Replace autovectorize_vector_sizes with autovectorize_vector_modes

This is another patch in the series to remove the assumption that
all modes involved in vectorisation have to be the same size.
Rather than have the target provide a list of vector sizes,
it makes the target provide a list of vector "approaches",
with each approach represented by a mode.

A later patch will pass this mode to targetm.vectorize.related_mode
to get the vector mode for a given element mode.  Until then, the modes
simply act as an alternative way of specifying the vector size.

2019-11-14  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* target.h (vector_sizes, auto_vector_sizes): Delete.
	(vector_modes, auto_vector_modes): New typedefs.
	* target.def (autovectorize_vector_sizes): Replace with...
	(autovectorize_vector_modes): ...this new hook.
	* doc/tm.texi.in (TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES):
	Replace with...
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES): ...this new hook.
	* doc/tm.texi: Regenerate.
	* targhooks.h (default_autovectorize_vector_sizes): Delete.
	(default_autovectorize_vector_modes): New function.
	* targhooks.c (default_autovectorize_vector_sizes): Delete.
	(default_autovectorize_vector_modes): New function.
	* omp-general.c (omp_max_vf): Use autovectorize_vector_modes instead
	of autovectorize_vector_sizes.  Use the number of units in the mode
	to calculate the maximum VF.
	* omp-low.c (omp_clause_aligned_alignment): Use
	autovectorize_vector_modes instead of autovectorize_vector_sizes.
	Use a loop based on related_mode to iterate through all supported
	vector modes for a given scalar mode.
	* optabs-query.c (can_vec_mask_load_store_p): Use
	autovectorize_vector_modes instead of autovectorize_vector_sizes.
	* tree-vect-loop.c (vect_analyze_loop, vect_transform_loop): Likewise.
	* tree-vect-slp.c (vect_slp_bb_region): Likewise.
	* config/aarch64/aarch64.c (aarch64_autovectorize_vector_sizes):
	Replace with...
	(aarch64_autovectorize_vector_modes): ...this new function.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES): Delete.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES): Define.
	* config/arc/arc.c (arc_autovectorize_vector_sizes): Replace with...
	(arc_autovectorize_vector_modes): ...this new function.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES): Delete.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES): Define.
	* config/arm/arm.c (arm_autovectorize_vector_sizes): Replace with...
	(arm_autovectorize_vector_modes): ...this new function.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES): Delete.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES): Define.
	* config/i386/i386.c (ix86_autovectorize_vector_sizes): Replace with...
	(ix86_autovectorize_vector_modes): ...this new function.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES): Delete.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES): Define.
	* config/mips/mips.c (mips_autovectorize_vector_sizes): Replace with...
	(mips_autovectorize_vector_modes): ...this new function.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES): Delete.
	(TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES): Define.

From-SVN: r278236

2 files changed, 15 insertions, 7 deletions

diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 3da1d65..037039a 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -6008,12 +6008,20 @@ against lower halves of vectors recursively until the specified mode is
 reached.  The default is @var{mode} which means no splitting.
 @end deftypefn
 
-@deftypefn {Target Hook} void TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES (vector_sizes *@var{sizes}, bool @var{all})
-If the mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} is not
-the only one that is worth considering, this hook should add all suitable
-vector sizes to @var{sizes}, in order of decreasing preference.  The first
-one should be the size of @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}.
-If @var{all} is true, add suitable vector sizes even when they are generally
+@deftypefn {Target Hook} void TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES (vector_modes *@var{modes}, bool @var{all})
+If using the mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}
+is not the only approach worth considering, this hook should add one mode to
+@var{modes} for each useful alternative approach.  These modes are then
+passed to @code{TARGET_VECTORIZE_RELATED_MODE} to obtain the vector mode
+for a given element mode.
+
+The modes returned in @var{modes} should use the smallest element mode
+possible for the vectorization approach that they represent, preferring
+integer modes over floating-poing modes in the event of a tie.  The first
+mode should be the @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} for its
+element mode.
+
+If @var{all} is true, add suitable vector modes even when they are generally
 not expected to be worthwhile.
 
 The hook does not need to do anything if the vector returned by
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 727b88c..73afd0a 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -4175,7 +4175,7 @@ address;  but often a machine-dependent strategy can generate better code.
 
 @hook TARGET_VECTORIZE_SPLIT_REDUCTION
 
-@hook TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES
+@hook TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES
 
 @hook TARGET_VECTORIZE_RELATED_MODE