r256632 - in /trunk/gcc: ChangeLog config/aarch...

[rsandifo@gcc.gnu.org]

Author: rsandifo
Date: Sat Jan 13 17:59:50 2018
New Revision: 256632

URL: https://gcc.gnu.org/viewcvs?rev=256632&root=gcc&view=rev
Log:
Add support for vectorising live-out values using SVE LASTB

This patch uses the SVE LASTB instruction to optimise cases in which
a value produced by the final scalar iteration of a vectorised loop is
live outside the loop.  Previously this situation would stop us from
using a fully-masked loop.

2018-01-13  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* doc/md.texi (extract_last_@var{m}): Document.
	* optabs.def (extract_last_optab): New optab.
	* internal-fn.def (EXTRACT_LAST): New internal function.
	* internal-fn.c (cond_unary_direct): New macro.
	(expand_cond_unary_optab_fn): Likewise.
	(direct_cond_unary_optab_supported_p): Likewise.
	* tree-vect-loop.c (vectorizable_live_operation): Allow fully-masked
	loops using EXTRACT_LAST.
	* config/aarch64/aarch64-sve.md (aarch64_sve_lastb<mode>): Rename to...
	(extract_last_<mode>): ...this optab.
	(vec_extract<mode><Vel>): Update accordingly.

gcc/testsuite/
	* gcc.target/aarch64/sve/live_1.c: New test.
	* gcc.target/aarch64/sve/live_1_run.c: Likewise.

Added:
    trunk/gcc/testsuite/gcc.target/aarch64/sve/live_1.c
    trunk/gcc/testsuite/gcc.target/aarch64/sve/live_1_run.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/aarch64/aarch64-sve.md
    trunk/gcc/doc/md.texi
    trunk/gcc/internal-fn.c
    trunk/gcc/internal-fn.def
    trunk/gcc/optabs.def
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-loop.c