Support -m[no-]gather -m[no-]scatter to enable/disable vectorization for all gather/scatter instructions

Rename original use_gather to use_gather_8parts, Support
-mtune-ctrl={,^}use_gather to set/clear tune features
use_gather_{2parts, 4parts, 8parts}. Support the new option -mgather
as alias of -mtune-ctrl=, use_gather, ^use_gather.

Similar for use_scatter.

gcc/ChangeLog:

	* config/i386/i386-builtins.cc
	(ix86_vectorize_builtin_gather): Adjust for use_gather_8parts.
	* config/i386/i386-options.cc (parse_mtune_ctrl_str):
	Set/Clear tune features use_{gather,scatter}_{2parts, 4parts,
	8parts} for -mtune-crtl={,^}{use_gather,use_scatter}.
	* config/i386/i386.cc (ix86_vectorize_builtin_scatter): Adjust
	for use_scatter_8parts
	* config/i386/i386.h (TARGET_USE_GATHER): Rename to ..
	(TARGET_USE_GATHER_8PARTS): .. this.
	(TARGET_USE_SCATTER): Rename to ..
	(TARGET_USE_SCATTER_8PARTS): .. this.
	* config/i386/x86-tune.def (X86_TUNE_USE_GATHER): Rename to
	(X86_TUNE_USE_GATHER_8PARTS): .. this.
	(X86_TUNE_USE_SCATTER): Rename to
	(X86_TUNE_USE_SCATTER_8PARTS): .. this.
	* config/i386/i386.opt: Add new options mgather, mscatter.

6 files changed, 56 insertions, 22 deletions

diff --git a/gcc/config/i386/i386-builtins.cc b/gcc/config/i386/i386-builtins.cc
index 356b6df..8a0b8df 100644
--- a/gcc/config/i386/i386-builtins.cc
+++ b/gcc/config/i386/i386-builtins.cc
@@ -1657,7 +1657,7 @@ ix86_vectorize_builtin_gather (const_tree mem_vectype,
 	  ? !TARGET_USE_GATHER_2PARTS
 	  : (known_eq (TYPE_VECTOR_SUBPARTS (mem_vectype), 4u)
 	     ? !TARGET_USE_GATHER_4PARTS
-	     : !TARGET_USE_GATHER)))
+	     : !TARGET_USE_GATHER_8PARTS)))
     return NULL_TREE;
 
   if ((TREE_CODE (index_type) != INTEGER_TYPE
diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
index e6ba33c..c8b56b8 100644
--- a/gcc/config/i386/i386-options.cc
+++ b/gcc/config/i386/i386-options.cc
@@ -1736,20 +1736,46 @@ parse_mtune_ctrl_str (struct gcc_options *opts, bool dump)
           curr_feature_string++;
           clear = true;
         }
-      for (i = 0; i < X86_TUNE_LAST; i++)
-        {
-          if (!strcmp (curr_feature_string, ix86_tune_feature_names[i]))
-            {
-              ix86_tune_features[i] = !clear;
-              if (dump)
-                fprintf (stderr, "Explicitly %s feature %s\n",
-                         clear ? "clear" : "set", ix86_tune_feature_names[i]);
-              break;
-            }
-        }
-      if (i == X86_TUNE_LAST)
-	error ("unknown parameter to option %<-mtune-ctrl%>: %s",
-	       clear ? curr_feature_string - 1 : curr_feature_string);
+
+      if (!strcmp (curr_feature_string, "use_gather"))
+	{
+	  ix86_tune_features[X86_TUNE_USE_GATHER_2PARTS] = !clear;
+	  ix86_tune_features[X86_TUNE_USE_GATHER_4PARTS] = !clear;
+	  ix86_tune_features[X86_TUNE_USE_GATHER_8PARTS] = !clear;
+	  if (dump)
+	    fprintf (stderr, "Explicitly %s features use_gather_2parts,"
+		     " use_gather_4parts, use_gather_8parts\n",
+		     clear ? "clear" : "set");
+
+	}
+      else if (!strcmp (curr_feature_string, "use_scatter"))
+	{
+	  ix86_tune_features[X86_TUNE_USE_SCATTER_2PARTS] = !clear;
+	  ix86_tune_features[X86_TUNE_USE_SCATTER_4PARTS] = !clear;
+	  ix86_tune_features[X86_TUNE_USE_SCATTER_8PARTS] = !clear;
+	  if (dump)
+	    fprintf (stderr, "Explicitly %s features use_scatter_2parts,"
+		     " use_scatter_4parts, use_scatter_8parts\n",
+		     clear ? "clear" : "set");
+	}
+      else
+	{
+	  for (i = 0; i < X86_TUNE_LAST; i++)
+	    {
+	      if (!strcmp (curr_feature_string, ix86_tune_feature_names[i]))
+		{
+		  ix86_tune_features[i] = !clear;
+		  if (dump)
+		    fprintf (stderr, "Explicitly %s feature %s\n",
+			     clear ? "clear" : "set", ix86_tune_feature_names[i]);
+		  break;
+		}
+	    }
+
+	  if (i == X86_TUNE_LAST)
+	    error ("unknown parameter to option %<-mtune-ctrl%>: %s",
+		   clear ? curr_feature_string - 1 : curr_feature_string);
+	}
       curr_feature_string = next_feature_string;
     }
   while (curr_feature_string);
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index d592ece..cd49fb9 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -19193,7 +19193,7 @@ ix86_vectorize_builtin_scatter (const_tree vectype,
       ? !TARGET_USE_SCATTER_2PARTS
       : (known_eq (TYPE_VECTOR_SUBPARTS (vectype), 4u)
 	 ? !TARGET_USE_SCATTER_4PARTS
-	 : !TARGET_USE_SCATTER))
+	 : !TARGET_USE_SCATTER_8PARTS))
     return NULL_TREE;
 
   if ((TREE_CODE (index_type) != INTEGER_TYPE
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index ef342fc..f7330e8 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -403,10 +403,10 @@ extern unsigned char ix86_tune_features[X86_TUNE_LAST];
 	ix86_tune_features[X86_TUNE_USE_GATHER_4PARTS]
 #define TARGET_USE_SCATTER_4PARTS \
 	ix86_tune_features[X86_TUNE_USE_SCATTER_4PARTS]
-#define TARGET_USE_GATHER \
-	ix86_tune_features[X86_TUNE_USE_GATHER]
-#define TARGET_USE_SCATTER \
-	ix86_tune_features[X86_TUNE_USE_SCATTER]
+#define TARGET_USE_GATHER_8PARTS \
+	ix86_tune_features[X86_TUNE_USE_GATHER_8PARTS]
+#define TARGET_USE_SCATTER_8PARTS \
+	ix86_tune_features[X86_TUNE_USE_SCATTER_8PARTS]
 #define TARGET_FUSE_CMP_AND_BRANCH_32 \
 	ix86_tune_features[X86_TUNE_FUSE_CMP_AND_BRANCH_32]
 #define TARGET_FUSE_CMP_AND_BRANCH_64 \
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index 8a43187..78b4993 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -1302,3 +1302,11 @@ msm4
 Target Mask(ISA2_SM4) Var(ix86_isa_flags2) Save
 Support MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, AVX and
 SM4 built-in functions and code generation.
+
+mgather
+Target Alias(mtune-ctrl=, use_gather, ^use_gather)
+Enable vectorization for gather instruction.
+
+mscatter
+Target Alias(mtune-ctrl=, use_scatter, ^use_scatter)
+Enable vectorization for scatter instruction.
diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
index 22d26bb..735d663 100644
--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -511,13 +511,13 @@ DEF_TUNE (X86_TUNE_USE_SCATTER_4PARTS, "use_scatter_4parts",
 
 /* X86_TUNE_USE_GATHER: Use gather instructions for vectors with 8 or more
    elements.  */
-DEF_TUNE (X86_TUNE_USE_GATHER, "use_gather",
+DEF_TUNE (X86_TUNE_USE_GATHER_8PARTS, "use_gather_8parts",
 	  ~(m_ZNVER1 | m_ZNVER2 | m_ZNVER4 | m_ALDERLAKE | m_ARROWLAKE
 	    | m_CORE_ATOM | m_GENERIC | m_GDS))
 
 /* X86_TUNE_USE_SCATTER: Use scater instructions for vectors with 8 or more
    elements.  */
-DEF_TUNE (X86_TUNE_USE_SCATTER, "use_scatter",
+DEF_TUNE (X86_TUNE_USE_SCATTER_8PARTS, "use_scatter_8parts",
 	  ~(m_ZNVER4))
 
 /* X86_TUNE_AVOID_128FMA_CHAINS: Avoid creating loops with tight 128bit or