Index: gcc/ChangeLog

2002-09-12  Geoffrey Keating  <geoffk@apple.com>

	* ggc-common.c (ggc_mark_rtx_children_1): Update for changed name
	mangling.

	The following changes are merged from pch-branch:

	* doc/gty.texi (GTY Options): Document %a.
	* gengtype.c (do_scalar_typedef): New function.
	(process_gc_options): Handle `length' option.
	(set_gc_used_type): A pointer to an array of structures doesn't
	qualify as a pointer to a structure.
	(output_escaped_param): Add `%a' escape.
	(write_gc_structure_fields): Allow 'desc' on array of unions.
	(main): Define `uint8', `jword' and `JCF_u2' as scalars; use
	do_scalar_typedef.

	* gengtype.c (enum rtx_code): Make global.
	(rtx_format): Make global.
	(rtx_next): New.
	(gen_rtx_next): New.
	(write_rtx_next): New.
	(adjust_field_rtx_def): Skip fields marked by chain_next.
	(open_base_files): Delete redundant prototype.
	(write_enum_defn): New.
	(output_mangled_typename): Correct abort call.
	(write_gc_marker_routine_for_structure): Handle chain_next and
	chain_prev options.
	(finish_root_table): Don't output redundant \n.
	(main): Call gen_rtx_next, write_rtx_next, write_enum_defn.
	* c-tree.h (union lang_tree_node): Add chain_next option.

	* gengtype.h (NUM_PARAM): New definition.
	(struct type): For TYPE_PARAM_STRUCT, allow multiple parameters.
	* gengtype.c (find_param_structure): New.
	(adjust_field_type): Handle param<n>_is option.
	(process_gc_options): Detect use_params option.  Update callers.
	(set_gc_used_type): Add 'param' parameter, update callers.  Handle
	'use_params' option.
	(open_base_files): Add splay-tree.h to list of files included.
	(output_mangled_typename): New.
	(write_gc_structure_fields): Update 'param' parameter to support
	multiple parameters.  Change name mangling.  Allow parameterized
	fields to have an apparent scalar type.  Handle param<n>_is options,
	use_param option.
	(write_gc_marker_routine_for_structure): Update for change to name
	mangling.  Better guess the output file for parameterized types.
	(write_gc_types): Update for change to name mangling.
	(write_gc_root): Update for change to name mangling.  Handle (ignore)
	param<n>_is options.
	* doc/gty.texi (GTY Options): Add description of param<n>_is
	options, use_params option.
	* ggc.h (ggc_mark_rtx): Update for changed name mangling.
	* gengtype-lex.l: Produce token for param<n>_is.
	* gengtype-yacc.y: Parse param<n>_is.

	* gengtype.c (adjust_field_tree_exp): Don't name a variable 'rindex'.

	* rtl.c: Update comment describing rtx_format.
	* rtl.h (union rtunion): Separate definition and typedef.
	(struct rtx_def): Use gengtype to mark.
	* Makefile.in (gengtype.o): Also depend on rtl.def.
	* ggc.h (ggc_mark_rtx_children): Delete prototype.
	(ggc_mark_rtx): Change to alias of gengtype-generated routine.
	* ggc-common.c (ggc_mark_rtx_children): Delete.
	(ggc_mark_rtx_children_1): Delete.
	(gt_ggc_m_rtx_def): Delete.
	* gengtype.c (adjust_field_rtx_def): New.
	(adjust_field_type): Call adjust_field_rtx_def.
	(write_gc_structure_fields): Add 'default' case to switch if none
	is specified; remove unused code.

	* tree.h (struct tree_exp): Update for change to meaning
	of special.
	* gengtype.c (adjust_field_tree_exp): New function.
	(adjust_field_type): Handle `tree_exp' special here.
	(write_gc_structure_fields): Don't handle `tree_exp' special here.
	Handle new `dot' option.

	* gengtype.h: Make `info' a pointer-to-const.
	* gengtype-yacc.y (yacc_ids): Use xasprintf.

	* gengtype.c (write_gc_structure_fields): Remove implementation
	of `always' option, add `default' option.
	* doc/gty.texi (GTY Options): Remove documentation of `always',
	add `default'.

Index: gcc/cp/ChangeLog
2002-09-12  Geoffrey Keating  <geoffk@apple.com>

	* cp-tree.h (union lang_tree_node): Add chain_next option.

Index: gcc/f/ChangeLog
2002-09-12  Geoffrey Keating  <geoffk@apple.com>

	* com.c (union lang_tree_node): Add chain_next option.

Index: gcc/java/ChangeLog
2002-09-12  Geoffrey Keating  <geoffk@apple.com>

	* java-tree.h (union lang_tree_node): Add chain_next option.

From-SVN: r57206

gcc/ChangeLog

+2002-09-16  Geoffrey Keating  <geoffk@apple.com>
+
+	* ggc-common.c (ggc_mark_rtx_children_1): Update for changed name
+	mangling.
+
+	The following changes are merged from pch-branch:
+
+	* doc/gty.texi (GTY Options): Document %a.
+	* gengtype.c (do_scalar_typedef): New function.
+	(process_gc_options): Handle `length' option.
+	(set_gc_used_type): A pointer to an array of structures doesn't
+	qualify as a pointer to a structure.
+	(output_escaped_param): Add `%a' escape.
+	(write_gc_structure_fields): Allow 'desc' on array of unions.
+	(main): Define `uint8', `jword' and `JCF_u2' as scalars; use
+	do_scalar_typedef.
+
+	* gengtype.c (enum rtx_code): Make global.
+	(rtx_format): Make global.
+	(rtx_next): New.
+	(gen_rtx_next): New.
+	(write_rtx_next): New.
+	(adjust_field_rtx_def): Skip fields marked by chain_next.
+	(open_base_files): Delete redundant prototype.
+	(write_enum_defn): New.
+	(output_mangled_typename): Correct abort call.
+	(write_gc_marker_routine_for_structure): Handle chain_next and
+	chain_prev options.
+	(finish_root_table): Don't output redundant \n.
+	(main): Call gen_rtx_next, write_rtx_next, write_enum_defn.
+	* c-tree.h (union lang_tree_node): Add chain_next option.
+
+	* gengtype.h (NUM_PARAM): New definition.
+	(struct type): For TYPE_PARAM_STRUCT, allow multiple parameters.
+	* gengtype.c (find_param_structure): New.
+	(adjust_field_type): Handle param<n>_is option.
+	(process_gc_options): Detect use_params option.  Update callers.
+	(set_gc_used_type): Add 'param' parameter, update callers.  Handle
+	'use_params' option.
+	(open_base_files): Add splay-tree.h to list of files included.
+	(output_mangled_typename): New.
+	(write_gc_structure_fields): Update 'param' parameter to support
+	multiple parameters.  Change name mangling.  Allow parameterized
+	fields to have an apparent scalar type.  Handle param<n>_is options,
+	use_param option.
+	(write_gc_marker_routine_for_structure): Update for change to name
+	mangling.  Better guess the output file for parameterized types.
+	(write_gc_types): Update for change to name mangling.
+	(write_gc_root): Update for change to name mangling.  Handle (ignore)
+	param<n>_is options.
+	* doc/gty.texi (GTY Options): Add description of param<n>_is
+	options, use_params option.
+	* ggc.h (ggc_mark_rtx): Update for changed name mangling.
+	* gengtype-lex.l: Produce token for param<n>_is.
+	* gengtype-yacc.y: Parse param<n>_is.
+
+	* gengtype.c (adjust_field_tree_exp): Don't name a variable 'rindex'.
+
+	* rtl.c: Update comment describing rtx_format.
+	* rtl.h (union rtunion): Separate definition and typedef.
+	(struct rtx_def): Use gengtype to mark.
+	* Makefile.in (gengtype.o): Also depend on rtl.def.
+	* ggc.h (ggc_mark_rtx_children): Delete prototype.
+	(ggc_mark_rtx): Change to alias of gengtype-generated routine.
+	* ggc-common.c (ggc_mark_rtx_children): Delete.
+	(ggc_mark_rtx_children_1): Delete.
+	(gt_ggc_m_rtx_def): Delete.
+	* gengtype.c (adjust_field_rtx_def): New.
+	(adjust_field_type): Call adjust_field_rtx_def.
+	(write_gc_structure_fields): Add 'default' case to switch if none
+	is specified; remove unused code.
+
+	* tree.h (struct tree_exp): Update for change to meaning
+	of special.
+	* gengtype.c (adjust_field_tree_exp): New function.
+	(adjust_field_type): Handle `tree_exp' special here.
+	(write_gc_structure_fields): Don't handle `tree_exp' special here.
+	Handle new `dot' option.
+
+	* gengtype.h: Make `info' a pointer-to-const.
+	* gengtype-yacc.y (yacc_ids): Use xasprintf.
+
+	* gengtype.c (write_gc_structure_fields): Remove implementation
+	of `always' option, add `default' option.
+	* doc/gty.texi (GTY Options): Remove documentation of `always',
+	add `default'.
+
 2002-09-16  Hans-Peter Nilsson  <hp@bitrange.com>
 
 	* output.h: Remove #ifdef RTX_CODE and #ifdef TREE_CODE.

gcc/Makefile.in

@@ -2053,7 +2053,8 @@ gengtype$(build_exeext) : gengtype.o gengtype-lex.o gengtype-yacc.o \
 	$(HOST_CC) $(HOST_CFLAGS) $(HOST_LDFLAGS) -o $@ \
 	 gengtype.o gengtype-lex.o gengtype-yacc.o $(HOST_LIBS)
 
-gengtype.o : gengtype.c gengtype.h $(HCONFIG_H) $(SYSTEM_H) real.h gtyp-gen.h
+gengtype.o : gengtype.c gengtype.h $(HCONFIG_H) $(SYSTEM_H) real.h rtl.def \
+  gtyp-gen.h
 	$(HOST_CC) -c $(HOST_CFLAGS) $(HOST_CPPFLAGS) $(INCLUDES) \
 	  $(srcdir)/gengtype.c $(OUTPUT_OPTION)
 

gcc/c-tree.h

@@ -48,7 +48,8 @@ struct lang_identifier GTY(())
 /* The resulting tree type.  */
 
 union lang_tree_node 
-  GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE")))
+  GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
+       chain_next ("(union lang_tree_node *)TREE_CHAIN (&%h.generic)")))
 {
   union tree_node GTY ((tag ("0"), 
 			desc ("tree_node_structure (&%h)"))) 

gcc/cp/ChangeLog

+2002-09-16  Geoffrey Keating  <geoffk@apple.com>
+
+	* cp-tree.h (union lang_tree_node): Add chain_next option.
+
 2002-09-16  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* parse.y (parse_finish_call_expr): Check lookup_member result.

gcc/cp/cp-tree.h

@@ -505,7 +505,8 @@ enum cp_tree_node_structure_enum {
 };
 
 /* The resulting tree type.  */
-union lang_tree_node GTY((desc ("cp_tree_node_structure (&%h)")))
+union lang_tree_node GTY((desc ("cp_tree_node_structure (&%h)"),
+       chain_next ("(union lang_tree_node *)TREE_CHAIN (&%h.generic)")))
 {
   struct tree_common GTY ((tag ("TS_CP_COMMON"))) common;
   union tree_node GTY ((tag ("TS_CP_GENERIC"),

gcc/doc/gty.texi

@@ -72,6 +72,10 @@ immediately contains the current structure.
 @item %0
 This expands to an expression that evaluates to the outermost structure
 that contains the current structure.
+@item %a
+This expands to the string of the form @code{[i1][i2]...} that indexes
+the array item currently being marked.  For instance, if the field
+being marked is @code{foo}, then @code{%1.foo%a} is the same as @code{%h}.
 @end table
 
 The available options are:
@@ -121,10 +125,10 @@ field really isn't ever used.
 
 @findex desc
 @findex tag
-@findex always
+@findex default
 @item desc
 @itemx tag
-@itemx always
+@itemx default
 
 The type machinery needs to be told which field of a @code{union} is
 currently active.  This is done by giving each field a constant @code{tag}
@@ -146,7 +150,9 @@ it discriminates.  Use @code{%1} to mean the structure containing it.
 (There are no escapes available to the @code{tag} option, since it's
 supposed to be a constant.)
 
-You can use @code{always} to mean that this field is always used.
+Each @code{tag} should be different.  If no @code{tag} is matched,
+the field marked with @code{default} is used if there is one, otherwise
+no field in the union will be marked.
 
 @findex param_is
 @findex use_param
@@ -154,15 +160,39 @@ You can use @code{always} to mean that this field is always used.
 @itemx use_param
 
 Sometimes it's convenient to define some data structure to work on
-generic pointers (that is, @code{PTR}), and then use it with specific types.
-@code{param_is} specifies the real type pointed to, and @code{use_param}
-says where in the generic data structure that type should be put.
+generic pointers (that is, @code{PTR}) and then use it with a specific
+type.  @code{param_is} specifies the real type pointed to, and
+@code{use_param} says where in the generic data structure that type
+should be put.
 
 For instance, to have a @code{htab_t} that points to trees, one should write
 @verbatim
   htab_t GTY ((param_is (union tree_node))) ict;
 @end verbatim
 
+@findex param@var{n}_is
+@findex use_param@var{n}
+@item param@var{n}_is
+@itemx use_param@var{n}
+
+In more complicated cases, the data structure might need to work on
+several different types, which might not necessarily all be pointers.
+For this, @code{param1_is} through @code{param9_is} may be used to
+specify the real type of a field identified by @code{use_param1} through
+@code{use_param9}.
+
+@findex use_params
+@item use_params
+
+When a structure contains another structure that is parameterised,
+there's no need to do anything special, the inner stucture inherits the
+parameters of the outer one.  When a structure contains a pointer to a
+parameterised structure, the type machinery won't automatically detect
+this (it could, it just doesn't yet), so it's necessary to tell it that
+the pointed-to structure should use the same parameters as the outer
+structure.  This is done by marking the pointer with the
+@code{use_params} option.
+
 @findex deletable
 @item deletable
 

gcc/f/ChangeLog

+2002-09-16  Geoffrey Keating  <geoffk@apple.com>
+
+	* com.c (union lang_tree_node): Add chain_next option.
+
 2002-09-16  Richard Henderson  <rth@redhat.com>
 
 	* target.c (ffetarget_real1): Don't pass FFETARGET_ATOF_

gcc/f/com.c

@@ -605,7 +605,8 @@ struct lang_identifier GTY(())
 
 /* The resulting tree type.  */
 union lang_tree_node 
-  GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE")))
+  GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
+       chain_next ("(union lang_tree_node *)TREE_CHAIN (&%h.generic)")))
 {
   union tree_node GTY ((tag ("0"), 
 			desc ("tree_node_structure (&%h)"))) 

gcc/gengtype-lex.l

@@ -203,8 +203,11 @@ ITYPE	{IWORD}({WS}{IWORD})*
 "struct"/[^[:alnum:]_]		{ return STRUCT; }
 "enum"/[^[:alnum:]_]		{ return ENUM; }
 "ptr_alias"/[^[:alnum:]_]	{ return ALIAS; }
-"param_is"/[^[:alnum:]_]	{ return PARAM_IS; }
 [0-9]+				{ return NUM; }
+"param"[0-9]*"_is"/[^[:alnum:]_]		{ 
+  yylval.s = xmemdup (yytext, yyleng, yyleng+1);
+  return PARAM_IS;
+}
 
 {IWORD}({WS}{IWORD})*/[^[:alnum:]_]		|
 "ENUM_BITFIELD"{WS}?"("{WS}?{ID}{WS}?")"	{

gcc/gengtype-yacc.y

@@ -42,7 +42,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 %token STRUCT "struct"
 %token ENUM "enum"
 %token ALIAS "ptr_alias"
-%token PARAM_IS "param_is"
+%token <s>PARAM_IS
 %token NUM
 %token PERCENTPERCENT "%%"
 %token <t>SCALAR
@@ -174,8 +174,7 @@ yacc_ids: /* empty */
 	  p->opt = xmalloc (sizeof (*(p->opt)));
 	  p->opt->name = "tag";
 	  p->opt->next = NULL;
-	  p->opt->info = xmalloc (3 + strlen ($2));
-	  sprintf (p->opt->info, "'%s'", $2);
+	  p->opt->info = xasprintf ("'%s'", $2);
 	  $$ = p;
 	}
      ;
@@ -263,14 +262,14 @@ options: GTY_TOKEN '(' '(' optionseqopt ')' ')'
 type_option : ALIAS
 	        { $$ = "ptr_alias"; }
 	      | PARAM_IS
-	        { $$ = "param_is"; }
+	        { $$ = $1; }
 	      ;
 
 option:	type_option '(' type ')'
 	   {
 	     options_p o = xmalloc (sizeof (*o));
 	     o->name = $1;
-	     o->info = $3;
+	     o->info = adjust_field_type ($3, NULL);
 	     $$ = o;
 	   }
 	| ID '(' STRING ')'

gcc/gengtype.h

@@ -41,7 +41,7 @@ enum typekind {
 typedef struct options {
   struct options *next;
   const char *name;
-  void *info;
+  const void *info;
 } *options_p;
 
 typedef struct pair *pair_p;
@@ -57,6 +57,8 @@ struct pair {
   options_p opt;
 };
 
+#define NUM_PARAM 10
+
 /* A description of a type.  */
 struct type {
   enum typekind kind;
@@ -85,7 +87,7 @@ struct type {
     } a;
     struct {
       type_p stru;
-      type_p param;
+      type_p param[NUM_PARAM];
       struct fileloc line;
     } param_struct;
   } u;

gcc/ggc-common.c

@@ -34,7 +34,6 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 /* Statistics about the allocation.  */
 static ggc_statistics *ggc_stats;
 
-static void ggc_mark_rtx_children_1 PARAMS ((rtx));
 static int ggc_htab_delete PARAMS ((void **, void *));
 
 /* Maintain global roots that are preserved during GC.  */
@@ -132,140 +131,6 @@ ggc_mark_roots ()
 	htab_traverse (*cti->base, ggc_htab_delete, (PTR) cti);
 }
 
-/* R had not been previously marked, but has now been marked via
-   ggc_set_mark.  Now recurse and process the children.  */
-
-void
-ggc_mark_rtx_children (r)
-     rtx r;
-{
-  rtx i, last;
-
-  /* Special case the instruction chain.  This is a data structure whose
-     chain length is potentially unbounded, and which contain references
-     within the chain (e.g. label_ref and insn_list).  If do nothing here,
-     we risk blowing the stack recursing through a long chain of insns.
-
-     Combat this by marking all of the instructions in the chain before
-     marking the contents of those instructions.  */
-
-  switch (GET_CODE (r))
-    {
-    case INSN:
-    case JUMP_INSN:
-    case CALL_INSN:
-    case NOTE:
-    case CODE_LABEL:
-    case BARRIER:
-      for (i = NEXT_INSN (r); ; i = NEXT_INSN (i))
-	if (! ggc_test_and_set_mark (i))
-	  break;
-      last = i;
-
-      for (i = NEXT_INSN (r); i != last; i = NEXT_INSN (i))
-	ggc_mark_rtx_children_1 (i);
-
-    default:
-      break;
-    }
-
-  ggc_mark_rtx_children_1 (r);
-}
-
-static void
-ggc_mark_rtx_children_1 (r)
-     rtx r;
-{
-  const char *fmt;
-  int i;
-  rtx next_rtx;
-
-  do
-    {
-      enum rtx_code code = GET_CODE (r);
-      /* This gets set to a child rtx to eliminate tail recursion.  */
-      next_rtx = NULL;
-
-      /* Collect statistics, if appropriate.  */
-      if (ggc_stats)
-	{
-	  ++ggc_stats->num_rtxs[(int) code];
-	  ggc_stats->size_rtxs[(int) code] += ggc_get_size (r);
-	}
-
-      /* ??? If (some of) these are really pass-dependent info, do we
-	 have any right poking our noses in?  */
-      switch (code)
-	{
-	case MEM:
-	  gt_ggc_m_mem_attrs (MEM_ATTRS (r));
-	  break;
-	case JUMP_INSN:
-	  ggc_mark_rtx (JUMP_LABEL (r));
-	  break;
-	case CODE_LABEL:
-	  ggc_mark_rtx (LABEL_REFS (r));
-	  break;
-	case LABEL_REF:
-	  ggc_mark_rtx (LABEL_NEXTREF (r));
-	  ggc_mark_rtx (CONTAINING_INSN (r));
-	  break;
-	case ADDRESSOF:
-	  ggc_mark_tree (ADDRESSOF_DECL (r));
-	  break;
-	case NOTE:
-	  switch (NOTE_LINE_NUMBER (r))
-	    {
-	    case NOTE_INSN_EXPECTED_VALUE:
-	      ggc_mark_rtx (NOTE_EXPECTED_VALUE (r));
-	      break;
-
-	    case NOTE_INSN_BLOCK_BEG:
-	    case NOTE_INSN_BLOCK_END:
-	      ggc_mark_tree (NOTE_BLOCK (r));
-	      break;
-
-	    default:
-	      break;
-	    }
-	  break;
-
-	default:
-	  break;
-	}
-
-      for (fmt = GET_RTX_FORMAT (GET_CODE (r)), i = 0; *fmt ; ++fmt, ++i)
-	{
-	  rtx exp;
-	  switch (*fmt)
-	    {
-	    case 'e': case 'u':
-	      exp = XEXP (r, i);
-	      if (ggc_test_and_set_mark (exp))
-		{
-		  if (next_rtx == NULL)
-		    next_rtx = exp;
-		  else
-		    ggc_mark_rtx_children (exp);
-		}
-	      break;
-	    case 'V': case 'E':
-	      gt_ggc_m_rtvec_def (XVEC (r, i));
-	      break;
-	    }
-	}
-    }
-  while ((r = next_rtx) != NULL);
-}
-
-/* Various adaptor functions.  */
-void
-gt_ggc_mx_rtx_def (x)
-     void *x;
-{
-  ggc_mark_rtx((rtx)x);
-}
-
 /* Allocate a block of memory, then clear it.  */
 void *
 ggc_alloc_cleared (size)

gcc/ggc.h

 /* Garbage collection for the GNU compiler.
-   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -62,21 +62,13 @@ extern const struct ggc_cache_tab * const gt_ggc_cache_rtab[];
 
 extern void ggc_mark_roots		PARAMS ((void));
 
-extern void ggc_mark_rtx_children	PARAMS ((struct rtx_def *));
-
 /* If EXPR is not NULL and previously unmarked, mark it and evaluate
    to true.  Otherwise evaluate to false.  */
 #define ggc_test_and_set_mark(EXPR) \
   ((EXPR) != NULL && ((void *) (EXPR)) != (void *) 1 && ! ggc_set_mark (EXPR))
 
-#define ggc_mark_rtx(EXPR)                      \
-  do {                                          \
-    rtx const r__ = (EXPR);                     \
-    if (ggc_test_and_set_mark (r__))            \
-      ggc_mark_rtx_children (r__);              \
-  } while (0)
-
-#define ggc_mark_tree gt_ggc_m_tree_node
+#define ggc_mark_rtx gt_ggc_m_7rtx_def
+#define ggc_mark_tree gt_ggc_m_9tree_node
 
 #define ggc_mark(EXPR)				\
   do {						\

gcc/java/ChangeLog

+2002-09-16  Geoffrey Keating  <geoffk@apple.com>
+
+	* java-tree.h (union lang_tree_node): Add chain_next option.
+
 2002-09-16  Richard Henderson  <rth@redhat.com>
 
 	* jcf-parse.c (get_constant): Runtime check for IEEE format;

gcc/java/java-tree.h

@@ -693,7 +693,8 @@ struct lang_identifier GTY(())
 
 /* The resulting tree type.  */
 union lang_tree_node 
-  GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE")))
+  GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
+       chain_next ("(union lang_tree_node *)TREE_CHAIN (&%h.generic)")))
 {
   union tree_node GTY ((tag ("0"), 
 			desc ("tree_node_structure (&%h)"))) 

gcc/rtl.c

@@ -186,6 +186,7 @@ const char * const rtx_format[NUM_RTX_CODE] = {
      "u" a pointer to another insn
          prints the uid of the insn.
      "b" is a pointer to a bitmap header.
+     "B" is a basic block pointer.
      "t" is a tree pointer.  */
 
 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS)   FORMAT ,

gcc/rtl.h

@@ -62,6 +62,8 @@ extern const char * const rtx_format[NUM_RTX_CODE];
 
 extern const char rtx_class[NUM_RTX_CODE];
 #define GET_RTX_CLASS(CODE)		(rtx_class[(int) (CODE)])
+
+extern const unsigned char rtx_next[NUM_RTX_CODE];
 
 /* The flags and bitfields of an ADDR_DIFF_VEC.  BASE is the base label
    relative to which the offsets are calculated, as explained in rtl.def.  */
@@ -103,7 +105,7 @@ typedef struct mem_attrs GTY(())
 
 /* Common union for an element of an rtx.  */
 
-typedef union rtunion_def
+union rtunion_def
 {
   HOST_WIDE_INT rtwint;
   int rtint;
@@ -118,11 +120,13 @@ typedef union rtunion_def
   tree rttree;
   struct basic_block_def *bb;
   mem_attrs *rtmem;
-} rtunion;
+};
+typedef union rtunion_def rtunion;
 
 /* RTL expression ("rtx").  */
 
-struct rtx_def
+struct rtx_def GTY((chain_next ("RTX_NEXT (&%h)"), 
+		    chain_prev ("RTX_PREV (&%h)")))
 {
   /* The kind of expression this is.  */
   ENUM_BITFIELD(rtx_code) code: 16;
@@ -198,11 +202,29 @@ struct rtx_def
   /* The first element of the operands of this rtx.
      The number of operands and their types are controlled
      by the `code' field, according to rtl.def.  */
-  rtunion fld[1];
+  rtunion GTY ((special ("rtx_def"),
+		desc ("GET_CODE (&%0)"))) fld[1];
 };
 
 #define NULL_RTX (rtx) 0
 
+/* The "next" and "previous" RTX, relative to this one.  */
+
+#define RTX_NEXT(X) (rtx_next[GET_CODE (X)] == 0 ? NULL			\
+		     : *(rtx *)(((char *)X) + rtx_next[GET_CODE (X)]))
+
+/* FIXME: the "NEXT_INSN (PREV_INSN (X)) == X" condition shouldn't be needed.
+ */
+#define RTX_PREV(X) ((GET_CODE (X) == INSN              \
+                      || GET_CODE (X) == CALL_INSN      \
+                      || GET_CODE (X) == JUMP_INSN      \
+                      || GET_CODE (X) == NOTE           \
+                      || GET_CODE (X) == BARRIER        \
+                      || GET_CODE (X) == CODE_LABEL)    \
+                     && PREV_INSN (X) != NULL           \
+                     && NEXT_INSN (PREV_INSN (X)) == X  \
+                     ? PREV_INSN (X) : NULL)
+
 /* Define macros to access the `code' field of the rtx.  */
 
 #define GET_CODE(RTX)	    ((enum rtx_code) (RTX)->code)

gcc/tree.h

@@ -889,7 +889,7 @@ struct tree_exp GTY(())
   struct tree_common common;
   int complexity;
   tree GTY ((special ("tree_exp"), 
-	     length ("TREE_CODE_LENGTH (TREE_CODE ((tree) &%h))"))) 
+	     desc ("TREE_CODE ((tree) &%0)"))) 
     operands[1];
 };