FreeBSD src
d2012f3333
instead of 32+32+15+1) on all arches that have such long doubles (amd64, ia64 and i386). Large objects should be be accessed in large units, and the 32+32+15+1[+padding] decomposition asks for almost the opposite of that, sometimes resulting in very slow accesses depending on how well the compiler ignores what we ask for and converts to the best units for the given machine. E.g., on Athlons, there is a 10-20 cycle penalty for accessing the middle 32-bit word immediately after an 80-bit store. Whether actually using the alternative view is better is very machine- dependent. A 32+32+16 view is probably best with old 32-bit systems and gcc through 4.2.1. The compiler should mostly avoid the view and generate best accesses, but gcc-4.2.1 is far from doing that. I think 64+16 is best for now. Similarly for doubles -- they should be using 64+0 especially on 64-bit machines, but fdlibm uses 32+32 extensively for them. Fortunately, in 64-bit mode for doubles, gcc already ignores the 32+32-bit view and generates best accesses in many cases. |
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| bin | ||
| cddl | ||
| compat/opensolaris | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| ObsoleteFiles.inc | ||
| README | ||
| UPDATING | ||
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, the most commonly used one being ``world'', which rebuilds and installs everything in the FreeBSD system from the source tree except the kernel, the kernel-modules and the contents of /etc. The ``world'' target should only be used in cases where the source tree has not changed from the currently running version. See: 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, documentation for which can be found at: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html And in the config(8) man page. 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 sample kernel configuration files reside in the sys/<arch>/conf sub-directory (assuming that you've installed the kernel sources), the file named GENERIC being the one used to build your initial installation kernel. The file NOTES contains entries and documentation for all possible devices, not just those commonly used. It is the successor of the ancient LINT file, but in contrast to LINT, it is not buildable as a kernel but a pure reference and documentation file. Source Roadmap: --------------- bin System/user commands. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. games Amusements. 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. 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