cc33f880e5
while working on -fmalloc-dce I noticed that tree-ssa-dce.cc still has an outdated list of builtions that are known to not read memory that can be replaced by query to fnspec and modref. If I get things right, dce does some dead store removal, but only on those memory object that are non-aliased (automatic variabels with no address taken) and for all other memory addresses it resorts to mark_all_reaching_defs_necessary expecting DSE to do the rest. So we really want to only check if there are no memory reads at all rather then trying to understand them by parsing fnspec or modref summary. I did run testsuite ensuring that all builtins matched previously are still matched. There are few testcases where this check fails, due to type incompatibility. New code uses gimple_call_builtin while other just checked callee_decl. We test things like calling free() without parmeter which I don't think we want to care about, but there is also testase declaring void * calloc (long, long) where builtin declaration expects unsigned long. I am not sure if this case should not be allowed by gimple_call_builtin? Bootstrappe/regtested x86_64-linux. OK? gcc/ChangeLog: * ipa-modref.cc (ipa_modref_callee_reads_no_memory_p): New function. * ipa-modref.h (ipa_modref_callee_reads_no_memory_p): Declare * tree-ssa-dce.cc (propagate_necessity): Use it. |
||
|---|---|---|
| .forgejo | ||
| .github | ||
| c++tools | ||
| config | ||
| contrib | ||
| fixincludes | ||
| gcc | ||
| gnattools | ||
| gotools | ||
| include | ||
| INSTALL | ||
| libada | ||
| libatomic | ||
| libbacktrace | ||
| libcc1 | ||
| libcody | ||
| libcpp | ||
| libdecnumber | ||
| libffi | ||
| libgcc | ||
| libgfortran | ||
| libgm2 | ||
| libgo | ||
| libgomp | ||
| libgrust | ||
| libiberty | ||
| libitm | ||
| libobjc | ||
| libphobos | ||
| libquadmath | ||
| libsanitizer | ||
| libssp | ||
| libstdc++-v3 | ||
| libvtv | ||
| lto-plugin | ||
| maintainer-scripts | ||
| zlib | ||
| .b4-config | ||
| .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 | ||
| SECURITY.txt | ||
| 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.