r256631 - in /trunk/gcc: ChangeLog config/aarch...

[rsandifo@gcc.gnu.org]

Author: rsandifo
Date: Sat Jan 13 17:59:40 2018
New Revision: 256631

URL: https://gcc.gnu.org/viewcvs?rev=256631&root=gcc&view=rev
Log:
Add an empty_mask_is_expensive hook

This patch adds a hook to control whether we avoid executing masked
(predicated) stores when the mask is all false.  We don't want to do
that by default for SVE.

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

gcc/
	* target.def (empty_mask_is_expensive): New hook.
	* doc/tm.texi.in (TARGET_VECTORIZE_EMPTY_MASK_IS_EXPENSIVE): New hook.
	* doc/tm.texi: Regenerate.
	* targhooks.h (default_empty_mask_is_expensive): Declare.
	* targhooks.c (default_empty_mask_is_expensive): New function.
	* tree-vectorizer.c (vectorize_loops): Only call optimize_mask_stores
	if the target says that empty masks are expensive.
	* config/aarch64/aarch64.c (aarch64_empty_mask_is_expensive):
	New function.
	(TARGET_VECTORIZE_EMPTY_MASK_IS_EXPENSIVE): Redefine.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/aarch64/aarch64.c
    trunk/gcc/doc/tm.texi
    trunk/gcc/doc/tm.texi.in
    trunk/gcc/target.def
    trunk/gcc/targhooks.c
    trunk/gcc/targhooks.h
    trunk/gcc/tree-vectorizer.c