rtl.texi (SYMBOL_REF_CONSTANT, [...]): Document.

* doc/rtl.texi (SYMBOL_REF_CONSTANT, SYMBOL_REF_DATA): Document.
	* gengtype.c (adjust_field_rtx_def): Garbage-collect field 2 of
	a SYMBOL_REF as either a tree or a constant_descriptor_rtx,
	depending on the value of CONSTANT_POOL_ADDRESS_P.
	* optabs.c (init_one_libfunc): Nullify SYMBOL_REF_DATA rather than
	SYMBOL_REF_DECL.
	* varasm.c (make_decl_rtl, build_constant_desc): Set SYMBOL_REF_DATA
	rather than SYMBOL_REF_DECL.
	(rtx_constant_pool): Remove const_rtx_sym_htab.
	(const_desc_rtx_sym_hash, const_desc_rtx_sym_eq): Delete.
	(init_varasm_status): Don't initialize const_rtx_sym_htab.
	(force_const_mem): Point SYMBOL_REF_DATA to the constant pool entry.
	Remove handling of const_rtx_sym_htab.
	(find_pool_constant): Delete.
	(get_pool_constant, get_pool_constant_mark): Use SYMBOL_REF_CONSTANT
	rather than find_pool_constant.
	(get_pool_constant_for_function): Delete.
	(get_pool_mode, mark_constant): Use SYMBOL_REF_CONSTANT rather than
	find_pool_constant. 
	* rtl.h (rtunion_def): Add rt_constant and rt_ptr fields.
	(X0CONSTANT, X0PTR, SYMBOL_REF_DATA): New macros.
	(SYMBOL_REF_DECL): Return NULL if CONSTANT_POOL_ADDRESS_P.
	(SYMBOL_REF_CONSTANT): New macro.
	(get_pool_constant_for_function): Delete.
	* config/i386/winnt.c (i386_pe_mark_dllexport): Set SYMBOL_REF_DATA
	rather than SYMBOL_REF_DECL.
	(i386_pe_mark_dllimport): Likewise.
	* config/rs6000/rs6000.c (rs6000_emit_move): Copy SYMBOL_REF_DATA
	rather than SYMBOL_REF_DECL.
	* config/darwin.c (machopic_indirect_data_reference): Likewise.
	(machopic_indirect_call_target): Likewise.

From-SVN: r110210

gcc/config/darwin.c

@@ -559,7 +559,7 @@ machopic_indirect_data_reference (rtx orig, rtx reg)
 		 (Pmode,
 		  machopic_indirection_name (orig, /*stub_p=*/false)));
 
-      SYMBOL_REF_DECL (ptr_ref) = SYMBOL_REF_DECL (orig);
+      SYMBOL_REF_DATA (ptr_ref) = SYMBOL_REF_DATA (orig);
 
       ptr_ref = gen_const_mem (Pmode, ptr_ref);
       machopic_define_symbol (ptr_ref);
@@ -642,10 +642,9 @@ machopic_indirect_call_target (rtx target)
       const char *stub_name = machopic_indirection_name (sym_ref,
 							 /*stub_p=*/true);
       enum machine_mode mode = GET_MODE (sym_ref);
-      tree decl = SYMBOL_REF_DECL (sym_ref);
 
       XEXP (target, 0) = gen_rtx_SYMBOL_REF (mode, stub_name);
-      SYMBOL_REF_DECL (XEXP (target, 0)) = decl;
+      SYMBOL_REF_DATA (XEXP (target, 0)) = SYMBOL_REF_DATA (sym_ref);
       MEM_READONLY_P (target) = 1;
       MEM_NOTRAP_P (target) = 1;
     }

gcc/config/i386/winnt.c

@@ -229,7 +229,7 @@ i386_pe_mark_dllexport (tree decl)
   idp = get_identifier (newname);
 
   symref = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));
-  SYMBOL_REF_DECL (symref) = decl;
+  SYMBOL_REF_DATA (symref) = decl;
   XEXP (DECL_RTL (decl), 0) = symref;
 }
 
@@ -274,7 +274,7 @@ i386_pe_mark_dllimport (tree decl)
   idp = get_identifier (newname);
 
   symref = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));
-  SYMBOL_REF_DECL (symref) = decl;
+  SYMBOL_REF_DATA (symref) = decl;
   newrtl = gen_rtx_MEM (Pmode,symref);
   XEXP (DECL_RTL (decl), 0) = newrtl;
 

gcc/config/rs6000/rs6000.c

@@ -4002,7 +4002,7 @@ rs6000_emit_move (rtx dest, rtx source, enum machine_mode mode)
 		= CONSTANT_POOL_ADDRESS_P (operands[1]);
 	      SYMBOL_REF_FLAGS (new_ref) = SYMBOL_REF_FLAGS (operands[1]);
 	      SYMBOL_REF_USED (new_ref) = SYMBOL_REF_USED (operands[1]);
-	      SYMBOL_REF_DECL (new_ref) = SYMBOL_REF_DECL (operands[1]);
+	      SYMBOL_REF_DATA (new_ref) = SYMBOL_REF_DATA (operands[1]);
 	      operands[1] = new_ref;
 	    }
 

gcc/doc/rtl.texi

@@ -455,6 +455,16 @@ that is, some sort of constant.  In this case, the @code{symbol_ref}
 is an entry in the per-file constant pool; again, there is no associated
 front end symbol table entry.
 
+@findex SYMBOL_REF_CONSTANT
+@item SYMBOL_REF_CONSTANT (@var{x})
+If @samp{CONSTANT_POOL_ADDRESS_P (@var{x})} is true, this is the constant
+pool entry for @var{x}.  It is null otherwise.
+
+@findex SYMBOL_REF_DATA
+@item SYMBOL_REF_DATA (@var{x})
+A @samp{void *} pointer used to store @code{SYMBOL_REF_DECL} or
+@code{SYMBOL_REF_CONSTANT}.
+
 @findex SYMBOL_REF_FLAGS
 @item SYMBOL_REF_FLAGS (@var{x})
 In a @code{symbol_ref}, this is used to communicate various predicates

gcc/gengtype.c

@@ -454,7 +454,7 @@ adjust_field_rtx_def (type_p t, options_p ARG_UNUSED (opt))
   options_p nodot;
   int i;
   type_p rtx_tp, rtvec_tp, tree_tp, mem_attrs_tp, note_union_tp, scalar_tp;
-  type_p bitmap_tp, basic_block_tp, reg_attrs_tp;
+  type_p bitmap_tp, basic_block_tp, reg_attrs_tp, constant_tp, symbol_union_tp;
 
   if (t->kind != TYPE_UNION)
     {
@@ -472,6 +472,7 @@ adjust_field_rtx_def (type_p t, options_p ARG_UNUSED (opt))
   reg_attrs_tp = create_pointer (find_structure ("reg_attrs", 0));
   bitmap_tp = create_pointer (find_structure ("bitmap_element_def", 0));
   basic_block_tp = create_pointer (find_structure ("basic_block_def", 0));
+  constant_tp = create_pointer (find_structure ("constant_descriptor_rtx", 0));
   scalar_tp = create_scalar_type ("rtunion scalar", 14);
 
   {
@@ -510,6 +511,19 @@ adjust_field_rtx_def (type_p t, options_p ARG_UNUSED (opt))
     note_union_tp = new_structure ("rtx_def_note_subunion", 1,
 				   &lexer_line, note_flds, NULL);
   }
+  /* Create a type to represent the various forms of SYMBOL_REF_DATA.  */
+  {
+    pair_p sym_flds;
+
+    sym_flds = create_field (NULL, tree_tp, "rt_tree");
+    sym_flds->opt = create_option (nodot, "default", "");
+
+    sym_flds = create_field (sym_flds, constant_tp, "rt_constant");
+    sym_flds->opt = create_option (nodot, "tag", "1");
+
+    symbol_union_tp = new_structure ("rtx_def_symbol_subunion", 1,
+				     &lexer_line, sym_flds, NULL);
+  }
   for (i = 0; i < NUM_RTX_CODE; i++)
     {
       pair_p subfields = NULL;
@@ -562,7 +576,7 @@ adjust_field_rtx_def (type_p t, options_p ARG_UNUSED (opt))
 	      else if (i == SYMBOL_REF && aindex == 1)
 		t = scalar_tp, subname = "rt_int";
 	      else if (i == SYMBOL_REF && aindex == 2)
-		t = tree_tp, subname = "rt_tree";
+		t = symbol_union_tp, subname = "";
 	      else if (i == BARRIER && aindex >= 3)
 		t = scalar_tp, subname = "rt_int";
 	      else
@@ -627,6 +641,9 @@ adjust_field_rtx_def (type_p t, options_p ARG_UNUSED (opt))
 	  if (t == note_union_tp)
 	    subfields->opt = create_option (subfields->opt, "desc",
 					    "NOTE_LINE_NUMBER (&%0)");
+	  if (t == symbol_union_tp)
+	    subfields->opt = create_option (subfields->opt, "desc",
+					    "CONSTANT_POOL_ADDRESS_P (&%0)");
 	}
 
       sname = xasprintf ("rtx_def_%s", rtx_name[i]);

gcc/optabs.c

@@ -5133,7 +5133,7 @@ init_one_libfunc (const char *name)
 
   /* Zap the nonsensical SYMBOL_REF_DECL for this.  What we're left with
      are the flags assigned by targetm.encode_section_info.  */
-  SYMBOL_REF_DECL (symbol) = 0;
+  SYMBOL_REF_DATA (symbol) = 0;
 
   return symbol;
 }

gcc/rtl.h

@@ -171,6 +171,8 @@ union rtunion_def
   struct basic_block_def *rt_bb;
   mem_attrs *rt_mem;
   reg_attrs *rt_reg;
+  struct constant_descriptor_rtx *rt_constant;
+  void *rt_ptr;
 };
 typedef union rtunion_def rtunion;
 
@@ -630,6 +632,8 @@ extern void rtl_check_failed_flag (const char *, rtx, const char *,
 #define X0CSELIB(RTX, N)   (RTL_CHECK1 (RTX, N, '0').rt_cselib)
 #define X0MEMATTR(RTX, N)  (RTL_CHECKC1 (RTX, N, MEM).rt_mem)
 #define X0REGATTR(RTX, N)  (RTL_CHECKC1 (RTX, N, REG).rt_reg)
+#define X0CONSTANT(RTX, N) (RTL_CHECK1 (RTX, N, '0').rt_constant)
+#define X0PTR(RTX, N)      (RTL_CHECK1 (RTX, N, '0').rt_ptr)
 
 /* Access a '0' field with any type.  */
 #define X0ANY(RTX, N)	   RTL_CHECK1 (RTX, N, '0')
@@ -1193,8 +1197,17 @@ do {						\
 #define SYMBOL_REF_WEAK(RTX)						\
   (RTL_FLAG_CHECK1("SYMBOL_REF_WEAK", (RTX), SYMBOL_REF)->return_val)
 
+/* A pointer attached to the SYMBOL_REF; either SYMBOL_REF_DECL or
+   SYMBOL_REF_CONSTANT.  */
+#define SYMBOL_REF_DATA(RTX) X0PTR ((RTX), 2)
+
 /* The tree (decl or constant) associated with the symbol, or null.  */
-#define SYMBOL_REF_DECL(RTX)	X0TREE ((RTX), 2)
+#define SYMBOL_REF_DECL(RTX) \
+  (CONSTANT_POOL_ADDRESS_P (RTX) ? NULL : X0TREE ((RTX), 2))
+
+/* The rtx constant pool entry for a symbol, or null.  */
+#define SYMBOL_REF_CONSTANT(RTX) \
+  (CONSTANT_POOL_ADDRESS_P (RTX) ? X0CONSTANT ((RTX), 2) : NULL)
 
 /* A set of flags on a symbol_ref that are, in some respects, redundant with
    information derivable from the tree decl associated with this symbol.
@@ -1417,7 +1430,6 @@ struct function;
 extern rtx get_pool_constant (rtx);
 extern rtx get_pool_constant_mark (rtx, bool *);
 extern enum machine_mode get_pool_mode (rtx);
-extern rtx get_pool_constant_for_function (struct function *, rtx);
 extern rtx simplify_subtraction (rtx);
 
 /* In function.c  */

gcc/varasm.c

@@ -845,7 +845,7 @@ make_decl_rtl (tree decl)
 
   x = gen_rtx_SYMBOL_REF (Pmode, name);
   SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
-  SYMBOL_REF_DECL (x) = decl;
+  SYMBOL_REF_DATA (x) = decl;
 
   x = gen_rtx_MEM (DECL_MODE (decl), x);
   if (TREE_CODE (decl) != FUNCTION_DECL)
@@ -2573,7 +2573,7 @@ build_constant_desc (tree exp)
   /* We have a symbol name; construct the SYMBOL_REF and the MEM.  */
   symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
   SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
-  SYMBOL_REF_DECL (symbol) = desc->value;
+  SYMBOL_REF_DATA (symbol) = desc->value;
   TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
 
   rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
@@ -2751,7 +2751,6 @@ struct rtx_constant_pool GTY(())
      constant addresses are restricted so that such constants must be stored
      in memory.  */
   htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
-  htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_sym_htab;
 
   /* Current offset in constant pool (does not include any
      machine-specific header).  */
@@ -2792,23 +2791,6 @@ const_desc_rtx_eq (const void *a, const void *b)
   return rtx_equal_p (x->constant, y->constant);
 }
 
-/* Hash and compare functions for const_rtx_sym_htab.  */
-
-static hashval_t
-const_desc_rtx_sym_hash (const void *ptr)
-{
-  const struct constant_descriptor_rtx *desc = ptr;
-  return htab_hash_string (XSTR (desc->sym, 0));
-}
-
-static int
-const_desc_rtx_sym_eq (const void *a, const void *b)
-{
-  const struct constant_descriptor_rtx *x = a;
-  const struct constant_descriptor_rtx *y = b;
-  return XSTR (x->sym, 0) == XSTR (y->sym, 0);
-}
-
 /* This is the worker function for const_rtx_hash, called via for_each_rtx.  */
 
 static int
@@ -2912,8 +2894,6 @@ init_varasm_status (struct function *f)
 
   pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
 					  const_desc_rtx_eq, NULL);
-  pool->const_rtx_sym_htab = htab_create_ggc (31, const_desc_rtx_sym_hash,
-					      const_desc_rtx_sym_eq, NULL);
   pool->first = pool->last = NULL;
   pool->offset = 0;
 }
@@ -2998,14 +2978,10 @@ force_const_mem (enum machine_mode mode, rtx x)
      the constants pool.  */
   desc->sym = symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
   SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
+  SYMBOL_REF_DATA (symbol) = desc;
   CONSTANT_POOL_ADDRESS_P (symbol) = 1;
   current_function_uses_const_pool = 1;
 
-  /* Insert the descriptor into the symbol cross-reference table too.  */
-  slot = htab_find_slot (pool->const_rtx_sym_htab, desc, INSERT);
-  gcc_assert (!*slot);
-  *slot = desc;
-
   /* Construct the MEM.  */
   desc->mem = def = gen_const_mem (mode, symbol);
   set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
@@ -3019,23 +2995,12 @@ force_const_mem (enum machine_mode mode, rtx x)
   return copy_rtx (def);
 }
 
-/* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
-   the corresponding constant_descriptor_rtx structure.  */
-
-static struct constant_descriptor_rtx *
-find_pool_constant (struct rtx_constant_pool *pool, rtx sym)
-{
-  struct constant_descriptor_rtx tmp;
-  tmp.sym = sym;
-  return htab_find (pool->const_rtx_sym_htab, &tmp);
-}
-
 /* Given a constant pool SYMBOL_REF, return the corresponding constant.  */
 
 rtx
 get_pool_constant (rtx addr)
 {
-  return find_pool_constant (cfun->varasm->pool, addr)->constant;
+  return SYMBOL_REF_CONSTANT (addr)->constant;
 }
 
 /* Given a constant pool SYMBOL_REF, return the corresponding constant
@@ -3046,25 +3011,17 @@ get_pool_constant_mark (rtx addr, bool *pmarked)
 {
   struct constant_descriptor_rtx *desc;
 
-  desc = find_pool_constant (cfun->varasm->pool, addr);
+  desc = SYMBOL_REF_CONSTANT (addr);
   *pmarked = (desc->mark != 0);
   return desc->constant;
 }
 
-/* Likewise, but for the constant pool of a specific function.  */
-
-rtx
-get_pool_constant_for_function (struct function *f, rtx addr)
-{
-  return find_pool_constant (f->varasm->pool, addr)->constant;
-}
-
 /* Similar, return the mode.  */
 
 enum machine_mode
 get_pool_mode (rtx addr)
 {
-  return find_pool_constant (cfun->varasm->pool, addr)->mode;
+  return SYMBOL_REF_CONSTANT (addr)->mode;
 }
 
 /* Return the size of the constant pool.  */
@@ -3208,7 +3165,7 @@ mark_constant (rtx *current_rtx, void *data)
 
   if (CONSTANT_POOL_ADDRESS_P (x))
     {
-      struct constant_descriptor_rtx *desc = find_pool_constant (pool, x);
+      struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
       if (desc->mark == 0)
 	{
 	  desc->mark = 1;