function approximation for the second step. The polynomial has degree
2 for cbrtf() and 4 for cbrt(). These degrees are minimal for the final
accuracy to be essentially the same as before (slightly smaller).
Adjust the rounding between steps 2 and 3 to match. Unfortunately,
for cbrt(), this breaks the claimed accuracy slightly although incorrect
rounding doesn't. Claim less accuracy since its not worth pessimizing
the polynomial or relying on exhaustive testing to get insignificantly
more accuracy.
This saves about 30 cycles on Athlons (mainly by avoiding 2 divisions)
so it gives an overall optimization in the 10-25% range (a larger
percentage for float precision, especially in 32-bit mode, since other
overheads are more dominant for double precision, surprisingly more
in 32-bit mode).
1. The ELF-64 typedefs are now standardized, so that the libelf port
(devel/libelf) does not need to compensate for not having the
Elf64_Xword and Elf64_Sxword types.
2. ELF Symbol versioning support has been added. This also affects
the libelf port (though configure should detect this correctly).
- in preparing for the third approximation, actually make t larger in
magnitude than cbrt(x). After chopping, t must be incremented by 2
ulps to make it larger, not 1 ulp since chopping can reduce it by
almost 1 ulp and it might already be up to half a different-sized-ulp
smaller than cbrt(x). I have not found any cases where this is
essential, but the think-time error bound depends on it. The relative
smallness of the different-sized-ulp limited the bug. If there are
cases where this is essential, then the final error bound would be
5/6+epsilon instead of of 4/6+epsilon ulps (still < 1).
- in preparing for the third approximation, round more carefully (but
still sloppily to avoid branches) so that the claimed error bound of
0.667 ulps is satisfied in all cases tested for cbrt() and remains
satisfied in all cases for cbrtf(). There isn't enough spare precision
for very sloppy rounding to work:
- in cbrt(), even with the inadequate increment, the actual error was
0.6685 in some cases, and correcting the increment increased this
a little. The fix uses sloppy rounding to 25 bits instead of very
sloppy rounding to 21 bits, and starts using uint64_t instead of 2
words for bit manipulation so that rounding more bits is not much
costly.
- in cbrtf(), the 0.667 bound was already satisfied even with the
inadequate increment, but change the code to almost match cbrt()
anyway. There is not enough spare precision in the Newton
approximation to double the inadequate increment without exceeding
the 0.667 bound, and no spare precision to avoid this problem as
in cbrt(). The fix is to round using an increment of 2 smaller-ulps
before chopping so that an increment of 1 ulp is enough. In cbrt(),
we essentially do the same, but move the chop point so that the
increment of 1 is not needed.
Fixed comments to match code:
- in cbrt(), the second approximation is good to 25 bits, not quite 26 bits.
- in cbrt(), don't claim that the second approximation may be implemented
in single precision. Single precision cannot handle the full exponent
range without minor but pessimal changes to renormalize, and although
single precision is enough, 25 bit precision is now claimed and used.
Added comments about some of the magic for the error bound 4/6+epsilon.
I still don't understand why it is 4/6+ and not 6/6+ ulps.
Indent comments at the right of code more consistently.
we can cache its value in the softc. Eliminates one PCI register
write per call to bge_start().
A 1.8% speedup for UDP_RR test on my old box.
Obtained from: NetBSD(jonathan) via delphij
to be compatible with symbol versioning support as implemented by
GNU libc and documented by http://people.redhat.com/~drepper/symbol-versioning
and LSB 3.0.
Implement dlvsym() function to allow lookups for a specific version of
a given symbol.
case if memory allocation failed.
- Remove fourth argument from VLAN_INPUT_TAG(), that was used
incorrectly in almost all drivers. Indicate failure with
mbuf value of NULL.
In collaboration with: yongari, ru, sam
means:
o Remove Elf64_Quarter,
o Redefine Elf64_Half to be 16-bit,
o Redefine Elf64_Word to be 32-bit,
o Add Elf64_Xword and Elf64_Sxword for 64-bit entities,
o Use Elf_Size in MI code to abstract the difference between
Elf32_Word and Elf64_Word.
o Add Elf_Ssize as the signed counterpart of Elf_Size.
MFC after: 2 weeks
o Remove the unused and non-standard SHT_NUM, PT_COUNT and DT_COUNT.
o Add the STV_DEFAULT, STV_INTERNAL, STV_HIDDEN and STV_PROTECTED
symbol visibility constants.
o Add the ELF32_ST_VISIBILITY and ELF64_ST_VISIBILITY macros to
get the symbol visibility from the st_other field.
o Add the ELFOSABI_AIX, ELFOSABI_OPENVMS and ELFOSABI_NSK constants.
o Add the ET_LOOS, ET_HIOS, ET_LOPROC and ET_HIPROC constants.
o Further flesh out the list of machine types. Note that EM_ALPHA
remains non-standard. The standard value for EM_ALPHA is given
by EM_ALPHA_STD (which is a non-standard name :-)
o Add the SHN_LOOS, SHN_HIOS and SHN_XINDEX constants.
o Add the SHT_INIT_ARRAY, SHT_FINI_ARRAY, SHT_PREINIT_ARRAY, SHT_GROUP
and SHT_SYMTAB_SHNDX constants.
o Add the SHF_MERGE, SHF_STRINGS, SHF_INFO_LINK, SHF_LINK_ORDER,
SHF_OS_NONCONFORMING, SHF_GROUP and SHF_MASKOS constants.
o Add the PF_MASKOS and PF_MASKPROC constants.
o Add the STB_LOOS andf STB_HIOS constants.
o Add the STT_COMMON, STT_LOOS and STT_HIOS constants.
MFC after: 1 week
32-bit entity. Also, don't cast the resulting symbol type value to
a datatype smaller than the st_info field type as a quick way to
mask off the upper bits as it may cause inconsistent behaviour when
the macro is used (without explicit casting) on varargs functions.
MFC after: 1 week
span ports when they disappear. The span port does not have a pointer to the
softc so revert r1.31 and bring back the softc linked-list.
MFC after: 2 weeks
and KTR_IO as they were never used. Remove KTR_CLK since it was only
used for hardclock firing and use KTR_INTR there instead. Remove
KTR_CRITICAL since it was only used for crit enter/exit and use
KTR_CONTENTION instead.
AMD-8111 SMBus 2.0 controller) are all SMBus 2.0 controllers,
and need another implementation of SMBus access methods, while
this driver supports AMD-756 SMBus 1.0 controller and clones,
including AMD-8111 SMBus 1.0 controller.
Tested by: Vladimir Timofeev (0x006410de),
mezz (0x008410de),
ru (0x00d410de)
All of us got the same(!) nonsense when running ``mbmon -S'',
repeated every four rows.
really should be a fptrdiff_t if we had that) in profclock().
- Don't try to profile kernel pc's that are >= the kernel lowpc to avoid
underflows when computing a profiling index.
- Use the PC_TO_I() macro to compute the kernel profiling index rather than
doing it inline.
Discussed with: bde
on probationary terms: it may go away again if it transpires it is
a bad idea.
This extensible printf version will only be used if either
environment variable USE_XPRINTF is defined
or
one of the extension functions are called.
or
the global variable __use_xprintf is set greater than zero.
In all other cases our traditional printf implementation will
be used.
The extensible version is slower than the default printf, mostly
because less opportunity for combining I/O operation exists when
faced with extensions. The default printf on the other hand
is a bad case of spaghetti code.
The extension API has a GLIBC compatible part and a FreeBSD version
of same. The FreeBSD version exists because the GLIBC version may
run afoul of our FILE * locking in multithreaded programs and it
even further eliminate the opportunities for combining I/O operations.
Include three demo extensions which can be enabled if desired: time
(%T), hexdump (%H) and strvis (%V).
%T can format time_t (%T), struct timeval (%lT) and struct timespec (%llT)
in one of two human readable duration formats:
"%.3llT" -> "20349.245"
"%#.3llT" -> "5h39m9.245"
%H will hexdump a sequence of bytes and takes a pointer and a length
argument. The width specifies number of bytes per line.
"%4H" -> "65 72 20 65"
"%+4H" -> "0000 65 72 20 65"
"%#4H" -> "65 72 20 65 |er e|"
"%+#4H" -> "0000 65 72 20 65 |er e|"
%V will dump a string in strvis format.
"%V" -> "Hello\tWor\377ld" (C-style)
"%0V" -> "Hello\011Wor\377ld" (octal)
"%+V" -> "Hello%09Wor%FFld" (http-style)
Tests, comments, bugreports etc are most welcome.
ephemeral mappings that are used as the source for three copy
operations from kernel space to user space. There are two reasons for
making this change: (1) Under heavy load exec_map can fill up causing
vm_map_find() to fail. When it fails, the nascent process is aborted
(SIGABRT). Whereas, this reimplementation using sf_buf_alloc()
sleeps. (2) Although it is possible to sleep on vm_map_find()'s
failure until address space becomes available (see kmem_alloc_wait()),
using sf_buf_alloc() is faster. Furthermore, the reimplementation
uses a CPU private mapping, avoiding a TLB shootdown on
multiprocessors.
Problem uncovered by: kris@
Reviewed by: tegge@
MFC after: 3 weeks
