82cd78f2c3
The removal of --param=max-fsm-thread-length is causing code explosion. I thought that --param=max-fsm-thread-path-insns was a better gague for path profitability than raw BB length, but it turns out that we don't take into account PHIs when estimating the number of statements. In this PR, we have a sequence of very large PHIs that have us traversing extremely large paths that blow up the compilation. We could fix this a couple of different ways. We could avoid traversing more than a certain number of PHI arguments, or ignore large PHIs altogether. The old implementation certainly had this knob, and we could cut things off before we even got to the ranger. We could also adjust the instruction estimation to take into account PHIs, but I'm sure we'll mess something else in the process ;-). The easiest thing to do is just restore the knob. At a later time we could tweak this further, for instance, disregarding empty blocks in the count. BTW, this is the reason I didn't chop things off in the lowlevel registry for all threaders: the forward threader can't really explore too deep paths, but it could theoretically get there while threading over empty blocks. This fixes 102814, 102852, and I bet it solves the Linux kernel cross compile issue. Tested on x86-64 Linux. gcc/ChangeLog: PR tree-optimization/102814 * doc/invoke.texi: Document --param=max-fsm-thread-length. * params.opt: Add --param=max-fsm-thread-length. * tree-ssa-threadbackward.c (back_threader_profitability::profitable_path_p): Fail on paths longer than max-fsm-thread-length. |
||
|---|---|---|
| c++tools | ||
| config | ||
| contrib | ||
| fixincludes | ||
| gcc | ||
| gnattools | ||
| gotools | ||
| include | ||
| INSTALL | ||
| intl | ||
| libada | ||
| libatomic | ||
| libbacktrace | ||
| libcc1 | ||
| libcody | ||
| libcpp | ||
| libdecnumber | ||
| libffi | ||
| libgcc | ||
| libgfortran | ||
| libgo | ||
| libgomp | ||
| 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.