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Vineet Gupta ecfa870ff2 RISC-V: optim const DF +0.0 store to mem [PR/110748] 
Fixes: ef85d150b5 ("RISC-V: Enable TARGET_SUPPORTS_WIDE_INT")

DF +0.0 is bitwise all zeros so int x0 store to mem can be used to optimize it.

void zd(double *) { *d = 0.0; }

currently:

| fmv.d.x fa5,zero
| fsd     fa5,0(a0)
| ret

With patch

| sd      zero,0(a0)
| ret

The fix updates predicate const_0_operand() so reg_or_0_operand () now
includes const_double, enabling movdf expander -> riscv_legitimize_move ()
to generate below vs. an intermediate set (reg:DF) const_double:DF

| (insn 6 3 0 2 (set (mem:DF (reg/v/f:DI 134 [ d ])
|        (const_double:DF 0.0 [0x0.0p+0]))

This change also enables such insns to be recog() by later passes.
The md pattern "*movdf_hardfloat_rv64" despite already supporting the
needed constraints {"m","G"} mem/const 0.0 was failing to match because
the additional condition check reg_or_0_operand() was failing due to
missing const_double.

This failure to recog() was triggering an ICE when testing the in-flight
f-m-o patches and is how all of this started, but then was deemed to be
an independent optimization of it's own [1].

[1] https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624857.html

Its worthwhile to note all the set peices were already there and working
up until my own commit mentioned at top regressed the whole thing.

Ran thru full multilib testsuite and no surprises. There was 1 false
failure due to random string "lw" appearing in lto build assembler output,
which is also fixed here.

gcc/ChangeLog:

	PR target/110748
	* config/riscv/predicates.md (const_0_operand): Add back
	const_double.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/pr110748-1.c: New Test.
	* gcc.target/riscv/xtheadfmv-fmv.c: Add '\t' around test
	patterns to avoid random string matches.

Signed-off-by: Vineet Gupta <vineetg@rivosinc.com>
2023-07-22 14:44:02 -07:00
c++tools Daily bump. 2023-06-23 00:16:38 +00:00
config Daily bump. 2023-07-22 00:17:44 +00:00
contrib Daily bump. 2023-07-14 00:16:43 +00:00
fixincludes Daily bump. 2023-06-16 00:17:18 +00:00
gcc RISC-V: optim const DF +0.0 store to mem [PR/110748] 2023-07-22 14:44:02 -07:00
gnattools Daily bump. 2023-04-26 00:17:46 +00:00
gotools Daily bump. 2022-08-31 00:16:45 +00:00
include Daily bump. 2023-06-13 00:17:29 +00:00
INSTALL
intl Daily bump. 2023-06-16 00:17:18 +00:00
libada Update copyright years. 2023-01-16 11:52:17 +01:00
libatomic Daily bump. 2023-06-11 00:17:37 +00:00
libbacktrace Daily bump. 2023-03-29 00:17:01 +00:00
libcc1 Daily bump. 2023-05-19 00:17:43 +00:00
libcody Daily bump. 2023-06-16 00:17:18 +00:00
libcpp Daily bump. 2023-07-20 00:17:53 +00:00
libdecnumber Daily bump. 2023-06-16 00:17:18 +00:00
libffi Daily bump. 2023-05-07 00:16:40 +00:00
libgcc Daily bump. 2023-07-20 00:17:53 +00:00
libgfortran Daily bump. 2023-07-22 00:17:44 +00:00
libgm2 Daily bump. 2023-06-03 00:16:48 +00:00
libgo cmd/go: don't collect package CGOLDFLAGS when using gccgo 2023-07-20 12:29:11 -07:00
libgomp Daily bump. 2023-07-21 00:17:07 +00:00
libiberty Daily bump. 2023-06-16 00:17:18 +00:00
libitm Daily bump. 2023-06-03 00:16:48 +00:00
libobjc Daily bump. 2023-05-23 00:17:11 +00:00
libphobos Daily bump. 2023-07-11 00:16:56 +00:00
libquadmath Daily bump. 2023-03-03 00:16:38 +00:00
libsanitizer Daily bump. 2023-05-01 00:16:44 +00:00
libssp Update copyright years. 2023-01-16 11:52:17 +01:00
libstdc++-v3 Daily bump. 2023-07-20 00:17:53 +00:00
libvtv Update copyright years. 2023-01-16 11:52:17 +01:00
lto-plugin Daily bump. 2023-07-01 00:18:32 +00:00
maintainer-scripts Daily bump. 2023-07-08 00:16:53 +00:00
zlib Daily bump. 2023-06-17 00:17:17 +00:00
.dir-locals.el
.gitattributes
.gitignore .gitignore: do not ignore config.h 2022-07-19 17:07:04 +03:00
ABOUT-NLS
ar-lib
ChangeLog Daily bump. 2023-07-22 00:17:44 +00:00
ChangeLog.jit
ChangeLog.tree-ssa
compile
config-ml.in
config.guess
config.rpath
config.sub
configure configure, Darwin: Ensure overrides to host-pie are passed to gcc configure. 2023-06-25 10:16:39 +01:00
configure.ac configure, Darwin: Ensure overrides to host-pie are passed to gcc configure. 2023-06-25 10:16:39 +01:00
COPYING
COPYING.LIB
COPYING.RUNTIME
COPYING3
COPYING3.LIB
depcomp
install-sh
libtool-ldflags
libtool.m4 Generic configury support for shared libs on VxWorks 2022-10-11 07:31:07 +00:00
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
lt~obsolete.m4
MAINTAINERS MAINTAINERS: Add myself to write after approval 2023-07-21 19:04:44 +01:00
Makefile.def configure, Darwin: Ensure overrides to host-pie are passed to gcc configure. 2023-06-25 10:16:39 +01:00
Makefile.in Collect both user and kernel events for autofdo tests and autoprofiledbootstrap 2023-07-07 13:06:28 -07:00
Makefile.tpl Collect both user and kernel events for autofdo tests and autoprofiledbootstrap 2023-07-07 13:06:28 -07:00
missing
mkdep
mkinstalldirs
move-if-change
multilib.am
README
symlink-tree
test-driver
ylwrap

README 

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.