864c28cf81
optimization. This fixes building with gcc-4.2.1 (it doesn't support SSE4). gas-2.17.50 [FreeBSD] supports SSE4 instructions, so this doesn't need using .byte directives. This fixes depending on host user headers in the kernel. Fix user includes (don't depend on namespace pollution in <nmmintrin.h> that is not included now). The instrinsics had no advantages except to sometimes avoid compiler pessimixations. clang understands them a bit better than inline asm, and generates better looking code which also runs better for cem, but for me it just at the same speed or slower by doing excessive unrollowing in all the wrong places. gcc-4.2.1 also doesn't understand what it is doing with unrolling, but with -O3 somehow it does more unrolling that helps. Reduce 1 of the the compiler pessimizations (copying a variable which already satisfies an "rm" constraint in a good way by being in memory and not used again, to different memory and accessing it there. Force copying it to a register instead). Try to optimize the inner loops significantly, so as to run at full speed on smaller inputs. The algorithm is already very MD, and was tuned for the throughput of 3 crc32 instructions per cycle found on at least Sandybridge through Haswell. Now it is even more tuned for this, so depends more on the compiler not rearranging or unrolling things too much. The main inner loop for should have no difficulty runing at full speed on these CPUs unless the compiler unrolls it too much. However, the main inner loop wasn't even used for buffers smaller than 24K. Now it is used for buffers larger than 384 bytes. Now it is not so long, and the main outer loop is used more. The new optimization is to try to arrange that the outer loop runs in parallel with the next inner loop except for the final iteration; then reduce the loop sizes significantly to take advantage of this. Approved by: cem Not tested in production by: bde |
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| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| ObsoleteFiles.inc | ||
| README | ||
| README.md | ||
| UPDATING | ||
FreeBSD Source:
This is the top level of the FreeBSD source directory. This file
was last revised on:
FreeBSD
For copyright information, please see the file COPYRIGHT in this directory (additional copyright information also exists for some sources in this tree - please see the specific source directories for more information).
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7) and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables.
The buildkernel and installkernel targets build and install
the kernel and the modules (see below). Please see the top of
the Makefile in this directory for more information on the
standard build targets and compile-time flags.
Building a kernel is a somewhat more involved process. See build(7), config(8), and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information.
Note: If you want to build and install the kernel with the
buildkernel and installkernel targets, you might need to build
world before. More information is available in the handbook.
The kernel configuration files reside in the sys/<arch>/conf
sub-directory. GENERIC is the default configuration used in release builds.
NOTES contains entries and documentation for all possible
devices, not just those commonly used.
Source Roadmap:
bin System/user commands.
cddl Various commands and libraries under the Common Development
and Distribution License.
contrib Packages contributed by 3rd parties.
crypto Cryptography stuff (see crypto/README).
etc Template files for /etc.
gnu Various commands and libraries under the GNU Public License.
Please see gnu/COPYING* for more information.
include System include files.
kerberos5 Kerberos5 (Heimdal) package.
lib System libraries.
libexec System daemons.
release Release building Makefile & associated tools.
rescue Build system for statically linked /rescue utilities.
sbin System commands.
secure Cryptographic libraries and commands.
share Shared resources.
sys Kernel sources.
tests Regression tests which can be run by Kyua. See tests/README
for additional information.
tools Utilities for regression testing and miscellaneous tasks.
usr.bin User commands.
usr.sbin System administration commands.
For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html