commit broke the 2**24 cases where |x| > DBL_MAX/2. There are exponent
range problems not just for denormals (underflow) but for large values
(overflow). Doubles have more than enough exponent range to avoid the
problems, but I forgot to convert enough terms to double, so there was
an x+x term which was sometimes evaluated in float precision.
Unfortunately, this is a pessimization with some combinations of systems
and compilers (it makes no difference on Athlon XP's, but on Athlon64's
it gives a 5% pessimization with gcc-3.4 but not with gcc-3.3).
Exlain the problem better in comments.
algorithm for the second step significantly to also get a perfectly
rounded result in round-to-nearest mode. The resulting optimization
is about 25% on Athlon64's and 30% on Athlon XP's (about 25 cycles
out of 100 on the former).
Using extra precision, we don't need to do anything special to avoid
large rounding errors in the third step (Newton's method), so we can
regroup terms to avoid a division, increase clarity, and increase
opportunities for parallelism. Rearrangement for parallelism loses
the increase in clarity. We end up with the same number of operations
but with a division reduced to a multiplication.
Using specifically double precision, there is enough extra precision
for the third step to give enough precision for perfect rounding to
float precision provided the previous steps are accurate to 16 bits.
(They were accurate to 12 bits, which was almost minimal for imperfect
rounding in the old version but would be more than enough for imperfect
rounding in this version (9 bits would be enough now).) I couldn't
find any significant time optimizations from optimizing the previous
steps, so I decided to optimize for accuracy instead. The second step
needed a division although a previous commit optimized it to use a
polynomial approximation for its main detail, and this division dominated
the time for the second step. Use the same Newton's method for the
second step as for the third step since this is insignificantly slower
than the division plus the polynomial (now that Newton's method only
needs 1 division), significantly more accurate, and simpler. Single
precision would be precise enough for the second step, but doesn't
have enough exponent range to handle denormals without the special
grouping of terms (as in previous versions) that requires another
division, so we use double precision for both the second and third
steps.
mode. This allows one to use kgdb on /dev/mem and be able to patch memory
on a live system. This is identical to what -wcore used to do in previous
gdb versions for FreeBSD.
Requested by: wpaul
ifm_status and ifm_active. IFM_10_T gets set in the ifm_active field,
not in the ifm_status field, as far as I can tell.
Note: this was to enable a workaround that's rarely enabled. I don't know
how to corrupt my eeprom to test it, and would rather not know...
part of the structure was a hack to maintain binary compatibility with
Sun binaries, and my understanding is that it's not needed generally
on sparc systems running other operating systems. Therefore, hide this
code behind the same set of tests as in lib/bind/include/netdb.h.
This file is being imported on the vendor branch because a similar change
(or change with similar effect) will be in the next version of BIND 9.
This change will not affect other platforms in any way.
- Remove a conditional in the AMD cache detection, it's always false. [2]
- Don't try to detect a cache if only compiled for i386.
Analyzed by: Antoine Brodin <antoine.brodin@laposte.net> [1]
Submitted by: Antoine Brodin <antoine.brodin@laposte.net> [2]
that a file's atime and mtime are only set to correct fractional
second values (0-999999000ns with the current interface).
Prior to this change users could create files with values outside
that range. Moreover, on 32-bit machines tv_usec offsets larger than
4.3s would result in an unnormalized AND wrong timestamp value,
due to overflow.
MFC after: 1 week
success instead of EOPNOTSUPP when being loaded. Secondly, if there are no
ibcs2 processes running when a MOD_UNLOAD request is made, break out to
return success instead of falling through into the default case which
returns EOPNOTSUPP. With these fixes, I can now kldload and subsequently
kldunload the ibcs2 module.
PR: kern/82026 (and several duplicates)
Reported by: lots of folks
MFC after: 1 week
signal is received during the msleep, the msleep is retried
indefinitely as it just keeps returning ERESTART because of
the pending signal.
Instead, just don't PCATCH - the signal can wait.
Sponsored by: Sophos/ActiveState
function in years.
- Change the 'ident' paramters to 'wchan' to match <sys/systm.h>.
- Use 'otherwise' in place of 'else' in one place so that this reads like
English rather than C.
- Document the new msleep_spin() function.
- Add history notes for msleep() and msleep_spin().
functions in the child after a fork() from a threaded process,
use __sys_setprocmask() rather than setprocmask() to keep our
signal handling sane. Without this fix, signals are essentially
ignored in said child and things such as protection violations
result in an endless busy loop.
Reviewed by: deischen
$ su
% kill -STOP $$
where su is executing (t)csh. csh's job handling is a little more
special than that of (a)sh, bash and even zsh and blows up a little
more spectacularly. This modification restores the original mucking
about with the tty pgrp, but is careful to only do it when su (or
su's child) is the foreground process.
While I'm here, fix a STDERR_FILENO spelling as suggested by bde.
