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

17 files changed, 177 insertions, 122 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 70e50ae..218ce4c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,52 @@
 2019-11-14  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* 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.
+
+2019-11-14  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* tree-vect-stmts.c (vectorizable_shift): Check the number
 	of vector elements as well as the type mode when deciding
 	whether an op1_vectype is compatible.  Reuse the result of
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 0870d2c..d177541 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -15912,12 +15912,12 @@ aarch64_preferred_simd_mode (scalar_mode mode)
 /* Return a list of possible vector sizes for the vectorizer
    to iterate over.  */
 static void
-aarch64_autovectorize_vector_sizes (vector_sizes *sizes, bool)
+aarch64_autovectorize_vector_modes (vector_modes *modes, bool)
 {
   if (TARGET_SVE)
-    sizes->safe_push (BYTES_PER_SVE_VECTOR);
-  sizes->safe_push (16);
-  sizes->safe_push (8);
+    modes->safe_push (VNx16QImode);
+  modes->safe_push (V16QImode);
+  modes->safe_push (V8QImode);
 }
 
 /* Implement TARGET_MANGLE_TYPE.  */
@@ -21751,9 +21751,9 @@ aarch64_libgcc_floating_mode_supported_p
 #define TARGET_VECTORIZE_BUILTIN_VECTORIZED_FUNCTION \
   aarch64_builtin_vectorized_function
 
-#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES
-#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES \
-  aarch64_autovectorize_vector_sizes
+#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES
+#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES \
+  aarch64_autovectorize_vector_modes
 
 #undef TARGET_ATOMIC_ASSIGN_EXPAND_FENV
 #define TARGET_ATOMIC_ASSIGN_EXPAND_FENV \
diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
index c2d38dd..f48f102 100644
--- a/gcc/config/arc/arc.c
+++ b/gcc/config/arc/arc.c
@@ -607,15 +607,15 @@ arc_preferred_simd_mode (scalar_mode mode)
 }
 
 /* Implements target hook
-   TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES.  */
+   TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES.  */
 
 static void
-arc_autovectorize_vector_sizes (vector_sizes *sizes, bool)
+arc_autovectorize_vector_modes (vector_modes *modes, bool)
 {
   if (TARGET_PLUS_QMACW)
     {
-      sizes->quick_push (8);
-      sizes->quick_push (4);
+      modes->quick_push (V4HImode);
+      modes->quick_push (V2HImode);
     }
 }
 
@@ -726,8 +726,8 @@ static rtx arc_legitimize_address_0 (rtx, rtx, machine_mode mode);
 #undef TARGET_VECTORIZE_PREFERRED_SIMD_MODE
 #define TARGET_VECTORIZE_PREFERRED_SIMD_MODE arc_preferred_simd_mode
 
-#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES
-#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES arc_autovectorize_vector_sizes
+#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES
+#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES arc_autovectorize_vector_modes
 
 #undef TARGET_CAN_USE_DOLOOP_P
 #define TARGET_CAN_USE_DOLOOP_P arc_can_use_doloop_p
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index fea3882..70a20f7 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -288,7 +288,7 @@ static bool arm_builtin_support_vector_misalignment (machine_mode mode,
 static void arm_conditional_register_usage (void);
 static enum flt_eval_method arm_excess_precision (enum excess_precision_type);
 static reg_class_t arm_preferred_rename_class (reg_class_t rclass);
-static void arm_autovectorize_vector_sizes (vector_sizes *, bool);
+static void arm_autovectorize_vector_modes (vector_modes *, bool);
 static int arm_default_branch_cost (bool, bool);
 static int arm_cortex_a5_branch_cost (bool, bool);
 static int arm_cortex_m_branch_cost (bool, bool);
@@ -524,9 +524,9 @@ static const struct attribute_spec arm_attribute_table[] =
 #define TARGET_ARRAY_MODE_SUPPORTED_P arm_array_mode_supported_p
 #undef TARGET_VECTORIZE_PREFERRED_SIMD_MODE
 #define TARGET_VECTORIZE_PREFERRED_SIMD_MODE arm_preferred_simd_mode
-#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES
-#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES \
-  arm_autovectorize_vector_sizes
+#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES
+#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES \
+  arm_autovectorize_vector_modes
 
 #undef  TARGET_MACHINE_DEPENDENT_REORG
 #define TARGET_MACHINE_DEPENDENT_REORG arm_reorg
@@ -29016,12 +29016,12 @@ arm_vector_alignment (const_tree type)
 }
 
 static void
-arm_autovectorize_vector_sizes (vector_sizes *sizes, bool)
+arm_autovectorize_vector_modes (vector_modes *modes, bool)
 {
   if (!TARGET_NEON_VECTORIZE_DOUBLE)
     {
-      sizes->safe_push (16);
-      sizes->safe_push (8);
+      modes->safe_push (V16QImode);
+      modes->safe_push (V8QImode);
     }
 }
 
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 69c8278..c406be3 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -21385,35 +21385,35 @@ ix86_preferred_simd_mode (scalar_mode mode)
    256bit and 128bit vectors.  */
 
 static void
-ix86_autovectorize_vector_sizes (vector_sizes *sizes, bool all)
+ix86_autovectorize_vector_modes (vector_modes *modes, bool all)
 {
   if (TARGET_AVX512F && !TARGET_PREFER_AVX256)
     {
-      sizes->safe_push (64);
-      sizes->safe_push (32);
-      sizes->safe_push (16);
+      modes->safe_push (V64QImode);
+      modes->safe_push (V32QImode);
+      modes->safe_push (V16QImode);
     }
   else if (TARGET_AVX512F && all)
     {
-      sizes->safe_push (32);
-      sizes->safe_push (16);
-      sizes->safe_push (64);
+      modes->safe_push (V32QImode);
+      modes->safe_push (V16QImode);
+      modes->safe_push (V64QImode);
     }
   else if (TARGET_AVX && !TARGET_PREFER_AVX128)
     {
-      sizes->safe_push (32);
-      sizes->safe_push (16);
+      modes->safe_push (V32QImode);
+      modes->safe_push (V16QImode);
     }
   else if (TARGET_AVX && all)
     {
-      sizes->safe_push (16);
-      sizes->safe_push (32);
+      modes->safe_push (V16QImode);
+      modes->safe_push (V32QImode);
     }
   else if (TARGET_MMX_WITH_SSE)
-    sizes->safe_push (16);
+    modes->safe_push (V16QImode);
 
   if (TARGET_MMX_WITH_SSE)
-    sizes->safe_push (8);
+    modes->safe_push (V8QImode);
 }
 
 /* Implemenation of targetm.vectorize.get_mask_mode.  */
@@ -22952,9 +22952,9 @@ ix86_run_selftests (void)
 #undef TARGET_VECTORIZE_SPLIT_REDUCTION
 #define TARGET_VECTORIZE_SPLIT_REDUCTION \
   ix86_split_reduction
-#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES
-#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES \
-  ix86_autovectorize_vector_sizes
+#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES
+#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES \
+  ix86_autovectorize_vector_modes
 #undef TARGET_VECTORIZE_GET_MASK_MODE
 #define TARGET_VECTORIZE_GET_MASK_MODE ix86_get_mask_mode
 #undef TARGET_VECTORIZE_INIT_COST
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index e337b82..30017e3 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -13453,13 +13453,13 @@ mips_preferred_simd_mode (scalar_mode mode)
   return word_mode;
 }
 
-/* Implement TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES.  */
+/* Implement TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES.  */
 
 static void
-mips_autovectorize_vector_sizes (vector_sizes *sizes, bool)
+mips_autovectorize_vector_modes (vector_modes *modes, bool)
 {
   if (ISA_HAS_MSA)
-    sizes->safe_push (16);
+    modes->safe_push (V16QImode);
 }
 
 /* Implement TARGET_INIT_LIBFUNCS.  */
@@ -22716,9 +22716,9 @@ mips_starting_frame_offset (void)
 
 #undef TARGET_VECTORIZE_PREFERRED_SIMD_MODE
 #define TARGET_VECTORIZE_PREFERRED_SIMD_MODE mips_preferred_simd_mode
-#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES
-#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_SIZES \
-  mips_autovectorize_vector_sizes
+#undef TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES
+#define TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES \
+  mips_autovectorize_vector_modes
 
 #undef TARGET_INIT_BUILTINS
 #define TARGET_INIT_BUILTINS mips_init_builtins
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
 
diff --git a/gcc/omp-general.c b/gcc/omp-general.c
index 67ed345..a8efc10 100644
--- a/gcc/omp-general.c
+++ b/gcc/omp-general.c
@@ -516,13 +516,16 @@ omp_max_vf (void)
 	  && global_options_set.x_flag_tree_loop_vectorize))
     return 1;
 
-  auto_vector_sizes sizes;
-  targetm.vectorize.autovectorize_vector_sizes (&sizes, true);
-  if (!sizes.is_empty ())
+  auto_vector_modes modes;
+  targetm.vectorize.autovectorize_vector_modes (&modes, true);
+  if (!modes.is_empty ())
     {
       poly_uint64 vf = 0;
-      for (unsigned int i = 0; i < sizes.length (); ++i)
-	vf = ordered_max (vf, sizes[i]);
+      for (unsigned int i = 0; i < modes.length (); ++i)
+	/* The returned modes use the smallest element size (and thus
+	   the largest nunits) for the vectorization approach that they
+	   represent.  */
+	vf = ordered_max (vf, GET_MODE_NUNITS (modes[i]));
       return vf;
     }
 
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 781e7cb..3e470af 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -4064,11 +4064,8 @@ omp_clause_aligned_alignment (tree clause)
   /* Otherwise return implementation defined alignment.  */
   unsigned int al = 1;
   opt_scalar_mode mode_iter;
-  auto_vector_sizes sizes;
-  targetm.vectorize.autovectorize_vector_sizes (&sizes, true);
-  poly_uint64 vs = 0;
-  for (unsigned int i = 0; i < sizes.length (); ++i)
-    vs = ordered_max (vs, sizes[i]);
+  auto_vector_modes modes;
+  targetm.vectorize.autovectorize_vector_modes (&modes, true);
   static enum mode_class classes[]
     = { MODE_INT, MODE_VECTOR_INT, MODE_FLOAT, MODE_VECTOR_FLOAT };
   for (int i = 0; i < 4; i += 2)
@@ -4079,19 +4076,18 @@ omp_clause_aligned_alignment (tree clause)
 	machine_mode vmode = targetm.vectorize.preferred_simd_mode (mode);
 	if (GET_MODE_CLASS (vmode) != classes[i + 1])
 	  continue;
-	while (maybe_ne (vs, 0U)
-	       && known_lt (GET_MODE_SIZE (vmode), vs)
-	       && GET_MODE_2XWIDER_MODE (vmode).exists ())
-	  vmode = GET_MODE_2XWIDER_MODE (vmode).require ();
+	machine_mode alt_vmode;
+	for (unsigned int j = 0; j < modes.length (); ++j)
+	  if (related_vector_mode (modes[j], mode).exists (&alt_vmode)
+	      && known_ge (GET_MODE_SIZE (alt_vmode), GET_MODE_SIZE (vmode)))
+	    vmode = alt_vmode;
 
 	tree type = lang_hooks.types.type_for_mode (mode, 1);
 	if (type == NULL_TREE || TYPE_MODE (type) != mode)
 	  continue;
-	poly_uint64 nelts = exact_div (GET_MODE_SIZE (vmode),
-				       GET_MODE_SIZE (mode));
-	type = build_vector_type (type, nelts);
-	if (TYPE_MODE (type) != vmode)
-	  continue;
+	type = build_vector_type_for_mode (type, vmode);
+	/* The functions above are not allowed to return invalid modes.  */
+	gcc_assert (TYPE_MODE (type) == vmode);
 	if (TYPE_ALIGN_UNIT (type) > al)
 	  al = TYPE_ALIGN_UNIT (type);
       }
diff --git a/gcc/optabs-query.c b/gcc/optabs-query.c
index d59e116..fdca980 100644
--- a/gcc/optabs-query.c
+++ b/gcc/optabs-query.c
@@ -589,11 +589,11 @@ can_vec_mask_load_store_p (machine_mode mode,
       && convert_optab_handler (op, vmode, mask_mode) != CODE_FOR_nothing)
     return true;
 
-  auto_vector_sizes vector_sizes;
-  targetm.vectorize.autovectorize_vector_sizes (&vector_sizes, true);
-  for (unsigned int i = 0; i < vector_sizes.length (); ++i)
+  auto_vector_modes vector_modes;
+  targetm.vectorize.autovectorize_vector_modes (&vector_modes, true);
+  for (unsigned int i = 0; i < vector_modes.length (); ++i)
     {
-      poly_uint64 cur = vector_sizes[i];
+      poly_uint64 cur = GET_MODE_SIZE (vector_modes[i]);
       poly_uint64 nunits;
       if (!multiple_p (cur, GET_MODE_SIZE (smode), &nunits))
 	continue;
diff --git a/gcc/target.def b/gcc/target.def
index 51bc9a7..d220f8f 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -1909,20 +1909,28 @@ reached.  The default is @var{mode} which means no splitting.",
 /* Returns a mask of vector sizes to iterate over when auto-vectorizing
    after processing the preferred one derived from preferred_simd_mode.  */
 DEFHOOK
-(autovectorize_vector_sizes,
- "If the mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} is not\n\
-the only one that is worth considering, this hook should add all suitable\n\
-vector sizes to @var{sizes}, in order of decreasing preference.  The first\n\
-one should be the size of @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}.\n\
-If @var{all} is true, add suitable vector sizes even when they are generally\n\
+(autovectorize_vector_modes,
+ "If using the mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}\n\
+is not the only approach worth considering, this hook should add one mode to\n\
+@var{modes} for each useful alternative approach.  These modes are then\n\
+passed to @code{TARGET_VECTORIZE_RELATED_MODE} to obtain the vector mode\n\
+for a given element mode.\n\
+\n\
+The modes returned in @var{modes} should use the smallest element mode\n\
+possible for the vectorization approach that they represent, preferring\n\
+integer modes over floating-poing modes in the event of a tie.  The first\n\
+mode should be the @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} for its\n\
+element mode.\n\
+\n\
+If @var{all} is true, add suitable vector modes even when they are generally\n\
 not expected to be worthwhile.\n\
 \n\
 The hook does not need to do anything if the vector returned by\n\
 @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} is the only one relevant\n\
 for autovectorization.  The default implementation does nothing.",
  void,
- (vector_sizes *sizes, bool all),
- default_autovectorize_vector_sizes)
+ (vector_modes *modes, bool all),
+ default_autovectorize_vector_modes)
 
 DEFHOOK
 (related_mode,
diff --git a/gcc/target.h b/gcc/target.h
index 843c3d7..60757ef 100644
--- a/gcc/target.h
+++ b/gcc/target.h
@@ -205,11 +205,11 @@ enum vect_cost_model_location {
 class vec_perm_indices;
 
 /* The type to use for lists of vector sizes.  */
-typedef vec<poly_uint64> vector_sizes;
+typedef vec<machine_mode> vector_modes;
 
 /* Same, but can be used to construct local lists that are
    automatically freed.  */
-typedef auto_vec<poly_uint64, 8> auto_vector_sizes;
+typedef auto_vec<machine_mode, 8> auto_vector_modes;
 
 /* First argument of targetm.omp.device_kind_arch_isa.  */
 enum omp_device_kind_arch_isa {
diff --git a/gcc/targhooks.c b/gcc/targhooks.c
index f6c7a0c..b0362f9 100644
--- a/gcc/targhooks.c
+++ b/gcc/targhooks.c
@@ -1298,11 +1298,10 @@ default_split_reduction (machine_mode mode)
   return mode;
 }
 
-/* By default only the size derived from the preferred vector mode
-   is tried.  */
+/* By default only the preferred vector mode is tried.  */
 
 void
-default_autovectorize_vector_sizes (vector_sizes *, bool)
+default_autovectorize_vector_modes (vector_modes *, bool)
 {
 }
 
diff --git a/gcc/targhooks.h b/gcc/targhooks.h
index 57b83a3..7f96a7c 100644
--- a/gcc/targhooks.h
+++ b/gcc/targhooks.h
@@ -113,7 +113,7 @@ default_builtin_support_vector_misalignment (machine_mode mode,
 					     int, bool);
 extern machine_mode default_preferred_simd_mode (scalar_mode mode);
 extern machine_mode default_split_reduction (machine_mode);
-extern void default_autovectorize_vector_sizes (vector_sizes *, bool);
+extern void default_autovectorize_vector_modes (vector_modes *, bool);
 extern opt_machine_mode default_vectorize_related_mode (machine_mode,
 							scalar_mode,
 							poly_uint64);
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 8319cb1..77ae9f51 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -2382,12 +2382,12 @@ again:
 opt_loop_vec_info
 vect_analyze_loop (class loop *loop, vec_info_shared *shared)
 {
-  auto_vector_sizes vector_sizes;
+  auto_vector_modes vector_modes;
 
   /* Autodetect first vector size we try.  */
-  targetm.vectorize.autovectorize_vector_sizes (&vector_sizes,
+  targetm.vectorize.autovectorize_vector_modes (&vector_modes,
 						loop->simdlen != 0);
-  unsigned int next_size = 0;
+  unsigned int mode_i = 0;
 
   DUMP_VECT_SCOPE ("analyze_loop_nest");
 
@@ -2406,7 +2406,7 @@ vect_analyze_loop (class loop *loop, vec_info_shared *shared)
   unsigned n_stmts = 0;
   poly_uint64 autodetected_vector_size = 0;
   opt_loop_vec_info first_loop_vinfo = opt_loop_vec_info::success (NULL);
-  poly_uint64 next_vector_size = 0;
+  machine_mode next_vector_mode = VOIDmode;
   poly_uint64 lowest_th = 0;
   unsigned vectorized_loops = 0;
 
@@ -2425,7 +2425,7 @@ vect_analyze_loop (class loop *loop, vec_info_shared *shared)
 	  gcc_checking_assert (first_loop_vinfo == NULL);
 	  return loop_vinfo;
 	}
-      loop_vinfo->vector_size = next_vector_size;
+      loop_vinfo->vector_size = GET_MODE_SIZE (next_vector_mode);
 
       bool fatal = false;
 
@@ -2433,7 +2433,7 @@ vect_analyze_loop (class loop *loop, vec_info_shared *shared)
 	LOOP_VINFO_ORIG_LOOP_INFO (loop_vinfo) = first_loop_vinfo;
 
       res = vect_analyze_loop_2 (loop_vinfo, fatal, &n_stmts);
-      if (next_size == 0)
+      if (mode_i == 0)
 	autodetected_vector_size = loop_vinfo->vector_size;
 
       loop->aux = NULL;
@@ -2500,24 +2500,21 @@ vect_analyze_loop (class loop *loop, vec_info_shared *shared)
 	    }
 	}
 
-      if (next_size < vector_sizes.length ()
-	  && known_eq (vector_sizes[next_size], autodetected_vector_size))
-	next_size += 1;
+      if (mode_i < vector_modes.length ()
+	  && known_eq (GET_MODE_SIZE (vector_modes[mode_i]),
+		       autodetected_vector_size))
+	mode_i += 1;
 
-      if (next_size == vector_sizes.length ()
+      if (mode_i == vector_modes.length ()
 	  || known_eq (autodetected_vector_size, 0U))
 	break;
 
       /* Try the next biggest vector size.  */
-      next_vector_size = vector_sizes[next_size++];
+      next_vector_mode = vector_modes[mode_i++];
       if (dump_enabled_p ())
-	{
-	  dump_printf_loc (MSG_NOTE, vect_location,
-			   "***** Re-trying analysis with "
-			   "vector size ");
-	  dump_dec (MSG_NOTE, next_vector_size);
-	  dump_printf (MSG_NOTE, "\n");
-	}
+	dump_printf_loc (MSG_NOTE, vect_location,
+			 "***** Re-trying analysis with vector mode %s\n",
+			 GET_MODE_NAME (next_vector_mode));
     }
 
   if (first_loop_vinfo)
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 61a864e..b6d75f8 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -3172,12 +3172,12 @@ vect_slp_bb_region (gimple_stmt_iterator region_begin,
 		    unsigned int n_stmts)
 {
   bb_vec_info bb_vinfo;
-  auto_vector_sizes vector_sizes;
+  auto_vector_modes vector_modes;
 
   /* Autodetect first vector size we try.  */
-  poly_uint64 next_vector_size = 0;
-  targetm.vectorize.autovectorize_vector_sizes (&vector_sizes, false);
-  unsigned int next_size = 0;
+  machine_mode next_vector_mode = VOIDmode;
+  targetm.vectorize.autovectorize_vector_modes (&vector_modes, false);
+  unsigned int mode_i = 0;
 
   vec_info_shared shared;
 
@@ -3194,7 +3194,7 @@ vect_slp_bb_region (gimple_stmt_iterator region_begin,
 	bb_vinfo->shared->save_datarefs ();
       else
 	bb_vinfo->shared->check_datarefs ();
-      bb_vinfo->vector_size = next_vector_size;
+      bb_vinfo->vector_size = GET_MODE_SIZE (next_vector_mode);
 
       if (vect_slp_analyze_bb_1 (bb_vinfo, n_stmts, fatal)
 	  && dbg_cnt (vect_slp))
@@ -3221,17 +3221,18 @@ vect_slp_bb_region (gimple_stmt_iterator region_begin,
 	  vectorized = true;
 	}
 
-      if (next_size == 0)
+      if (mode_i == 0)
 	autodetected_vector_size = bb_vinfo->vector_size;
 
       delete bb_vinfo;
 
-      if (next_size < vector_sizes.length ()
-	  && known_eq (vector_sizes[next_size], autodetected_vector_size))
-	next_size += 1;
+      if (mode_i < vector_modes.length ()
+	  && known_eq (GET_MODE_SIZE (vector_modes[mode_i]),
+		       autodetected_vector_size))
+	mode_i += 1;
 
       if (vectorized
-	  || next_size == vector_sizes.length ()
+	  || mode_i == vector_modes.length ()
 	  || known_eq (autodetected_vector_size, 0U)
 	  /* If vect_slp_analyze_bb_1 signaled that analysis for all
 	     vector sizes will fail do not bother iterating.  */
@@ -3239,15 +3240,11 @@ vect_slp_bb_region (gimple_stmt_iterator region_begin,
 	return vectorized;
 
       /* Try the next biggest vector size.  */
-      next_vector_size = vector_sizes[next_size++];
+      next_vector_mode = vector_modes[mode_i++];
       if (dump_enabled_p ())
-	{
-	  dump_printf_loc (MSG_NOTE, vect_location,
-			   "***** Re-trying analysis with "
-			   "vector size ");
-	  dump_dec (MSG_NOTE, next_vector_size);
-	  dump_printf (MSG_NOTE, "\n");
-	}
+	dump_printf_loc (MSG_NOTE, vect_location,
+			 "***** Re-trying analysis with vector mode %s\n",
+			 GET_MODE_NAME (next_vector_mode));
     }
 }