9a0882ef6a
We already have two splay tree implementations: the old C one in libiberty and a templated reimplementation of it in typed-splay-tree.h. However, they have some drawbacks: - They hard-code the assumption that nodes should have both a key and a value, which isn't always true. - They use the two-phase method of lookup, and so nodes need to store a temporary back pointer. We can avoid that overhead by using the top-down method (as e.g. the bitmap tree code already does). - The tree node has to own the key and the value. For some use cases it's more convenient to embed the tree links in the value instead. Also, a later patch wants to use splay trees to represent an adaptive total order: the splay tree itself records whether node N1 is less than node N2, and (in the worst case) comparing nodes is a splay operation. This patch therefore adds an alternative implementation. The main features are: - Nodes can optionally point back to their parents. - An Accessors class abstracts accessing child nodes and (where applicable) parent nodes, so that the information can be embedded in larger data structures. - There is no fixed comparison function at the class level. Instead, individual functions that do comparisons take a comparison function argument. - There are two styles of comparison function, optimised for different use cases. (See the comments in the patch for details.) - It's possible to do some operations directly on a given node, without knowing whether it's the root. This includes the comparison use case described above. This of course has its own set of drawbacks. It's really providing splay utility functions rather than a true ADT, and so is more low-level than the existing routines. It's mostly geared for cases in which the client code wants to participate in the splay operations to some extent. gcc/ * Makefile.in (OBJS): Add splay-tree-utils.o. * system.h: Include <array> when INCLUDE_ARRAY is defined. * selftest.h (splay_tree_cc_tests): Declare. * selftest-run-tests.c (selftest::run_tests): Run splay_tree_cc_tests. * splay-tree-utils.h: New file. * splay-tree-utils.tcc: Likewise. * splay-tree-utils.cc: Likewise. |
||
|---|---|---|
| c++tools | ||
| config | ||
| contrib | ||
| fixincludes | ||
| gcc | ||
| gnattools | ||
| gotools | ||
| include | ||
| INSTALL | ||
| intl | ||
| libada | ||
| libatomic | ||
| libbacktrace | ||
| libcc1 | ||
| libcody | ||
| libcpp | ||
| libdecnumber | ||
| libffi | ||
| libgcc | ||
| libgfortran | ||
| libgo | ||
| libgomp | ||
| libhsail-rt | ||
| libiberty | ||
| libitm | ||
| libobjc | ||
| liboffloadmic | ||
| libphobos | ||
| libquadmath | ||
| libsanitizer | ||
| libssp | ||
| libstdc++-v3 | ||
| libvtv | ||
| lto-plugin | ||
| maintainer-scripts | ||
| zlib | ||
| .dir-locals.el | ||
| .gitattributes | ||
| .gitignore | ||
| ABOUT-NLS | ||
| ar-lib | ||
| ChangeLog | ||
| ChangeLog.jit | ||
| ChangeLog.tree-ssa | ||
| compile | ||
| config-ml.in | ||
| config.guess | ||
| config.rpath | ||
| config.sub | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
| COPYING3 | ||
| COPYING3.LIB | ||
| COPYING.LIB | ||
| COPYING.RUNTIME | ||
| depcomp | ||
| install-sh | ||
| libtool-ldflags | ||
| libtool.m4 | ||
| lt~obsolete.m4 | ||
| ltgcc.m4 | ||
| ltmain.sh | ||
| ltoptions.m4 | ||
| ltsugar.m4 | ||
| ltversion.m4 | ||
| MAINTAINERS | ||
| Makefile.def | ||
| Makefile.in | ||
| Makefile.tpl | ||
| missing | ||
| mkdep | ||
| mkinstalldirs | ||
| move-if-change | ||
| multilib.am | ||
| README | ||
| symlink-tree | ||
| test-driver | ||
| ylwrap | ||
This directory contains the GNU Compiler Collection (GCC). The GNU Compiler Collection is free software. See the files whose names start with COPYING for copying permission. The manuals, and some of the runtime libraries, are under different terms; see the individual source files for details. The directory INSTALL contains copies of the installation information as HTML and plain text. The source of this information is gcc/doc/install.texi. The installation information includes details of what is included in the GCC sources and what files GCC installs. See the file gcc/doc/gcc.texi (together with other files that it includes) for usage and porting information. An online readable version of the manual is in the files gcc/doc/gcc.info*. See http://gcc.gnu.org/bugs/ for how to report bugs usefully. Copyright years on GCC source files may be listed using range notation, e.g., 1987-2012, indicating that every year in the range, inclusive, is a copyrightable year that could otherwise be listed individually.