RFA: Replace LAST_INSN_CODE with NUM_INSN_CODES

[Richard Sandiford <richard.sandiford@arm.com>]

Claudiu reported that I'd botched the definition of LAST_INSN_CODE
in my recent patches to reduce the size of insn_data.  I'd defined
it as the last valid insn code, whereas it's supposed to be the
last valid code +1.

This patch replaces LAST_INSN_CODE with a separate NUM_INSN_CODES
count, outside the enum.

Tested on x86_64-linux-gnu and aarch64-linux-gnu.  OK to install?

Thanks,
Richard

gcc/
	* gencodes.c (main): Replace LAST_INSN_CODE with NUM_INSN_CODES.
	* lra.c (insn_code_data): Update accordingly.
	(finish_insn_code_data_once, get_static_insn_data): Likewise.
	* recog.h (target_recog): Likewise.
	(preprocess_insn_constraints): Change parameter to unsigned int.
	* recog.c (preprocess_insn_constraints): Likewise.
	(recog_init): Replace LAST_INSN_CODE with NUM_INSN_CODES.
	* tree-vect-stmts.c (vectorizable_operation): Simplify.

diff --git a/gcc/gencodes.c b/gcc/gencodes.c
index c747891..0635507 100644
--- a/gcc/gencodes.c
+++ b/gcc/gencodes.c
@@ -83,10 +83,10 @@ enum insn_code {\n\
 	break;
     }
 
-  printf ("  LAST_INSN_CODE = %d\n\
-};\n\
+  printf ("};\n\
 \n\
-#endif /* GCC_INSN_CODES_H */\n", get_num_insn_codes () - 1);
+const unsigned int NUM_INSN_CODES = %d;\n\
+#endif /* GCC_INSN_CODES_H */\n", get_num_insn_codes ());
 
   if (ferror (stdout) || fflush (stdout) || fclose (stdout))
     return FATAL_EXIT_CODE;
diff --git a/gcc/lra.c b/gcc/lra.c
index 8ced164..a836cab 100644
--- a/gcc/lra.c
+++ b/gcc/lra.c
@@ -585,7 +585,7 @@ finish_insn_regs (void)
 
 /* Map INSN_CODE -> the static insn data.  This info is valid during
    all translation unit.  */
-struct lra_static_insn_data *insn_code_data[LAST_INSN_CODE];
+struct lra_static_insn_data *insn_code_data[NUM_INSN_CODES];
 
 /* Debug insns are represented as a special insn with one input
    operand which is RTL expression in var_location.  */
@@ -631,9 +631,7 @@ init_insn_code_data_once (void)
 static void
 finish_insn_code_data_once (void)
 {
-  int i;
-
-  for (i = 0; i < LAST_INSN_CODE; i++)
+  for (unsigned int i = 0; i < NUM_INSN_CODES; i++)
     {
       if (insn_code_data[i] != NULL)
 	free (insn_code_data[i]);
@@ -650,7 +648,7 @@ get_static_insn_data (int icode, int nop, int ndup, int nalt)
   struct lra_static_insn_data *data;
   size_t n_bytes;
 
-  lra_assert (icode < LAST_INSN_CODE);
+  lra_assert (icode < (int) NUM_INSN_CODES);
   if (icode >= 0 && (data = insn_code_data[icode]) != NULL)
     return data;
   lra_assert (nop >= 0 && ndup >= 0 && nalt >= 0);
diff --git a/gcc/recog.c b/gcc/recog.c
index 352aec2..c032424 100644
--- a/gcc/recog.c
+++ b/gcc/recog.c
@@ -2441,9 +2441,9 @@ preprocess_constraints (int n_operands, int n_alternatives,
    instruction ICODE.  */
 
 const operand_alternative *
-preprocess_insn_constraints (int icode)
+preprocess_insn_constraints (unsigned int icode)
 {
-  gcc_checking_assert (IN_RANGE (icode, 0, LAST_INSN_CODE));
+  gcc_checking_assert (IN_RANGE (icode, 0, NUM_INSN_CODES - 1));
   if (this_target_recog->x_op_alt[icode])
     return this_target_recog->x_op_alt[icode];
 
@@ -4118,7 +4118,7 @@ recog_init ()
     }
   memset (this_target_recog->x_bool_attr_masks, 0,
 	  sizeof (this_target_recog->x_bool_attr_masks));
-  for (int i = 0; i < LAST_INSN_CODE; ++i)
+  for (unsigned int i = 0; i < NUM_INSN_CODES; ++i)
     if (this_target_recog->x_op_alt[i])
       {
 	free (this_target_recog->x_op_alt[i]);
diff --git a/gcc/recog.h b/gcc/recog.h
index ce931eb..327d6c0 100644
--- a/gcc/recog.h
+++ b/gcc/recog.h
@@ -137,7 +137,7 @@ extern void extract_constrain_insn_cached (rtx_insn *);
 extern void extract_insn_cached (rtx_insn *);
 extern void preprocess_constraints (int, int, const char **,
 				    operand_alternative *);
-extern const operand_alternative *preprocess_insn_constraints (int);
+extern const operand_alternative *preprocess_insn_constraints (unsigned int);
 extern void preprocess_constraints (rtx_insn *);
 extern rtx_insn *peep2_next_insn (int);
 extern int peep2_regno_dead_p (int, int);
@@ -393,8 +393,8 @@ enum bool_attr {
 /* Target-dependent globals.  */
 struct target_recog {
   bool x_initialized;
-  alternative_mask x_bool_attr_masks[LAST_INSN_CODE][BA_LAST + 1];
-  operand_alternative *x_op_alt[LAST_INSN_CODE];
+  alternative_mask x_bool_attr_masks[NUM_INSN_CODES][BA_LAST + 1];
+  operand_alternative *x_op_alt[NUM_INSN_CODES];
 };
 
 extern struct target_recog default_target_recog;
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 2ddd434..f87c066 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -4719,7 +4719,7 @@ vectorizable_operation (gimple stmt, gimple_stmt_iterator *gsi,
   tree new_temp;
   int op_type;
   optab optab;
-  int icode;
+  bool target_support_p;
   tree def;
   gimple def_stmt;
   enum vect_def_type dt[3]
@@ -4870,12 +4870,7 @@ vectorizable_operation (gimple stmt, gimple_stmt_iterator *gsi,
 
   vec_mode = TYPE_MODE (vectype);
   if (code == MULT_HIGHPART_EXPR)
-    {
-      if (can_mult_highpart_p (vec_mode, TYPE_UNSIGNED (vectype)))
-	icode = LAST_INSN_CODE;
-      else
-	icode = CODE_FOR_nothing;
-    }
+    target_support_p = can_mult_highpart_p (vec_mode, TYPE_UNSIGNED (vectype));
   else
     {
       optab = optab_for_tree_code (code, vectype, optab_default);
@@ -4886,10 +4881,11 @@ vectorizable_operation (gimple stmt, gimple_stmt_iterator *gsi,
                              "no optab.\n");
 	  return false;
 	}
-      icode = (int) optab_handler (optab, vec_mode);
+      target_support_p = (optab_handler (optab, vec_mode)
+			  != CODE_FOR_nothing);
     }
 
-  if (icode == CODE_FOR_nothing)
+  if (!target_support_p)
     {
       if (dump_enabled_p ())
 	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,