);
tmp = gen_rtx_MEM (QImode, tmp);
xops[0] = tmp;
==== //depot/projects/gdb/contrib/smbfs/lib/smb/rap.c#2 (text+ko) ====
@@ -30,7 +30,7 @@
* SUCH DAMAGE.
*
* $Id: rap.c,v 1.8 2001/02/24 15:56:05 bp Exp $
- * $FreeBSD: src/contrib/smbfs/lib/smb/rap.c,v 1.2 2003/07/26 04:02:22 peter Exp $
+ * $FreeBSD: src/contrib/smbfs/lib/smb/rap.c,v 1.3 2004/06/19 10:09:44 le Exp $
*
* This is very simple implementation of RAP protocol.
*/
@@ -199,7 +199,7 @@
rap = malloc(sizeof(*rap));
if (rap == NULL)
- return NULL;
+ return 0;
bzero(rap, sizeof(*rap));
p = rap->r_sparam = rap->r_nparam = strdup(param);
rap->r_sdata = rap->r_ndata = strdup(data);
==== //depot/projects/gdb/lib/libarchive/archive_entry.c#15 (text+ko) ====
@@ -25,7 +25,7 @@
*/
#include "archive_platform.h"
-__FBSDID("$FreeBSD: src/lib/libarchive/archive_entry.c,v 1.14 2004/05/27 04:01:58 kientzle Exp $");
+__FBSDID("$FreeBSD: src/lib/libarchive/archive_entry.c,v 1.15 2004/06/19 04:19:27 kientzle Exp $");
#include <sys/stat.h>
#include <sys/types.h>
@@ -1366,6 +1366,8 @@
bits &= ~(flag->set | flag->clear);
}
+ if (length == 0)
+ return (NULL);
string = malloc(length);
if (string == NULL)
return (NULL);
==== //depot/projects/gdb/lib/libkvm/kvm_proc.c#6 (text+ko) ====
@@ -42,7 +42,7 @@
#endif
#include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libkvm/kvm_proc.c,v 1.75 2004/06/17 17:16:39 phk Exp $");
+__FBSDID("$FreeBSD: src/lib/libkvm/kvm_proc.c,v 1.76 2004/06/19 14:08:10 gad Exp $");
/*
* Proc traversal interface for kvm. ps and w are (probably) the exclusive
@@ -58,6 +58,7 @@
#include <sys/proc.h>
#include <sys/exec.h>
#include <sys/stat.h>
+#include <sys/sysent.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/file.h>
@@ -108,6 +109,8 @@
struct proc proc;
struct proc pproc;
struct timeval tv;
+ struct sysentvec sysent;
+ char svname[KI_EMULNAMELEN];
kp = &kinfo_proc;
kp->ki_structsize = sizeof(kinfo_proc);
@@ -156,11 +159,21 @@
switch(what & ~KERN_PROC_INC_THREAD) {
+ case KERN_PROC_GID:
+ if (kp->ki_groups[0] != (gid_t)arg)
+ continue;
+ break;
+
case KERN_PROC_PID:
if (proc.p_pid != (pid_t)arg)
continue;
break;
+ case KERN_PROC_RGID:
+ if (kp->ki_rgid != (gid_t)arg)
+ continue;
+ break;
+
case KERN_PROC_UID:
if (kp->ki_uid != (uid_t)arg)
continue;
@@ -208,11 +221,11 @@
}
kp->ki_start = pstats.p_start;
kp->ki_rusage = pstats.p_ru;
- kp->ki_childtime.tv_sec = pstats.p_cru.ru_utime.tv_sec +
- pstats.p_cru.ru_stime.tv_sec;
- kp->ki_childtime.tv_usec =
- pstats.p_cru.ru_utime.tv_usec +
- pstats.p_cru.ru_stime.tv_usec;
+ kp->ki_childstime = pstats.p_cru.ru_stime;
+ kp->ki_childutime = pstats.p_cru.ru_utime;
+ /* Some callers want child-times in a single value */
+ timeradd(&kp->ki_childstime, &kp->ki_childutime,
+ &kp->ki_childtime);
}
if (proc.p_oppid)
kp->ki_ppid = proc.p_oppid;
@@ -304,6 +317,11 @@
continue;
break;
+ case KERN_PROC_SESSION:
+ if (kp->ki_sid != (pid_t)arg)
+ continue;
+ break;
+
case KERN_PROC_TTY:
if ((proc.p_flag & P_CONTROLT) == 0 ||
kp->ki_tdev != (dev_t)arg)
@@ -314,6 +332,12 @@
strncpy(kp->ki_comm, proc.p_comm, MAXCOMLEN);
kp->ki_comm[MAXCOMLEN] = 0;
}
+ (void)kvm_read(kd, (u_long)proc.p_sysent, (char *)&sysent,
+ sizeof(sysent));
+ (void)kvm_read(kd, (u_long)sysent.sv_name, (char *)&svname,
+ sizeof(svname));
+ if (svname[0] != 0)
+ strlcpy(kp->ki_emul, svname, KI_EMULNAMELEN);
if ((proc.p_state != PRS_ZOMBIE) &&
(mtd.td_blocked != 0)) {
kp->ki_kiflag |= KI_LOCKBLOCK;
==== //depot/projects/gdb/lib/msun/i387/s_ilogb.S#2 (text+ko) ====
@@ -33,9 +33,14 @@
* J.T. Conklin (jtc at wimsey.com), Winning Strategies, Inc.
*/
+#include <machine/_limits.h>
#include <machine/asm.h>
-RCSID("$FreeBSD: src/lib/msun/i387/s_ilogb.S,v 1.8 2000/06/06 12:12:36 bde Exp $")
+RCSID("$FreeBSD: src/lib/msun/i387/s_ilogb.S,v 1.9 2004/06/19 09:30:00 stefanf Exp $")
+
+#define FP_ILOGB0 (-__INT_MAX)
+#define FP_ILOGBNAN __INT_MAX
+#define FP_ILOGBINF __INT_MAX
ENTRY(ilogb)
pushl %ebp
@@ -44,10 +49,35 @@
fldl 8(%ebp)
fxtract
- fstp %st
+ fstp %st(0)
fistpl -4(%ebp)
movl -4(%ebp),%eax
+ /* fistpl yields __INT_MIN for NaN, Inf and 0. */
+ cmpl $__INT_MIN,%eax
+ je .L2
+
+.L1:
leave
ret
+
+.L2:
+ fldl 8(%ebp)
+ fldz
+ fucompp
+ fnstsw %ax
+ sahf
+ jp .L3
+ jz .L4
+
+ movl $FP_ILOGBINF,%eax
+ jmp .L1
+
+.L3:
+ movl $FP_ILOGBNAN,%eax
+ jmp .L1
+
+.L4:
+ movl $FP_ILOGB0,%eax
+ jmp .L1
==== //depot/projects/gdb/lib/msun/man/ieee.3#3 (text+ko) ====
@@ -30,7 +30,7 @@
.\" SUCH DAMAGE.
.\"
.\" from: @(#)ieee.3 6.4 (Berkeley) 5/6/91
-.\" $FreeBSD: src/lib/msun/man/ieee.3,v 1.13 2004/05/07 18:56:31 stefanf Exp $
+.\" $FreeBSD: src/lib/msun/man/ieee.3,v 1.14 2004/06/19 09:33:29 stefanf Exp $
.\"
.Dd February 25, 1994
.Dt IEEE 3
@@ -116,11 +116,14 @@
in integer format.
.Fn ilogb \*(Pm\*(If
returns
-.Dv INT_MAX
+.Dv INT_MAX ,
+.Fn ilogb \*(Pm\*(Na
+returns
+.Dv FP_ILOGBNAN
and
.Fn ilogb 0
returns
-.Dv INT_MIN .
+.Dv FP_ILOGB0 .
.Pp
.Fn nextafter
and
==== //depot/projects/gdb/lib/msun/man/math.3#2 (text+ko) ====
@@ -30,297 +30,141 @@
.\" SUCH DAMAGE.
.\"
.\" from: @(#)math.3 6.10 (Berkeley) 5/6/91
-.\" $FreeBSD: src/lib/msun/man/math.3,v 1.10 2001/07/15 07:53:37 dd Exp $
+.\" $FreeBSD: src/lib/msun/man/math.3,v 1.11 2004/06/19 03:25:28 das Exp $
.\"
-.TH MATH 3M "May 6, 1991"
-.UC 4
+.Dd June 11, 2004
+.Dt MATH 3
+.Os
.ds up \fIulp\fR
-.ds nn \fINaN\fR
.de If
.if n \\
\\$1Infinity\\$2
.if t \\
\\$1\\(if\\$2
..
-.SH NAME
+.Sh NAME
math \- introduction to mathematical library functions
-.SH DESCRIPTION
+.Sh DESCRIPTION
These functions constitute the C math library,
.I libm.
The link editor searches this library under the \*(lq\-lm\*(rq option.
Declarations for these functions may be obtained from the include file
-.RI < math.h >.
-.\" The Fortran math library is described in ``man 3f intro''.
-.SH "LIST OF FUNCTIONS"
-Each of the following double functions has a float counterpart with the
-name ending in f, as an example the float counterpart of double acos(double
-x) is float acosf(float x).
+.In math.h .
+.Sh "LIST OF FUNCTIONS"
+Each of the following
+.Vt double
+functions has a
+.Vt float
+counterpart with an
+.Ql f
+appended to the name and a
+.Vt long double
+counterpart with an
+.Ql l
+appended.
+As an example, the
+.Vt float
+and
+.Vt long double
+counterparts of
+.Ft double
+.Fn acos "double x"
+are
+.Ft float
+.Fn acosf "float x"
+and
+.Ft long double
+.Fn acosl "long double x" ,
+respectively.
.sp 2
.nf
-.ta \w'copysign'u+2n +\w'infnan.3m'u+10n +\w'inverse trigonometric func'u
-\fIName\fP \fIAppears on Page\fP \fIDescription\fP \fIError Bound (ULPs)\fP
-.ta \w'copysign'u+4n +\w'infnan.3m'u+4n +\w'inverse trigonometric function'u+6nC
+.ta \w'nexttoward'u+10n +\w'remainder with partial quot'u
+\fIName\fP \fIDescription\fP \fIError Bound (ULPs)\fP
+.ta \w'nexttoward'u+4n +\w'remainder with partial quotient'u+6nC
.sp 5p
-acos sin.3m inverse trigonometric function 3
-acosh asinh.3m inverse hyperbolic function 3
-asin sin.3m inverse trigonometric function 3
-asinh asinh.3m inverse hyperbolic function 3
-atan sin.3m inverse trigonometric function 1
-atanh asinh.3m inverse hyperbolic function 3
-atan2 sin.3m inverse trigonometric function 2
-cabs hypot.3m complex absolute value 1
-cbrt sqrt.3m cube root 1
-ceil floor.3m integer no less than 0
-copysign ieee.3m copy sign bit 0
-cos sin.3m trigonometric function 1
-cosh sinh.3m hyperbolic function 3
-erf erf.3m error function ???
-erfc erf.3m complementary error function ???
-exp exp.3m exponential 1
-expm1 exp.3m exp(x)\-1 1
-fabs floor.3m absolute value 0
-floor floor.3m integer no greater than 0
-hypot hypot.3m Euclidean distance 1
-ilogb ieee.3m exponent extraction 0
-j0 j0.3m bessel function ???
-j1 j0.3m bessel function ???
-jn j0.3m bessel function ???
-lgamma lgamma.3m log gamma function; (formerly gamma.3m)
-log exp.3m natural logarithm 1
-log10 exp.3m logarithm to base 10 3
-log1p exp.3m log(1+x) 1
-pow exp.3m exponential x**y 60\-500
-remainder ieee.3m remainder 0
-rint floor.3m round to nearest integer 0
-scalbn ieee.3m exponent adjustment 0
-sin sin.3m trigonometric function 1
-sinh sinh.3m hyperbolic function 3
-sqrt sqrt.3m square root 1
-tan sin.3m trigonometric function 3
-tanh sinh.3m hyperbolic function 3
-y0 j0.3m bessel function ???
-y1 j0.3m bessel function ???
-yn j0.3m bessel function ???
+.\" XXX Many of these error bounds are wrong for the current implementation!
+acos inverse trigonometric function 3
+acosh inverse hyperbolic function 3
+asin inverse trigonometric function 3
+asinh inverse hyperbolic function 3
+atan inverse trigonometric function 1
+atanh inverse hyperbolic function 3
+atan2 inverse trigonometric function 2
+cbrt cube root 1
+ceil integer no less than 0
+copysign copy sign bit 0
+cos trigonometric function 1
+cosh hyperbolic function 3
+erf error function ???
+erfc complementary error function ???
+exp exponential base e 1
+.\" exp2 exponential base 2 ???
+expm1 exp(x)\-1 1
+fabs absolute value 0
+.\" fdim positive difference ???
+floor integer no greater than 0
+.\" fma multiply-add ???
+.\" fmax maximum function 0
+.\" fmin minimum function 0
+fmod remainder function ???
+frexp extract mantissa and exponent 0
+hypot Euclidean distance 1
+ilogb exponent extraction 0
+j0 bessel function ???
+j1 bessel function ???
+jn bessel function ???
+ldexp multiply by power of 2 0
+lgamma log gamma function ???
+.\" llrint round to integer 0
+.\" llround round to nearest integer 0
+log natural logarithm 1
+log10 logarithm to base 10 3
+log1p log(1+x) 1
+.\" log2 base 2 logarithm 0
+logb exponent extraction 0
+.\" lrint round to integer 0
+.\" lround round to nearest integer 0
+modf extract fractional part ???
+.\" nan return quiet \*(Na) 0
+.\" nearbyint round to integer 0
+.\" nextafter next representable value 0
+.\" nexttoward next representable value 0
+pow exponential x**y 60\-500
+remainder remainder 0
+.\" remquo remainder with partial quotient ???
+rint round to nearest integer 0
+round round to nearest integer 0
+.\" scalbln exponent adjustment 0
+scalbn exponent adjustment 0
+sin trigonometric function 1
+sinh hyperbolic function 3
+sqrt square root 1
+tan trigonometric function 3
+tanh hyperbolic function 3
+tgamma gamma function ???
+.\" trunc round towards zero 0
+y0 bessel function ???
+y1 bessel function ???
+yn bessel function ???
.ta
.fi
-.SH NOTES
-In 4.3 BSD, distributed from the University of California
-in late 1985, most of the foregoing functions come in two
-versions, one for the double\-precision "D" format in the
-DEC VAX\-11 family of computers, another for double\-precision
-arithmetic conforming to the IEEE Standard 754 for Binary
-Floating\-Point Arithmetic. The two versions behave very
-similarly, as should be expected from programs more accurate
-and robust than was the norm when UNIX was born. For
-instance, the programs are accurate to within the numbers
+.Sh NOTES
+Virtually all modern floating-point units attempt to support
+IEEE Standard 754 for Binary Floating-Point Arithmetic.
+This standard does not cover particular routines in the math library
+except for the few documented in
+.Xr ieee 3 ;
+it primarily defines representations of numbers and abstract
+properties of arithmetic operations relating to precision, rounding,
+and exceptional cases, as described below.
+The programs are accurate to within the numbers
of \*(ups tabulated above; an \*(up is one \fIU\fRnit in the \fIL\fRast
-\fIP\fRlace. And the programs have been cured of anomalies that
-afflicted the older math library \fIlibm\fR in which incidents like
-the following had been reported:
-.RS
-sqrt(\-1.0) = 0.0 and log(\-1.0) = \-1.7e38.
-.br
-cos(1.0e\-11) > cos(0.0) > 1.0.
-.br
-pow(x,1.0)
-.if n \
-!=
-.if t \
-\(!=
-x when x = 2.0, 3.0, 4.0, ..., 9.0.
-.br
-pow(\-1.0,1.0e10) trapped on Integer Overflow.
-.br
-sqrt(1.0e30) and sqrt(1.0e\-30) were very slow.
-.RE
-However the two versions do differ in ways that have to be
-explained, to which end the following notes are provided.
-.PP
-\fBDEC VAX\-11 D_floating\-point:\fR
-.PP
-This is the format for which the original math library \fIlibm\fR
-was developed, and to which this manual is still principally
-dedicated. It is \fIthe\fR double\-precision format for the PDP\-11
-and the earlier VAX\-11 machines; VAX\-11s after 1983 were
-provided with an optional "G" format closer to the IEEE
-double\-precision format. The earlier DEC MicroVAXs have no
-D format, only G double\-precision.
-(Why? Why not?)
-.PP
-Properties of D_floating\-point:
-.RS
-Wordsize: 64 bits, 8 bytes. Radix: Binary.
-.br
-Precision: 56
-.if n \
-sig.
-.if t \
-significant
-bits, roughly like 17
-.if n \
-sig.
-.if t \
-significant
-decimals.
-.RS
-If x and x' are consecutive positive D_floating\-point
-numbers (they differ by 1 \*(up), then
-.br
-1.3e\-17 < 0.5**56 < (x'\-x)/x \(<= 0.5**55 < 2.8e\-17.
-.RE
-.nf
-.ta \w'Range:'u+1n +\w'Underflow threshold'u+1n +\w'= 2.0**127'u+1n
-Range: Overflow threshold = 2.0**127 = 1.7e38.
- Underflow threshold = 0.5**128 = 2.9e\-39.
- NOTE: THIS RANGE IS COMPARATIVELY NARROW.
-.ta
-.fi
-.RS
-Overflow customarily stops computation.
-.br
-Underflow is customarily flushed quietly to zero.
-.br
-CAUTION:
-.RS
-It is possible to have x
-.if n \
-!=
-.if t \
-\(!=
-y and yet
-x\-y = 0 because of underflow. Similarly
-x > y > 0 cannot prevent either x\(**y = 0
-or y/x = 0 from happening without warning.
-.RE
-.RE
-Zero is represented ambiguously.
-.RS
-Although 2**55 different representations of zero are accepted by
-the hardware, only the obvious representation is ever produced.
-There is no \-0 on a VAX.
-.RE
-.If
-is not part of the VAX architecture.
-.br
-Reserved operands:
-.RS
-of the 2**55 that the hardware
-recognizes, only one of them is ever produced.
-Any floating\-point operation upon a reserved
-operand, even a MOVF or MOVD, customarily stops
-computation, so they are not much used.
-.RE
-Exceptions:
-.RS
-Divisions by zero and operations that
-overflow are invalid operations that customarily
-stop computation or, in earlier machines, produce
-reserved operands that will stop computation.
-.RE
-Rounding:
-.RS
-Every rational operation (+, \-, \(**, /) on a
-VAX (but not necessarily on a PDP\-11), if not an
-over/underflow nor division by zero, is rounded to
-within half an \*(up, and when the rounding error is
-exactly half an \*(up then rounding is away from 0.
-.RE
-.RE
-.PP
-Except for its narrow range, D_floating\-point is one of the
-better computer arithmetics designed in the 1960's.
-Its properties are reflected fairly faithfully in the elementary
-functions for a VAX distributed in 4.3 BSD.
-They over/underflow only if their results have to lie out of range
-or very nearly so, and then they behave much as any rational
-arithmetic operation that over/underflowed would behave.
-Similarly, expressions like log(0) and atanh(1) behave
-like 1/0; and sqrt(\-3) and acos(3) behave like 0/0;
-they all produce reserved operands and/or stop computation!
-The situation is described in more detail in manual pages.
-.RS
-.ll -0.5i
-\fIThis response seems excessively punitive, so it is destined
-to be replaced at some time in the foreseeable future by a
-more flexible but still uniform scheme being developed to
-handle all floating\-point arithmetic exceptions neatly.
-.\" See infnan(3M) for the present state of affairs.\fR
-.ll +0.5i
-.RE
-.PP
-How do the functions in 4.3 BSD's new \fIlibm\fR for UNIX
-compare with their counterparts in DEC's VAX/VMS library?
-Some of the VMS functions are a little faster, some are
-a little more accurate, some are more puritanical about
-exceptions (like pow(0.0,0.0) and atan2(0.0,0.0)),
-and most occupy much more memory than their counterparts in
-\fIlibm\fR.
-The VMS codes interpolate in large table to achieve
-speed and accuracy; the \fIlibm\fR codes use tricky formulas
-compact enough that all of them may some day fit into a ROM.
-.PP
-More important, DEC regards the VMS codes as proprietary
-and guards them zealously against unauthorized use. But the
-\fIlibm\fR codes in 4.3 BSD are intended for the public domain;
-they may be copied freely provided their provenance is always
-acknowledged, and provided users assist the authors in their
-researches by reporting experience with the codes.
-Therefore no user of UNIX on a machine whose arithmetic resembles
-VAX D_floating\-point need use anything worse than the new \fIlibm\fR.
-.PP
+\fIP\fRlace.
+.Pp
\fBIEEE STANDARD 754 Floating\-Point Arithmetic:\fR
-.PP
-This standard is on its way to becoming more widely adopted
-than any other design for computer arithmetic.
-VLSI chips that conform to some version of that standard have been
-produced by a host of manufacturers, among them ...
-.nf
-.ta 0.5i +\w'Intel i8070, i80287'u+6n
- Intel i8087, i80287 National Semiconductor 32081
- Motorola 68881 Weitek WTL-1032, ... , -1165
- Zilog Z8070 Western Electric (AT&T) WE32106.
-.ta
-.fi
-Other implementations range from software, done thoroughly
-in the Apple Macintosh, through VLSI in the Hewlett\-Packard
-9000 series, to the ELXSI 6400 running ECL at 3 Megaflops.
-Several other companies have adopted the formats
-of IEEE 754 without, alas, adhering to the standard's way
-of handling rounding and exceptions like over/underflow.
-The DEC VAX G_floating\-point format is very similar to the IEEE
-754 Double format, so similar that the C programs for the
-IEEE versions of most of the elementary functions listed
-above could easily be converted to run on a MicroVAX, though
-nobody has volunteered to do that yet.
-.PP
-The codes in 4.3 BSD's \fIlibm\fR for machines that conform to
-IEEE 754 are intended primarily for the National Semi. 32081
-and WTL 1164/65. To use these codes with the Intel or Zilog
-chips, or with the Apple Macintosh or ELXSI 6400, is to
-forego the use of better codes provided (perhaps freely) by
-those companies and designed by some of the authors of the
-codes above.
-Except for \fIatan\fR, \fIcabs\fR, \fIcbrt\fR, \fIerf\fR,
-\fIerfc\fR, \fIhypot\fR, \fIj0\-jn\fR, \fIlgamma\fR, \fIpow\fR
-and \fIy0\-yn\fR,
-the Motorola 68881 has all the functions in \fIlibm\fR on chip,
-and faster and more accurate;
-it, Apple, the i8087, Z8070 and WE32106 all use 64
-.if n \
-sig.
-.if t \
-significant
-bits.
-The main virtue of 4.3 BSD's
-\fIlibm\fR codes is that they are intended for the public domain;
-they may be copied freely provided their provenance is always
-acknowledged, and provided users assist the authors in their
-researches by reporting experience with the codes.
-Therefore no user of UNIX on a machine that conforms to
-IEEE 754 need use anything worse than the new \fIlibm\fR.
-.PP
+.Pp
Properties of IEEE 754 Double\-Precision:
-.RS
+.Bd -filled -offset indent
Wordsize: 64 bits, 8 bytes. Radix: Binary.
.br
Precision: 53
@@ -334,27 +178,27 @@
.if t \
significant
decimals.
-.RS
+.Bd -filled -offset indent -compact
If x and x' are consecutive positive Double\-Precision
numbers (they differ by 1 \*(up), then
.br
1.1e\-16 < 0.5**53 < (x'\-x)/x \(<= 0.5**52 < 2.3e\-16.
-.RE
+.Ed
.nf
.ta \w'Range:'u+1n +\w'Underflow threshold'u+1n +\w'= 2.0**1024'u+1n
Range: Overflow threshold = 2.0**1024 = 1.8e308
Underflow threshold = 0.5**1022 = 2.2e\-308
.ta
.fi
-.RS
+.Bd -filled -offset indent -compact
Overflow goes by default to a signed
.If "" .
.br
Underflow is \fIGradual,\fR rounding to the nearest
integer multiple of 0.5**1074 = 4.9e\-324.
-.RE
+.Ed
Zero is represented ambiguously as +0 or \-0.
-.RS
+.Bd -filled -offset indent -compact
Its sign transforms correctly through multiplication or
division, and is preserved by addition of zeros
with like signs; but x\-x yields +0 for every
@@ -371,10 +215,10 @@
\(!=
\-1/(y\-x) =
.If \- .
-.RE
+.Ed
.If
is signed.
-.RS
+.Bd -filled -offset indent -compact
it persists when added to itself
or to any finite number. Its sign transforms
correctly through multiplication and division, and
@@ -387,16 +231,16 @@
.if t \
\(if\-\(if, \(if\(**0 and \(if/\(if
are, like 0/0 and sqrt(\-3),
-invalid operations that produce \*(nn. ...
-.RE
+invalid operations that produce \*(Na. ...
+.Ed
Reserved operands:
-.RS
+.Bd -filled -offset indent -compact
there are 2**53\-2 of them, all
-called \*(nn (\fIN\fRot \fIa N\fRumber).
-Some, called Signaling \*(nns, trap any floating\-point operation
+called \*(Na (\fIN\fRot \fIa N\fRumber).
+Some, called Signaling \*(Nas, trap any floating\-point operation
performed upon them; they are used to mark missing
or uninitialized values, or nonexistent elements
-of arrays. The rest are Quiet \*(nns; they are
+of arrays. The rest are Quiet \*(Nas; they are
the default results of Invalid Operations, and
propagate through subsequent arithmetic operations.
If x
@@ -404,18 +248,18 @@
!=
.if t \
\(!=
-x then x is \*(nn; every other predicate
-(x > y, x = y, x < y, ...) is FALSE if \*(nn is involved.
+x then x is \*(Na; every other predicate
+(x > y, x = y, x < y, ...) is FALSE if \*(Na is involved.
.br
-NOTE: Trichotomy is violated by \*(nn.
-.RS
+NOTE: Trichotomy is violated by \*(Na.
+.Bd -filled -offset indent -compact
Besides being FALSE, predicates that entail ordered
comparison, rather than mere (in)equality,
-signal Invalid Operation when \*(nn is involved.
-.RE
-.RE
+signal Invalid Operation when \*(Na is involved.
+.Ed
+.Ed
Rounding:
-.RS
+.Bd -filled -offset indent -compact
Every algebraic operation (+, \-, \(**, /,
.if n \
sqrt)
@@ -440,19 +284,19 @@
same kinds of rounding are specified for
Binary\-Decimal Conversions, at least for magnitudes
between roughly 1.0e\-10 and 1.0e37.
-.RE
+.Ed
Exceptions:
-.RS
+.Bd -filled -offset indent -compact
IEEE 754 recognizes five kinds of floating\-point exceptions,
listed below in declining order of probable importance.
-.RS
+.Bd -filled -offset indent -compact
.nf
.ta \w'Invalid Operation'u+6n +\w'Gradual Underflow'u+2n
Exception Default Result
.tc \(ru
.tc
-Invalid Operation \*(nn, or FALSE
+Invalid Operation \*(Na, or FALSE
.if n \{\
Overflow \(+-Infinity
Divide by Zero \(+-Infinity \}
@@ -463,7 +307,7 @@
Inexact Rounded value
.ta
.fi
-.RE
+.Ed
NOTE: An Exception is not an Error unless handled
badly. What makes a class of exceptions exceptional
is that no single default response can be satisfactory
@@ -471,8 +315,8 @@
response will serve most instances satisfactorily,
the unsatisfactory instances cannot justify aborting
computation every time the exception occurs.
-.RE
-.PP
+.Ed
+.Pp
For each kind of floating\-point exception, IEEE 754
provides a Flag that is raised each time its exception
is signaled, and stays raised until the program resets
@@ -480,13 +324,14 @@
Thus, IEEE 754 provides three ways by which programs
may cope with exceptions for which the default result
might be unsatisfactory:
-.IP 1) \w'\0\0\0\0'u
+.Bl -enum
+.It
Test for a condition that might cause an exception
later, and branch to avoid the exception.
-.IP 2) \w'\0\0\0\0'u
+.It
Test a flag to see whether an exception has occurred
since the program last reset its flag.
-.IP 3) \w'\0\0\0\0'u
+.It
Test a result to see whether it is a value that only
an exception could have produced.
.RS
@@ -513,30 +358,34 @@
because they would have been rounded off anyway.
So gradual underflows are usually \fIprovably\fR ignorable.
The same cannot be said of underflows flushed to 0.
-.RE
-.PP
+.RE
+.El
+.Pp
At the option of an implementor conforming to IEEE 754,
other ways to cope with exceptions may be provided:
-.IP 4) \w'\0\0\0\0'u
+.Bl -hang -width 3n
+.It 4.
ABORT. This mechanism classifies an exception in
advance as an incident to be handled by means
traditionally associated with error\-handling
statements like "ON ERROR GO TO ...". Different
languages offer different forms of this statement,
but most share the following characteristics:
-.IP \(em \w'\0\0\0\0'u
+.Bl -dash
+.It
No means is provided to substitute a value for
the offending operation's result and resume
computation from what may be the middle of an
expression. An exceptional result is abandoned.
-.IP \(em \w'\0\0\0\0'u
+.It
In a subprogram that lacks an error\-handling
statement, an exception causes the subprogram to
abort within whatever program called it, and so
on back up the chain of calling subprograms until
an error\-handling statement is encountered or the
whole task is aborted and memory is dumped.
-.IP 5) \w'\0\0\0\0'u
+.El
+.It 5.
STOP. This mechanism, requiring an interactive
debugging environment, is more for the programmer
than the program. It classifies an exception in
@@ -548,98 +397,91 @@
unexceptionable, so the programmer ought ideally
to be able to resume execution after each one as if
execution had not been stopped.
-.IP 6) \w'\0\0\0\0'u
+.It 6.
\&... Other ways lie beyond the scope of this document.
-.RE
-.PP
-The crucial problem for exception handling is the problem of
-Scope, and the problem's solution is understood, but not
-enough manpower was available to implement it fully in time
-to be distributed in 4.3 BSD's \fIlibm\fR. Ideally, each
+.El
+.Ed
+.Pp
+Ideally, each
elementary function should act as if it were indivisible, or
atomic, in the sense that ...
-.IP i) \w'iii)'u+2n
+.Bl -tag -width "iii)"
+.It i)
No exception should be signaled that is not deserved by
the data supplied to that function.
-.IP ii) \w'iii)'u+2n
+.It ii)
Any exception signaled should be identified with that
function rather than with one of its subroutines.
-.IP iii) \w'iii)'u+2n
+.It iii)
The internal behavior of an atomic function should not
be disrupted when a calling program changes from
one to another of the five or so ways of handling
exceptions listed above, although the definition
of the function may be correlated intentionally
with exception handling.
-.PP
-Ideally, every programmer should be able \fIconveniently\fR to
-turn a debugged subprogram into one that appears atomic to
-its users. But simulating all three characteristics of an
-atomic function is still a tedious affair, entailing hosts
-of tests and saves\-restores; work is under way to ameliorate
-the inconvenience.
-.PP
-Meanwhile, the functions in \fIlibm\fR are only approximately
-atomic. They signal no inappropriate exception except
-possibly ...
-.RS
+.El
+.Pp
+The functions in \fIlibm\fR are only approximately atomic.
+They signal no inappropriate exception except possibly ...
+.Bd -filled -offset indent -compact
Over/Underflow
-.RS
+.Bd -filled -offset indent -compact
when a result, if properly computed, might have lain barely within range, and
-.RE
+.Ed
Inexact in \fIcabs\fR, \fIcbrt\fR, \fIhypot\fR, \fIlog10\fR and \fIpow\fR
-.RS
+.Bd -filled -offset indent -compact
when it happens to be exact, thanks to fortuitous cancellation of errors.
-.RE
-.RE
+.Ed
+.Ed
Otherwise, ...
-.RS
+.Bd -filled -offset indent -compact
Invalid Operation is signaled only when
-.RS
-any result but \*(nn would probably be misleading.
-.RE
+.Bd -filled -offset indent -compact
+any result but \*(Na would probably be misleading.
+.Ed
Overflow is signaled only when
-.RS
+.Bd -filled -offset indent -compact
the exact result would be finite but beyond the overflow threshold.
-.RE
+.Ed
Divide\-by\-Zero is signaled only when
-.RS
+.Bd -filled -offset indent -compact
a function takes exactly infinite values at finite operands.
-.RE
+.Ed
Underflow is signaled only when
-.RS
+.Bd -filled -offset indent -compact
the exact result would be nonzero but tinier than the underflow threshold.
-.RE
>>> TRUNCATED FOR MAIL (1000 lines) <<<
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