* doc/tree-ssa.texi: Remove references to VDEF and add descriptions

	of V_MAY_DEF and V_MUST_DEF.
	* tree-dfa.c (dfa_stats_d): Add num_v_must_defs and rename
	num_vdefs to num_v_may_defs.
	(compute_immediate_uses_for_stmt): Rename occurences of vdef
	to v_may_def.
	(redirect_immediate_uses): Ditto.
	(dump_dfa_stats): Ditto. Also added code to dump num_v_must_defs.
	(collect_dfa_stats_r): Rename occurences of vdef to v_may_def.
	Also add code to sum up the number of v_must_defs.
	(vdefs_disappeared_p): Replace with...
	(v_may_defs_disappeared_p): This.
	(v_must_defs_disappeared_p): New function.
	(mark_new_vars_to_rename): Rename occurences of vdef to v_may_def.
	Also add code to mark new variables found in V_MUST_DEFs for
	renameing.
	* tree-flow.h (stmt_ann_d): Add v_must_def_ops and replace
	vdef_ops to v_may_def_ops.
	(get_vdef_ops): Replace with...
	(get_v_may_def_ops): This.
	* tree-flow-inline.h (get_vdef_ops): Replace with...
	(get_v_may_def_ops): This.
	(get_v_must_def_ops): New function.
	(get_vdef_result_ptr): Replace with...
	(get_v_may_def_result_ptr): This.
	(get_vdef_op_ptr): Ditto with...
	(get_v_may_def_op_ptr); This.
	(get_v_must_def_op_ptr): New function.
	* tree-into-ssa.c (mark_def_sites): Rename occurences of vdef
	to v_may_def. Also add code to mark statements with
	V_MUST_DEFs as definition sites.
	(rewrite_stmt): Rename occurences of vdef to v_may_def. Also
	add code to register new V_MUST_DEFs made by the statement.
	* tree-outof-ssa.c (VIRTUAL_PARTITION): Update comments.
	(check_replaceable): Rename occurences of vdef to v_may_def. Also
	add check for V_MUST_DEFs.
	(find_replaceable_in_bb): Ditto.
	* tree-pretty-print.c (dump_vops): Rename occurences of vdef
	to v_may_def. Also add code to dump V_MUST_DEFs.
	* tree-sra.c (mark_all_vdefs): Replace with...
	(mark_all_v_may_defs): This.
	(mark_all_v_must_defs): New function.
	(create_scalar_copies): Replace call to mark_all_vdefs with
	calls to mark_all_v_may_defs and mark_all_v_must_defs.
	(scalarize_structures): Rename occurences of vdef to v_may_def.
	Also add a check for V_MUST_DEFs.
	(scalarize_modify_expr): Rename occurences of vdef to v_may_def.
	* tree-ssa-alias.c (global_var): Update comment.
	(compute_may_aliases): Ditto.
	(compute_points_to_and_addr_escape): Rename occurences of vdef
	to v_may_def. Also add code to mark variables in V_MUST_DEF
	operands as being written to.
	(group_aliases): Update comment.
	(maybe_create_global_var): Ditto.
	* tree-ssa.c (verify_ssa): Rename occurences of vdef to v_may_def.
	Also add a check for V_MUST_DEFs on GIMPLE registers.
	(replace_immediate_uses): Rename occurences of vdef to v_may_def.
	* tree-ssa-ccp.c (visit_stmt): Rename occurences of vdef
	to v_may_def. Also add code to mark all V_MUST_DEF operands
	VARYING.
	(initialize): Ditto.
	(set_rhs): Rename occurences of vdef to v_may_def. Also add
	code to update SSA_NAMEs in V_MUST_DEFs.
	* tree-ssa-copy.c (cprop_into_stmt): Rename occurences of vdef
	to v_may_def.
	* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Rename
	occurences of vdef to v_may_def. Also add code to mark statements
	with V_MUST_DEFs as necessary.
	(propagate_necessity): Rename occurences of vdef to v_may_def.
	* tree-ssa-dom.c (redirect_edges_and_update_ssa_graph): Rename
	occurences of vdef to v_may_def. Also add code to mark operands
	in V_MUST_DEFs for renaming.
	(eliminate_redundant_computations): Rename occurences of vdef
	to v_may_def.
	(record_equivalences_from_stmt): Rename occurences of vdef
	to v_may_def. Also add code to record VUSEs for V_MUST_DEFs.
	(optimize_stmt): Remove unnesessary variable vdefs. Update
	comment.
	(register_definitions_for_stmt): Rename occurences of vdef
	to v_may_def. Also add code to register definitions made with
	V_MUST_DEFs.
	* tree-ssa-dse.c (fix_stmt_vdefs): Replace with...
	(fix_stmt_v_may_defs): This.
	(fix_phi_uses): Rename occurences of vdef to v_may_def.
	(dse_optimize_stmt): Ditto.
	* tree-ssa-live.c (create_ssa_var_map): Rename occurences of vdef
	to v_may_def. Also add code to mark V_MUST_DEF operands as being
	used in virtual operators.
	* tree-ssa-loop.c (mark_defs_for_rewrite): Rename occurences of
	vdef to v_may_def. Also add code to mark V_MUST_DEF operands for
	renaming.
	* tree-ssa-operands.c (opf_kill_def): New flag for killing
	definitions.
	(build_vdefs): Renamed to...
	(build_v_may_defs): This.
	(build_v_must_defs): New variable.
	(voperands_d): Add v_must_def_ops and replace vdef_ops with
	v_may_def_ops.
	(append_vdef): Replace with...
	(append_v_may_def): This.
	(append_v_must_def): New function.
	(NUM_FREE): Increment for V_MUST_DEF
	(optype_freelist): Increment its size for V_MUST_DEF
	(allocate_vdef_optype): Replace with...
	(allocate_v_may_def_optype): This.
	(allocate_v_must_def_optype): New function.
	(free_vdefs): Replace with...
	(free_v_may_defs): This.
	(free_v_must_defs): New function.
	(remove_vdefs): Replace with...
	(remove_v_may_defs): This.
	(remove_v_must_defs): New function.
	(init_ssa_operands): Rename occurences of vdef to v_may_def. Also
	add code to initialize build_v_must_defs.
	(finalize_ssa_vdefs): Replace with...
	(finalize_ssa_v_may_defs): This.
	(finalize_ssa_vuses): Rename occurences of vdef to v_may_def.
	(finalize_ssa_v_must_defs): New function.
	(finalize_ssa_stmt_operands): Replace call to finalize_ssa_vdefs
	with calls to finalize_ssa_v_may_defs and finalize_ssa_v_must_defs.
	(verify_start_operands): Rename occurences of vdef to v_may_def.
	Also add check for build_v_must_defs.
	(get_stmt_operands): Rename occurences of vdef to v_may_def.
	Also add code to handle V_MUST_DEFs and to use opf_kill_def for
	killing definitions.
	(get_expr_operands): Update comment and use opf_kill_def for
	killing definitions.
	(add_stmt_operand): Replace code that appends VDEFs with code
	that appends V_MUST_DEFs when opf_kill_def is set and V_MAY_DEFs
	otherwise.
	(add_call_clobber_ops): Update comments.
	* tree-ssa-operands.h (vdef_optype_d): Replace with...
	(v_may_def_optype_d): This.
	(v_must_def_optype_d): New structure.
	(VDEF_OPS): Replace with...
	(V_MAY_DEF_OPS): This.
	(STMT_VDEF_OPS): Same with...
	(STMT_V_MAY_DEF_OPS): This.
	(NUM_VDEFS): And...
	(NUM_V_MAY_DEFS): This.
	(VDEF_RESULT_PTR): As well as...
	(V_MAY_DEF_RESULT_PTR): This.
	(VDEF_RESULT): Same goes for...
	(V_MAY_DEF_RESULT): This.
	(VDEF_OP_PTR): And...
	(V_MAY_DEF_OP_PTR): This.
	(VDEF_OP): And...
	(V_MAY_DEF_OP): This.
	(V_MUST_DEF_OPS): New macro.
	(STMT_V_MUST_DEF_OPS): Ditto.
	(NUM_V_MUST_DEFS): Ditto.
	(V_MUST_DEF_OP_PTR): Ditto.
	(V_MUST_DEF_OP): Ditto.
	(remove_vdefs): Replace signature with...
	(remove_v_may_defs): This.
	(remove_v_must_defs): New function signature.
	* tree-ssa-pre.c (subst_phis): Replace call to remove_vdefs
	with calls to remove_v_may_defs and remove_v_must_defs.
	(process_left_occs_and_kills): Rename occurences of vdef to v_may_def.
	Also add code that marks left occurences of operands in V_MUST_DEFs.
	* tree-tailcall.c (find_tail_calls): Rename occurences of vdef
	to v_may_def. Also add check for V_MUST_DEFs.
	(eliminate_tail_call):Rename occurences of vdef to v_may_def.

testsuite:

	* gcc.dg/tree-ssa/20031015-1.c: Scan for
	V_MAY_DEF instead of VDEF.
	* gcc.dg/tree-ssa/20040517-1.c: Ditto.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@82947 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 48 insertions, 17 deletions

diff --git a/gcc/tree-into-ssa.c b/gcc/tree-into-ssa.c
index 7bb9c58f046..e07258a2894 100644
--- a/gcc/tree-into-ssa.c
+++ b/gcc/tree-into-ssa.c
@@ -211,7 +211,8 @@ mark_def_sites (struct dom_walk_data *walk_data,
 {
   struct mark_def_sites_global_data *gd = walk_data->global_data;
   sbitmap kills = gd->kills;
-  vdef_optype vdefs;
+  v_may_def_optype v_may_defs;
+  v_must_def_optype v_must_defs;
   vuse_optype vuses;
   def_optype defs;
   use_optype uses;
@@ -248,22 +249,36 @@ mark_def_sites (struct dom_walk_data *walk_data,
     }
 
   /* Note that virtual definitions are irrelevant for computing KILLS
-     because a VDEF does not constitute a killing definition of the
+     because a V_MAY_DEF does not constitute a killing definition of the
      variable.  However, the operand of a virtual definitions is a use
      of the variable, so it may cause the variable to be considered
      live-on-entry.  */
-  vdefs = VDEF_OPS (ann);
-  for (i = 0; i < NUM_VDEFS (vdefs); i++)
+  v_may_defs = V_MAY_DEF_OPS (ann);
+  for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++)
     {
-      if (prepare_operand_for_rename (VDEF_OP_PTR (vdefs, i), &uid, true))
+      if (prepare_operand_for_rename (V_MAY_DEF_OP_PTR (v_may_defs, i), 
+                                      &uid, true))
 	{
 	  /* If we do not already have an SSA_NAME for our destination,
 	     then set the destination to the source.  */
-	  if (TREE_CODE (VDEF_RESULT (vdefs, i)) != SSA_NAME)
-	    VDEF_RESULT (vdefs, i) = VDEF_OP (vdefs, i);
+	  if (TREE_CODE (V_MAY_DEF_RESULT (v_may_defs, i)) != SSA_NAME)
+	    V_MAY_DEF_RESULT (v_may_defs, i) = V_MAY_DEF_OP (v_may_defs, i);
+	    
+          set_livein_block (V_MAY_DEF_OP (v_may_defs, i), bb);
+	  set_def_block (V_MAY_DEF_RESULT (v_may_defs, i), bb);
+	}
+    }
+
+  /* Now process the virtual must-defs made by this statement.  */
+  v_must_defs = V_MUST_DEF_OPS (ann);
+  for (i = 0; i < NUM_V_MUST_DEFS (v_must_defs); i++)
+    {
+      tree *def_p = V_MUST_DEF_OP_PTR (v_must_defs, i);
 
-	  set_livein_block (VDEF_OP (vdefs, i), bb);
-	  set_def_block (VDEF_RESULT (vdefs, i), bb);
+      if (prepare_operand_for_rename (def_p, &uid, false))
+	{
+	  set_def_block (*def_p, bb);
+	  SET_BIT (kills, uid);
 	}
     }
 
@@ -717,7 +732,8 @@ rewrite_stmt (struct dom_walk_data *walk_data,
   stmt_ann_t ann;
   tree stmt;
   vuse_optype vuses;
-  vdef_optype vdefs;
+  v_may_def_optype v_may_defs;
+  v_must_def_optype v_must_defs;
   def_optype defs;
   use_optype uses;
   struct rewrite_block_data *bd;
@@ -744,7 +760,8 @@ rewrite_stmt (struct dom_walk_data *walk_data,
   defs = DEF_OPS (ann);
   uses = USE_OPS (ann);
   vuses = VUSE_OPS (ann);
-  vdefs = VDEF_OPS (ann);
+  v_may_defs = V_MAY_DEF_OPS (ann);
+  v_must_defs = V_MUST_DEF_OPS (ann);
 
   /* Step 1.  Rewrite USES and VUSES in the statement.  */
   for (i = 0; i < NUM_USES (uses); i++)
@@ -768,18 +785,32 @@ rewrite_stmt (struct dom_walk_data *walk_data,
     }
 
   /* Register new virtual definitions made by the statement.  */
-  for (i = 0; i < NUM_VDEFS (vdefs); i++)
+  for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++)
     {
-      rewrite_operand (VDEF_OP_PTR (vdefs, i));
+      rewrite_operand (V_MAY_DEF_OP_PTR (v_may_defs, i));
 
-      if (TREE_CODE (VDEF_RESULT (vdefs, i)) != SSA_NAME)
-	*VDEF_RESULT_PTR (vdefs, i)
-	  = make_ssa_name (VDEF_RESULT (vdefs, i), stmt);
+      if (TREE_CODE (V_MAY_DEF_RESULT (v_may_defs, i)) != SSA_NAME)
+	*V_MAY_DEF_RESULT_PTR (v_may_defs, i)
+	  = make_ssa_name (V_MAY_DEF_RESULT (v_may_defs, i), stmt);
 
       /* FIXME: We shouldn't be registering new defs if the variable
 	 doesn't need to be renamed.  */
-      register_new_def (VDEF_RESULT (vdefs, i), &bd->block_defs);
+      register_new_def (V_MAY_DEF_RESULT (v_may_defs, i), &bd->block_defs);
+    }
+        
+  /* Register new virtual mustdefs made by the statement.  */
+  for (i = 0; i < NUM_V_MUST_DEFS (v_must_defs); i++)
+    {
+      tree *v_must_def_p = V_MUST_DEF_OP_PTR (v_must_defs, i);
+
+      if (TREE_CODE (*v_must_def_p) != SSA_NAME)
+	*v_must_def_p = make_ssa_name (*v_must_def_p, stmt);
+
+      /* FIXME: We shouldn't be registering new mustdefs if the variable
+	 doesn't need to be renamed.  */
+      register_new_def (*v_must_def_p, &bd->block_defs);
     }
+    
 }