[C++ PATCH] overloaded operator fns [6/N]

https://gcc.gnu.org/ml/gcc-patches/2017-11/msg00018.html
	* cp-tree.h (IDENTIFIER_CP_INDEX): Define.
	(enum ovl_op_flags): Add OVL_OP_FLAG_AMBIARY.
	(enum ovl_op_code): New.
	(struct ovl_op_info): Add ovl_op_code field.
	(ovl_op_info): Size by OVL_OP_MAX.
	(ovl_op_mapping, ovl_op_alternate): Declare.
	(OVL_OP_INFO): Adjust for mapping array.
	(IDENTIFIER_OVL_OP_INFO): New.
	* decl.c (ambi_op_p, unary_op_p): Delete.
	(grok_op_properties): Use IDENTIFIER_OVL_OP_INFO and
	ovl_op_alternate.
	* lex.c (ovl_op_info): Adjust and static initialize.
	(ovl_op_mappings, ovl_op_alternate): Define.
	(init_operators): Iterate over ovl_op_info array and init mappings
	& alternate arrays.
	* mangle.c (write_unqualified_id): Use IDENTIFIER_OVL_OP_INFO.
	* operators.def (DEF_OPERATOR): Remove KIND parm.
	(DEF_SIMPLE_OPERATOR): Delete.
	(OPERATOR_TRANSITION): Expand if defined.

From-SVN: r254310

gcc/cp/ChangeLog

+2017-11-01  Nathan Sidwell  <nathan@acm.org>
+
+	* cp-tree.h (IDENTIFIER_CP_INDEX): Define.
+	(enum ovl_op_flags): Add OVL_OP_FLAG_AMBIARY.
+	(enum ovl_op_code): New.
+	(struct ovl_op_info): Add ovl_op_code field.
+	(ovl_op_info): Size by OVL_OP_MAX.
+	(ovl_op_mapping, ovl_op_alternate): Declare.
+	(OVL_OP_INFO): Adjust for mapping array.
+	(IDENTIFIER_OVL_OP_INFO): New.
+	* decl.c (ambi_op_p, unary_op_p): Delete.
+	(grok_op_properties): Use IDENTIFIER_OVL_OP_INFO and
+	ovl_op_alternate.
+	* lex.c (ovl_op_info): Adjust and static initialize.
+	(ovl_op_mappings, ovl_op_alternate): Define.
+	(init_operators): Iterate over ovl_op_info array and init mappings
+	& alternate arrays.
+	* mangle.c (write_unqualified_id): Use IDENTIFIER_OVL_OP_INFO.
+	* operators.def (DEF_OPERATOR): Remove KIND parm.
+	(DEF_SIMPLE_OPERATOR): Delete.
+	(OPERATOR_TRANSITION): Expand if defined.
+
 2017-10-31  David Malcolm  <dmalcolm@redhat.com>
 
 	* pt.c (listify): Use %< and %> for description of #include.

gcc/cp/cp-tree.h

@@ -1072,6 +1072,11 @@ enum cp_identifier_kind {
    & IDENTIFIER_KIND_BIT_1 (NODE)		\
    & IDENTIFIER_KIND_BIT_0 (NODE))
 
+/* Access a C++-specific index for identifier NODE.
+   Used to optimize operator mappings etc.  */
+#define IDENTIFIER_CP_INDEX(NODE)		\
+  (IDENTIFIER_NODE_CHECK(NODE)->base.u.bits.address_space)
+
 /* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is read-only.  */
 #define C_TYPE_FIELDS_READONLY(TYPE) \
   (LANG_TYPE_CLASS_CHECK (TYPE)->fields_readonly)
@@ -5477,12 +5482,25 @@ extern void init_reswords (void);
 /* Various flags for the overloaded operator information.  */
 enum ovl_op_flags
   {
-    OVL_OP_FLAG_NONE = 0,
-    OVL_OP_FLAG_UNARY = 1,
-    OVL_OP_FLAG_BINARY = 2,
-    OVL_OP_FLAG_ALLOC = 4,  	/* operator new or delete  */
-    OVL_OP_FLAG_DELETE = 1,	/* operator delete  */
-    OVL_OP_FLAG_VEC = 2		/* vector new or delete  */
+    OVL_OP_FLAG_NONE = 0,	/* Don't care.  */
+    OVL_OP_FLAG_UNARY = 1,	/* Is unary.  */
+    OVL_OP_FLAG_BINARY = 2,	/* Is binary.  */
+    OVL_OP_FLAG_AMBIARY = 3,	/* May be unary or binary.  */
+    OVL_OP_FLAG_ALLOC = 4,  	/* operator new or delete.  */
+    OVL_OP_FLAG_DELETE = 1,	/* operator delete.  */
+    OVL_OP_FLAG_VEC = 2		/* vector new or delete.  */
+  };
+
+/* Compressed operator codes.  Order is determined by operators.def
+   and does not match that of tree_codes.  */
+enum ovl_op_code
+  {
+    OVL_OP_ERROR_MARK,
+    OVL_OP_NOP_EXPR,
+#define DEF_OPERATOR(NAME, CODE, MANGLING, FLAGS) OVL_OP_##CODE,
+#define DEF_ASSN_OPERATOR(NAME, CODE, MANGLING) /* NOTHING */
+#include "operators.def"
+    OVL_OP_MAX
   };
 
 struct GTY(()) ovl_op_info_t {
@@ -5492,19 +5510,29 @@ struct GTY(()) ovl_op_info_t {
   const char *name;
   /* The mangled name of the operator.  */
   const char *mangled_name;
-  /* The tree code.  */
+  /* The (regular) tree code.  */
   enum tree_code tree_code : 16;
+  /* The (compressed) operator code.  */
+  enum ovl_op_code ovl_op_code : 8;
   /* The ovl_op_flags of the operator */
   unsigned flags : 8;
 };
 
-/* Overloaded operator info indexed by ass_op_p & tree_code.  */
-extern GTY(()) ovl_op_info_t ovl_op_info[2][MAX_TREE_CODES];
+/* Overloaded operator info indexed by ass_op_p & ovl_op_code.  */
+extern GTY(()) ovl_op_info_t ovl_op_info[2][OVL_OP_MAX];
+/* Mapping from tree_codes to ovl_op_codes.  */
+extern GTY(()) unsigned char ovl_op_mapping[MAX_TREE_CODES];
+/* Mapping for ambi-ary operators from the binary to the unary.  */
+extern GTY(()) unsigned char ovl_op_alternate[OVL_OP_MAX];
 
 /* Given an ass_op_p boolean and a tree code, return a pointer to its
    overloaded operator info.  */
 #define OVL_OP_INFO(IS_ASS_P, TREE_CODE)			\
-  (&ovl_op_info[(IS_ASS_P) != 0][(TREE_CODE)])
+  (&ovl_op_info[(IS_ASS_P) != 0][ovl_op_mapping[(TREE_CODE)]])
+/* Overloaded operator info for an identifier for which
+   IDENTIFIER_ANY_OP_P is true.  */
+#define IDENTIFIER_OVL_OP_INFO(NODE) \
+  (&ovl_op_info[IDENTIFIER_ASSIGN_OP_P (NODE)][IDENTIFIER_CP_INDEX (NODE)])
 
 /* A type-qualifier, or bitmask therefore, using the TYPE_QUAL
    constants.  */

gcc/cp/decl.c

@@ -65,8 +65,6 @@ static const char *redeclaration_error_message (tree, tree);
 
 static int decl_jump_unsafe (tree);
 static void require_complete_types_for_parms (tree);
-static bool ambi_op_p (enum tree_code);
-static bool unary_op_p (enum tree_code);
 static void push_local_name (tree);
 static tree grok_reference_init (tree, tree, tree, int);
 static tree grokvardecl (tree, tree, tree, const cp_decl_specifier_seq *,
@@ -12874,30 +12872,6 @@ grok_ctor_properties (const_tree ctype, const_tree decl)
   return true;
 }
 
-/* An operator with this code is unary, but can also be binary.  */
-
-static bool
-ambi_op_p (enum tree_code code)
-{
-  return (code == INDIRECT_REF
-	  || code == ADDR_EXPR
-	  || code == UNARY_PLUS_EXPR
-	  || code == NEGATE_EXPR
-	  || code == PREINCREMENT_EXPR
-	  || code == PREDECREMENT_EXPR);
-}
-
-/* An operator with this name can only be unary.  */
-
-static bool
-unary_op_p (enum tree_code code)
-{
-  return (code == TRUTH_NOT_EXPR
-	  || code == BIT_NOT_EXPR
-	  || code == COMPONENT_REF
-	  || code == TYPE_EXPR);
-}
-
 /* DECL is a declaration for an overloaded or conversion operator.  If
    COMPLAIN is true, errors are issued for invalid declarations.  */
 
@@ -12905,15 +12879,15 @@ bool
 grok_op_properties (tree decl, bool complain)
 {
   tree argtypes = TYPE_ARG_TYPES (TREE_TYPE (decl));
-  int methodp = (TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE);
+  bool methodp = TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE;
   tree name = DECL_NAME (decl);
 
   tree class_type = DECL_CONTEXT (decl);
   if (class_type && !CLASS_TYPE_P (class_type))
     class_type = NULL_TREE;
 
-  tree_code operator_code = ERROR_MARK;
-  unsigned op_flags = OVL_OP_FLAG_NONE;
+  tree_code operator_code;
+  unsigned op_flags;
   if (IDENTIFIER_CONV_OP_P (name))
     {
       /* Conversion operators are TYPE_EXPR for the purposes of this
@@ -12923,21 +12897,11 @@ grok_op_properties (tree decl, bool complain)
     }
   else
     {
-      /* It'd be nice to hang something else of the identifier to
-	 find CODE more directly.  */
-      bool assign_op = IDENTIFIER_ASSIGN_OP_P (name);
-      const ovl_op_info_t *ovl_op = OVL_OP_INFO (assign_op, 0);
-      if (false)
-	;
-#define DEF_OPERATOR(NAME, CODE, MANGLING, FLAGS, KIND)		\
-      else if (ovl_op[CODE].identifier == name)			\
-	operator_code = (CODE);
-#include "operators.def"
-#undef DEF_OPERATOR
-      else
-	gcc_unreachable ();
-      gcc_assert (operator_code != ERROR_MARK);
-      op_flags = ovl_op[operator_code].flags;
+      const ovl_op_info_t *ovl_op = IDENTIFIER_OVL_OP_INFO (name);
+
+      operator_code = ovl_op->tree_code;
+      op_flags = ovl_op->flags;
+      gcc_checking_assert (operator_code != ERROR_MARK);
       DECL_OVERLOADED_OPERATOR_CODE (decl) = operator_code;
     }
 
@@ -13071,70 +13035,43 @@ grok_op_properties (tree decl, bool complain)
     }
 
   /* Verify correct number of arguments.  */
-  if (ambi_op_p (operator_code))
+  switch (op_flags)
     {
+    case OVL_OP_FLAG_AMBIARY:
       if (arity == 1)
-	/* We pick the one-argument operator codes by default, so
-	   we don't have to change anything.  */
-	;
-      else if (arity == 2)
 	{
-	  /* If we thought this was a unary operator, we now know
-	     it to be a binary operator.  */
-	  switch (operator_code)
-	    {
-	    case INDIRECT_REF:
-	      operator_code = MULT_EXPR;
-	      break;
-
-	    case ADDR_EXPR:
-	      operator_code = BIT_AND_EXPR;
-	      break;
-
-	    case UNARY_PLUS_EXPR:
-	      operator_code = PLUS_EXPR;
-	      break;
-
-	    case NEGATE_EXPR:
-	      operator_code = MINUS_EXPR;
-	      break;
-
-	    case PREINCREMENT_EXPR:
-	      operator_code = POSTINCREMENT_EXPR;
-	      break;
-
-	    case PREDECREMENT_EXPR:
-	      operator_code = POSTDECREMENT_EXPR;
-	      break;
-
-	    default:
-	      gcc_unreachable ();
-	    }
-
+	  /* We have a unary instance of an ambi-ary op.  Remap to the
+	     unary one.  */
+	  unsigned alt = ovl_op_alternate[ovl_op_mapping [operator_code]];
+	  const ovl_op_info_t *ovl_op = &ovl_op_info[false][alt];
+	  gcc_checking_assert (ovl_op->flags == OVL_OP_FLAG_UNARY);
+	  operator_code = ovl_op->tree_code;
 	  DECL_OVERLOADED_OPERATOR_CODE (decl) = operator_code;
-
-	  if ((operator_code == POSTINCREMENT_EXPR
-	       || operator_code == POSTDECREMENT_EXPR)
-	      && ! processing_template_decl
-	      && ! same_type_p (TREE_VALUE (TREE_CHAIN (argtypes)), integer_type_node))
-	    {
-	      error (methodp
-		 ? G_("postfix %qD must have %<int%> as its argument")
-		 : G_("postfix %qD must have %<int%> as its second argument"),
-		 decl);
-	      return false;
-	    }
 	}
-      else
+      else if (arity != 2)
 	{
+	  /* This was an ambiguous operator but is invalid. */
 	  error (methodp
 		 ? G_("%qD must have either zero or one argument")
 		 : G_("%qD must have either one or two arguments"), decl);
 	  return false;
 	}
-    }
-  else if (unary_op_p (operator_code))
-    {
+      else if ((operator_code == POSTINCREMENT_EXPR
+		|| operator_code == POSTDECREMENT_EXPR)
+	       && ! processing_template_decl
+	       /* x++ and x--'s second argument must be an int.  */
+	       && ! same_type_p (TREE_VALUE (TREE_CHAIN (argtypes)),
+				 integer_type_node))
+	{
+	  error (methodp
+		 ? G_("postfix %qD must have %<int%> as its argument")
+		 : G_("postfix %qD must have %<int%> as its second argument"),
+		 decl);
+	  return false;
+	}
+      break;
+
+    case OVL_OP_FLAG_UNARY:
       if (arity != 1)
 	{
 	  error (methodp
@@ -13142,9 +13079,9 @@ grok_op_properties (tree decl, bool complain)
 		 : G_("%qD must have exactly one argument"), decl);
 	  return false;
 	}
-    }
-  else
-    {
+      break;
+
+    case OVL_OP_FLAG_BINARY:
       if (arity != 2)
 	{
 	  error (methodp
@@ -13152,8 +13089,12 @@ grok_op_properties (tree decl, bool complain)
 		 : G_("%qD must have exactly two arguments"), decl);
 	  return false;
 	}
+      break;
+
+    default:
+      gcc_unreachable ();
     }
-  
+
   /* There can be no default arguments.  */
   for (tree arg = argtypes; arg != void_list_node; arg = TREE_CHAIN (arg))
     if (TREE_PURPOSE (arg))

gcc/cp/lex.c

@@ -77,7 +77,20 @@ cxx_finish (void)
   c_common_finish ();
 }
 
-ovl_op_info_t ovl_op_info[2][MAX_TREE_CODES];
+ovl_op_info_t ovl_op_info[2][OVL_OP_MAX] = 
+  {
+    {
+      {NULL_TREE, NULL, NULL, ERROR_MARK, OVL_OP_ERROR_MARK, 0},
+      {NULL_TREE, NULL, NULL, NOP_EXPR, OVL_OP_NOP_EXPR, 0},
+#define DEF_OPERATOR(NAME, CODE, MANGLING, FLAGS) \
+      {NULL_TREE, NAME, MANGLING, CODE, OVL_OP_##CODE, FLAGS},
+#define OPERATOR_TRANSITION }, {			\
+      {NULL_TREE, NULL, NULL, ERROR_MARK, OVL_OP_ERROR_MARK, 0},
+#include "operators.def"
+    }
+  };
+unsigned char ovl_op_mapping[MAX_TREE_CODES];
+unsigned char ovl_op_alternate[OVL_OP_MAX];
 
 /* Get the name of the kind of identifier T.  */
 
@@ -129,26 +142,77 @@ set_operator_ident (ovl_op_info_t *ptr)
   return ident;
 }
 
+/* Initialize data structures that keep track of operator names.  */
+
 static void
 init_operators (void)
 {
-  tree identifier;
-  ovl_op_info_t *oni;
-
-#define DEF_OPERATOR(NAME, CODE, MANGLING, FLAGS, KIND)			\
-  oni = OVL_OP_INFO (KIND == cik_assign_op, CODE);			\
-  oni->name = NAME;							\
-  oni->mangled_name = MANGLING;						\
-  oni->tree_code = CODE;						\
-  oni->flags = FLAGS;							\
-  if (NAME) {								\
-    identifier = set_operator_ident (oni);				\
-    if (KIND != cik_simple_op || !IDENTIFIER_ANY_OP_P (identifier))	\
-      set_identifier_kind (identifier, KIND);				\
-  }
+  /* We rely on both these being zero.  */
+  gcc_checking_assert (!OVL_OP_ERROR_MARK && !ERROR_MARK);
 
-#include "operators.def"
-#undef DEF_OPERATOR
+  /* This loop iterates backwards because we need to move the
+     assignment operators down to their correct slots.  I.e. morally
+     equivalent to an overlapping memmove where dest > src.  Slot
+     zero is for error_mark, so hae no operator. */
+  for (unsigned ix = OVL_OP_MAX; --ix;)
+    {
+      ovl_op_info_t *op_ptr = &ovl_op_info[false][ix];
+
+      if (op_ptr->name)
+	{
+	  /* Make sure it fits in lang_decl_fn::operator_code. */
+	  gcc_checking_assert (op_ptr->ovl_op_code < (1 << 6));
+	  tree ident = set_operator_ident (op_ptr);
+	  if (unsigned index = IDENTIFIER_CP_INDEX (ident))
+	    {
+	      ovl_op_info_t *bin_ptr = &ovl_op_info[false][index];
+
+	      /* They should only differ in unary/binary ness.  */
+	      gcc_checking_assert ((op_ptr->flags ^ bin_ptr->flags)
+				   == OVL_OP_FLAG_AMBIARY);
+	      bin_ptr->flags |= op_ptr->flags;
+	      ovl_op_alternate[index] = ix;
+	    }
+	  else
+	    {
+	      IDENTIFIER_CP_INDEX (ident) = ix;
+	      set_identifier_kind (ident,
+				   op_ptr->flags & OVL_OP_FLAG_ALLOC
+				   ? cik_newdel_op : cik_simple_op);
+	    }
+	}
+      if (op_ptr->tree_code)
+	{
+	  gcc_checking_assert (op_ptr->ovl_op_code == ix
+			       && !ovl_op_mapping[op_ptr->tree_code]);
+	  ovl_op_mapping[op_ptr->tree_code] = op_ptr->ovl_op_code;
+	}
+
+      ovl_op_info_t *as_ptr = &ovl_op_info[true][ix];
+      if (as_ptr->name)
+	{
+	  /* These will be placed at the start of the array, move to
+	     the correct slot and initialize.  */
+	  if (as_ptr->ovl_op_code != ix)
+	    {
+	      ovl_op_info_t *dst_ptr = &ovl_op_info[true][as_ptr->ovl_op_code];
+	      gcc_assert (as_ptr->ovl_op_code > ix && !dst_ptr->tree_code);
+	      memcpy (dst_ptr, as_ptr, sizeof (*dst_ptr));
+	      memset (as_ptr, 0, sizeof (*as_ptr));
+	      as_ptr = dst_ptr;
+	    }
+
+	  tree ident = set_operator_ident (as_ptr);
+	  gcc_checking_assert (!IDENTIFIER_CP_INDEX (ident));
+	  IDENTIFIER_CP_INDEX (ident) = as_ptr->ovl_op_code;
+	  set_identifier_kind (ident, cik_assign_op);
+
+	  gcc_checking_assert (!ovl_op_mapping[as_ptr->tree_code]
+			       || (ovl_op_mapping[as_ptr->tree_code]
+				   == as_ptr->ovl_op_code));
+	  ovl_op_mapping[as_ptr->tree_code] = as_ptr->ovl_op_code;
+	}
+    }
 }
 
 /* Initialize the reserved words.  */

gcc/cp/mangle.c

@@ -1265,30 +1265,8 @@ write_unqualified_id (tree identifier)
     write_conversion_operator_name (TREE_TYPE (identifier));
   else if (IDENTIFIER_ANY_OP_P (identifier))
     {
-      const char *mangled_name = NULL;
-      bool assop = IDENTIFIER_ASSIGN_OP_P (identifier);
-
-      /* Unfortunately, there is no easy way to go from the
-	 name of the operator back to the corresponding tree
-	 code.  */
-      for (unsigned i = 0; i < MAX_TREE_CODES; ++i)
-	{
-	  const ovl_op_info_t *ovl_op = OVL_OP_INFO (assop, i);
-
-	  if (ovl_op->identifier == identifier)
-	    {
-	      /* The ABI says that we prefer binary operator
-		 names to unary operator names.  */
-	      if (ovl_op->flags == OVL_OP_FLAG_BINARY)
-		{
-		  mangled_name = ovl_op->mangled_name;
-		  break;
-		}
-	      else if (!mangled_name)
-		mangled_name = ovl_op->mangled_name;
-	    }
-	}
-      write_string (mangled_name);
+      const ovl_op_info_t *ovl_op = IDENTIFIER_OVL_OP_INFO (identifier);
+      write_string (ovl_op->mangled_name);
     }
   else if (UDLIT_OPER_P (identifier))
     write_literal_operator_name (identifier);