Fall back to masked_gather_load/masked_scatter_store

This adds a fallback to the masked_ variants for gather_load
and scatter_store if the latter are not available.

2021-08-17  Richard Biener  <rguenther@suse.de>

	* optabs-query.c (supports_vec_gather_load_p): Also check
	for masked optabs.
	(supports_vec_scatter_store_p): Likewise.
	* tree-vect-data-refs.c (vect_gather_scatter_fn_p): Fall
	back to masked variants if non-masked are not supported.
	* tree-vect-patterns.c (vect_recog_gather_scatter_pattern):
	When we need to use masked gather/scatter but do not have
	a mask set up a constant true one.
	* tree-vect-stmts.c (vect_check_scalar_mask): Also allow
	non-SSA_NAME masks.

4 files changed, 28 insertions, 15 deletions

diff --git a/gcc/optabs-query.c b/gcc/optabs-query.c
index 05ee5f5..a6dd0fe 100644
--- a/gcc/optabs-query.c
+++ b/gcc/optabs-query.c
@@ -740,7 +740,8 @@ supports_vec_gather_load_p ()
   this_fn_optabs->supports_vec_gather_load_cached = true;
 
   this_fn_optabs->supports_vec_gather_load
-    = supports_vec_convert_optab_p (gather_load_optab);
+    = (supports_vec_convert_optab_p (gather_load_optab)
+       || supports_vec_convert_optab_p (mask_gather_load_optab));
 
   return this_fn_optabs->supports_vec_gather_load;
 }
@@ -757,7 +758,8 @@ supports_vec_scatter_store_p ()
   this_fn_optabs->supports_vec_scatter_store_cached = true;
 
   this_fn_optabs->supports_vec_scatter_store
-    = supports_vec_convert_optab_p (scatter_store_optab);
+    = (supports_vec_convert_optab_p (scatter_store_optab)
+       || supports_vec_convert_optab_p (mask_scatter_store_optab));
 
   return this_fn_optabs->supports_vec_scatter_store;
 }
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index d594c0a..b7dde07 100644
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -3735,11 +3735,17 @@ vect_gather_scatter_fn_p (vec_info *vinfo, bool read_p, bool masked_p,
     return false;
 
   /* Work out which function we need.  */
-  internal_fn ifn;
+  internal_fn ifn, alt_ifn;
   if (read_p)
-    ifn = masked_p ? IFN_MASK_GATHER_LOAD : IFN_GATHER_LOAD;
+    {
+      ifn = masked_p ? IFN_MASK_GATHER_LOAD : IFN_GATHER_LOAD;
+      alt_ifn = IFN_MASK_GATHER_LOAD;
+    }
   else
-    ifn = masked_p ? IFN_MASK_SCATTER_STORE : IFN_SCATTER_STORE;
+    {
+      ifn = masked_p ? IFN_MASK_SCATTER_STORE : IFN_SCATTER_STORE;
+      alt_ifn = IFN_MASK_SCATTER_STORE;
+    }
 
   for (;;)
     {
@@ -3755,6 +3761,16 @@ vect_gather_scatter_fn_p (vec_info *vinfo, bool read_p, bool masked_p,
 	  *offset_vectype_out = offset_vectype;
 	  return true;
 	}
+      else if (!masked_p
+	       && internal_gather_scatter_fn_supported_p (alt_ifn, vectype,
+							  memory_type,
+							  offset_vectype,
+							  scale))
+	{
+	  *ifn_out = alt_ifn;
+	  *offset_vectype_out = offset_vectype;
+	  return true;
+	}
 
       if (TYPE_PRECISION (offset_type) >= POINTER_SIZE
 	  && TYPE_PRECISION (offset_type) >= element_bits)
diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c
index 25de97b..8997340 100644
--- a/gcc/tree-vect-patterns.c
+++ b/gcc/tree-vect-patterns.c
@@ -4820,6 +4820,9 @@ vect_recog_gather_scatter_pattern (vec_info *vinfo,
   if (mask)
     mask = vect_convert_mask_for_vectype (mask, gs_vectype, stmt_info,
 					  loop_vinfo);
+  else if (gs_info.ifn == IFN_MASK_SCATTER_STORE
+	   || gs_info.ifn == IFN_MASK_GATHER_LOAD)
+    mask = build_int_cst (TREE_TYPE (truth_type_for (gs_vectype)), -1);
 
   /* Get the invariant base and non-invariant offset, converting the
      latter to the same width as the vector elements.  */
@@ -4847,11 +4850,11 @@ vect_recog_gather_scatter_pattern (vec_info *vinfo,
     {
       tree rhs = vect_get_store_rhs (stmt_info);
       if (mask != NULL)
-	pattern_stmt = gimple_build_call_internal (IFN_MASK_SCATTER_STORE, 5,
+	pattern_stmt = gimple_build_call_internal (gs_info.ifn, 5,
 						   base, offset, scale, rhs,
 						   mask);
       else
-	pattern_stmt = gimple_build_call_internal (IFN_SCATTER_STORE, 4,
+	pattern_stmt = gimple_build_call_internal (gs_info.ifn, 4,
 						   base, offset, scale, rhs);
     }
   gimple_call_set_nothrow (pattern_stmt, true);
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index cc6c091..4e0b2ad 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -2510,14 +2510,6 @@ vect_check_scalar_mask (vec_info *vinfo, stmt_vec_info stmt_info,
       return false;
     }
 
-  if (TREE_CODE (*mask) != SSA_NAME)
-    {
-      if (dump_enabled_p ())
-	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-			 "mask argument is not an SSA name.\n");
-      return false;
-    }
-
   /* If the caller is not prepared for adjusting an external/constant
      SLP mask vector type fail.  */
   if (slp_node