Give the target more control over ARRAY_TYPE modes

So far we've used integer modes for LD[234] and ST[234] arrays.
That doesn't scale well to SVE, since the sizes aren't fixed at
compile time (and even if they were, we wouldn't want integers
to be so wide).

This patch lets the target use double-, triple- and quadruple-length
vectors instead.

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

gcc/
	* target.def (array_mode): New target hook.
	* doc/tm.texi.in (TARGET_ARRAY_MODE): New hook.
	* doc/tm.texi: Regenerate.
	* hooks.h (hook_optmode_mode_uhwi_none): Declare.
	* hooks.c (hook_optmode_mode_uhwi_none): New function.
	* tree-vect-data-refs.c (vect_lanes_optab_supported_p): Use
	targetm.array_mode.
	* stor-layout.c (mode_for_array): Likewise.  Support polynomial
	type sizes.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r256617

1 files changed, 8 insertions, 0 deletions

diff --git a/gcc/hooks.c b/gcc/hooks.c
index 90d74bb..6171960 100644
--- a/gcc/hooks.c
+++ b/gcc/hooks.c
@@ -525,3 +525,11 @@ hook_bool_mode_reg_class_t_reg_class_t_false (machine_mode, reg_class_t,
   return false;
 }
 
+/* Generic hook that takes a mode and an unsigned HOST_WIDE_INT and
+   returns no mode.  */
+
+opt_machine_mode
+hook_optmode_mode_uhwi_none (machine_mode, unsigned HOST_WIDE_INT)
+{
+  return opt_machine_mode ();
+}