GCC modified for the FreeChainXenon project
8d2d39587d
On most targets every function starts with moves from the parameter passing (hard) registers into pseudos. Similarly, after every call there is a move from the return register into a pseudo. These moves usually combine with later instructions (leaving pretty much the same instruction, just with a hard reg instead of a pseudo). This isn't a good idea. Register allocation can get rid of unnecessary moves just fine, and moving the parameter passing registers into many later instructions tends to prevent good register allocation. This patch disallows combining moves from a hard (non-fixed) register. This also avoid the problem mentioned in PR87600 #c3 (combining hard registers into inline assembler is problematic). Because the register move can often be combined with other instructions *itself*, for example for setting some condition code, this patch adds extra copies via new pseudos after every copy-from-hard-reg. On some targets this reduces average code size. On others it increases it a bit, 0.1% or 0.2% or so. (I tested this on all *-linux targets). PR rtl-optimization/87600 * combine.c: Add include of expr.h. (cant_combine_insn_p): Do not combine moves from any hard non-fixed register to a pseudo. (make_more_copies): New function, add a copy to a new pseudo after the moves from hard registers into pseudos. (rest_of_handle_combine): Declare rebuild_jump_labels_after_combine later. Call make_more_copies. From-SVN: r265398 |
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| config | ||
| contrib | ||
| fixincludes | ||
| gcc | ||
| gnattools | ||
| gotools | ||
| include | ||
| INSTALL | ||
| intl | ||
| libada | ||
| libatomic | ||
| libbacktrace | ||
| libcc1 | ||
| libcpp | ||
| libdecnumber | ||
| libffi | ||
| libgcc | ||
| libgfortran | ||
| libgo | ||
| libgomp | ||
| libhsail-rt | ||
| libiberty | ||
| libitm | ||
| libobjc | ||
| liboffloadmic | ||
| libquadmath | ||
| libsanitizer | ||
| libssp | ||
| libstdc++-v3 | ||
| libvtv | ||
| lto-plugin | ||
| maintainer-scripts | ||
| zlib | ||
| .dir-locals.el | ||
| .gitattributes | ||
| .gitignore | ||
| ABOUT-NLS | ||
| ChangeLog | ||
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| compile | ||
| config-ml.in | ||
| config.guess | ||
| config.rpath | ||
| config.sub | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
| COPYING.LIB | ||
| COPYING.RUNTIME | ||
| COPYING3 | ||
| COPYING3.LIB | ||
| depcomp | ||
| install-sh | ||
| libtool-ldflags | ||
| libtool.m4 | ||
| ltgcc.m4 | ||
| ltmain.sh | ||
| ltoptions.m4 | ||
| ltsugar.m4 | ||
| ltversion.m4 | ||
| lt~obsolete.m4 | ||
| MAINTAINERS | ||
| Makefile.def | ||
| Makefile.in | ||
| Makefile.tpl | ||
| missing | ||
| mkdep | ||
| mkinstalldirs | ||
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| README | ||
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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.