7f5617b004
The following patch adds support for bitfields to push_partial_def. Previously pd.offset and pd.size were counted in bytes and maxsizei in bits, now everything is counted in bits. Not really sure how much of the further code can be outlined and moved, e.g. the full def and partial def code doesn't have pretty much anything in common (the partial defs case basically have some load bit range and a set of store bit ranges that at least partially overlap and we need to handle all the different cases, like negative pd.offset or non-negative, little vs. bit endian, size so small that we need to preserve original bits on both sides of the byte, size that fits or is too large. Perhaps the storing of some value into a middle of existing buffer (i.e. what push_partial_def now does in the loop) could, but the candidate for sharing would be most likely store-merging rather than the other spots in sccvn, and I think it is better not to touch store-merging at this stage. Yes, I've thought about trying to do everything in place, but the code is quite hard to understand and get right already now and if we tried to do the optimize on the fly, it would need more special cases and would for gcov coverage need more testcases to cover it. Most of the time the sizes will be small. Furthermore, for bitfields native_encode_expr stores actually number of bytes in the mode and not say actual bitsize rounded up to bytes, so it wouldn't be just a matter of saving/restoring bytes at the start and end, but we might need even 7 further bytes e.g. for __int128 bitfields. Perhaps we could have just a fast path for the case where everything is byte aligned and (for integral types the mode bitsize is equal to the size too)? 2020-02-24 Jakub Jelinek <jakub@redhat.com> PR tree-optimization/93582 * tree-ssa-sccvn.c (vn_walk_cb_data::push_partial_def): Consider pd.offset and pd.size to be counted in bits rather than bytes, add support for maxsizei that is not a multiple of BITS_PER_UNIT and handle bitfield stores and loads. (vn_reference_lookup_3): Don't call ranges_known_overlap_p with uncomparable quantities - bytes vs. bits. Allow push_partial_def on offsets/sizes that aren't multiple of BITS_PER_UNIT and adjust pd.offset/pd.size to be counted in bits rather than bytes. Formatting fix. Rename shadowed len variable to buflen. * gcc.dg/tree-ssa/pr93582-4.c: New test. * gcc.dg/tree-ssa/pr93582-5.c: New test. * gcc.dg/tree-ssa/pr93582-6.c: New test. * gcc.dg/tree-ssa/pr93582-7.c: New test. * gcc.dg/tree-ssa/pr93582-8.c: New test. |
||
|---|---|---|
| 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 | ||
| 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 | ||
| 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 | ||
| 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.