e919fae01b
Under extreme register pressure, compiler can use FP <--> int
moves as a cheap alternate to spilling to memory.
This was seen with SPEC2017 FP benchmark 507.cactu:
ML_BSSN_Advect.cc:ML_BSSN_Advect_Body()
| fmv.d.x fa5,s9 # PDupwindNthSymm2Xt1, PDupwindNthSymm2Xt1
| .LVL325:
| ld s9,184(sp) # _12469, %sfp
| ...
| .LVL339:
| fmv.x.d s4,fa5 # PDupwindNthSymm2Xt1, PDupwindNthSymm2Xt1
|
The FMV instructions could be costlier (than stack spill) on certain
micro-architectures, thus this needs to be a per-cpu tunable
(default being to inhibit on all existing RV cpus).
Testsuite run with new test reports 10 failures without the fix
corresponding to the build variations of pr105666.c
| === gcc Summary ===
|
| # of expected passes 123318 (+10)
| # of unexpected failures 34 (-10)
| # of unexpected successes 4
| # of expected failures 780
| # of unresolved testcases 4
| # of unsupported tests 2796
gcc/ChangeLog:
* config/riscv/riscv.cc: (struct riscv_tune_param): Add
fmv_cost.
(rocket_tune_info): Add default fmv_cost 8.
(sifive_7_tune_info): Ditto.
(thead_c906_tune_info): Ditto.
(optimize_size_tune_info): Ditto.
(riscv_register_move_cost): Use fmv_cost for int<->fp moves.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/pr105666.c: New test.
Signed-off-by: Vineet Gupta <vineetg@rivosinc.com>
(cherry picked from commit
|
||
|---|---|---|
| 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.