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Richard Sandiford 5a783f42d7 aarch64: Add a minipass for fusing CC insns [PR88836]
This patch adds a small target-specific pass to remove redundant SVE
PTEST instructions.  There are two important uses of this:

- Removing PTESTs after WHILELOs (PR88836).  The original testcase
  no longer exhibits the problem due to more recent optimisations,
  but it can still be seen in simple cases like the one in the patch.
  It also shows up in 450.soplex.

- Removing PTESTs after RDFFRs in ACLE code.

This is just an interim “solution” for GCC 11.  I hope to replace
it with something generic and target-independent for GCC 12.
However, the use cases above are very important for performance,
so I'd rather not leave the bug unfixed for yet another release cycle.

Since the pass is intended to be short-lived, I've not added
a command-line option for it.  The pass can be disabled using
-fdisable-rtl-cc_fusion if necessary.

Although what the pass does is independent of SVE, it's motivated
only by SVE cases and doesn't trigger for any non-SVE test I've seen.
I've therefore gated it on TARGET_SVE and restricted it to PTEST
patterns.

gcc/
	PR target/88836
	* config.gcc (aarch64*-*-*): Add aarch64-cc-fusion.o to extra_objs.
	* Makefile.in (RTL_SSA_H): New variable.
	* config/aarch64/t-aarch64 (aarch64-cc-fusion.o): New rule.
	* config/aarch64/aarch64-protos.h (make_pass_cc_fusion): Declare.
	* config/aarch64/aarch64-passes.def: Add pass_cc_fusion after
	pass_combine.
	* config/aarch64/aarch64-cc-fusion.cc: New file.

gcc/testsuite/
	PR target/88836
	* gcc.target/aarch64/sve/acle/general/ldff1_8.c: New test.
	* gcc.target/aarch64/sve/ptest_1.c: Likewise.
2021-01-15 16:45:42 +00:00
c++tools Daily bump. 2021-01-06 00:16:55 +00:00
config Daily bump. 2021-01-06 00:16:55 +00:00
contrib Daily bump. 2021-01-15 00:16:28 +00:00
fixincludes Daily bump. 2020-12-15 00:16:35 +00:00
gcc aarch64: Add a minipass for fusing CC insns [PR88836] 2021-01-15 16:45:42 +00:00
gnattools
gotools Daily bump. 2020-12-31 00:16:29 +00:00
include Update copyright years. 2021-01-04 10:26:59 +01:00
INSTALL
intl intl: Unbreak intl build with bison 3 when no regeneration is needed [PR92008] 2020-04-16 11:55:00 +02:00
libada Update copyright years. 2021-01-04 10:26:59 +01:00
libatomic libatomic, libgomp, libitc: Fix bootstrap [PR70454] 2021-01-15 13:16:42 +01:00
libbacktrace Daily bump. 2021-01-06 00:16:55 +00:00
libcc1 Daily bump. 2021-01-06 00:16:55 +00:00
libcody Daily bump. 2021-01-13 00:16:36 +00:00
libcpp Daily bump. 2021-01-08 00:16:23 +00:00
libdecnumber Update copyright years. 2021-01-04 10:26:59 +01:00
libffi Daily bump. 2021-01-06 00:16:55 +00:00
libgcc Daily bump. 2021-01-14 00:16:24 +00:00
libgfortran Daily bump. 2021-01-06 00:16:55 +00:00
libgo libgo: update hurd support 2021-01-14 09:57:04 -08:00
libgomp libatomic, libgomp, libitc: Fix bootstrap [PR70454] 2021-01-15 13:16:42 +01:00
libhsail-rt Daily bump. 2021-01-06 00:16:55 +00:00
libiberty Daily bump. 2021-01-05 00:16:42 +00:00
libitm libatomic, libgomp, libitc: Fix bootstrap [PR70454] 2021-01-15 13:16:42 +01:00
libobjc Daily bump. 2021-01-06 00:16:55 +00:00
liboffloadmic Daily bump. 2021-01-06 00:16:55 +00:00
libphobos Daily bump. 2021-01-06 00:16:55 +00:00
libquadmath Daily bump. 2021-01-06 00:16:55 +00:00
libsanitizer Daily bump. 2021-01-06 00:16:55 +00:00
libssp Daily bump. 2021-01-06 00:16:55 +00:00
libstdc++-v3 Daily bump. 2021-01-15 00:16:28 +00:00
libvtv Daily bump. 2021-01-06 00:16:55 +00:00
lto-plugin Daily bump. 2021-01-06 00:16:55 +00:00
maintainer-scripts Daily bump. 2020-12-17 00:16:37 +00:00
zlib Daily bump. 2021-01-06 00:16:55 +00:00
.dir-locals.el .dir-locals.el: Set 'fill-column' to 80 for c-mode 2020-12-14 12:19:56 +01:00
.gitattributes
.gitignore Sync .gitignore with binutils-gdb 2020-12-02 11:04:01 -07:00
ABOUT-NLS
ar-lib
ChangeLog Daily bump. 2021-01-13 00:16:36 +00:00
ChangeLog.jit
ChangeLog.tree-ssa
compile
config-ml.in config-ml.in: Suppress output from multi-do recipes 2020-11-09 14:28:37 +00:00
config.guess config.sub, config.guess : Import upstream 2020-11-07. 2020-11-23 19:30:01 +00:00
config.rpath
config.sub config.sub, config.guess : Import upstream 2020-11-07. 2020-11-23 19:30:01 +00:00
configure Add C++tools 2020-12-15 07:42:59 -08:00
configure.ac Add C++tools 2020-12-15 07:42:59 -08:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.RUNTIME
depcomp
install-sh
libtool-ldflags
libtool.m4 Update GNU/Hurd configure support 2021-01-05 16:04:14 -07:00
lt~obsolete.m4
ltgcc.m4
ltmain.sh Do not use HAVE_DOS_BASED_FILE_SYSTEM for Cygwin. 2020-04-17 09:22:51 +02:00
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS MAINTAINERS: Fix spacing 2021-01-12 18:41:43 +00:00
Makefile.def sync libctf toplevel from binutils-gdb 2021-01-07 09:28:58 +10:30
Makefile.in sync libctf toplevel from binutils-gdb 2021-01-07 09:28:58 +10:30
Makefile.tpl Add C++tools 2020-12-15 07:42:59 -08:00
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