gimple.h (gimple_can_coalesce_p): Prototype.

	* gimple.h (gimple_can_coalesce_p): Prototype.
	* tree-ssa-coalesce.c (gimple_can_coalesce_p): New function.
	(create_outofssa_var_map, coalesce_partitions): Use it.
	* tree-ssa-uncprop.c (uncprop_into_successor_phis): Similarly.
	* tree-ssa-live.c (var_map_base_init): Use TYPE_CANONICAL
	if it's available.

	* gcc.dg/tree-ssa/coalesce-1.c: New test.

From-SVN: r200103

5 files changed, 250 insertions, 20 deletions

diff --git a/gcc/gimple.h b/gcc/gimple.h
index b4de403..8ae07c9 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -1101,6 +1101,9 @@ extern tree tree_ssa_strip_useless_type_conversions (tree);
 extern bool useless_type_conversion_p (tree, tree);
 extern bool types_compatible_p (tree, tree);
 
+/* In tree-ssa-coalesce.c */
+extern bool gimple_can_coalesce_p (tree, tree);
+
 /* Return the first node in GIMPLE sequence S.  */
 
 static inline gimple_seq_node
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/coalesce-1.c b/gcc/testsuite/gcc.dg/tree-ssa/coalesce-1.c
new file mode 100644
index 0000000..5cae9ae
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/coalesce-1.c
@@ -0,0 +1,195 @@
+/* { dg-do compile } */
+
+/* { dg-options "-O2 -fdump-rtl-expand-details" } */
+
+typedef long unsigned int size_t;
+union tree_node;
+typedef union tree_node *tree;
+union gimple_statement_d;
+typedef union gimple_statement_d *gimple;
+typedef const union tree_node *const_tree;
+typedef const union gimple_statement_d *const_gimple;
+struct gimple_seq_d;
+typedef struct gimple_seq_d *gimple_seq;
+struct edge_def;
+typedef struct edge_def *edge;
+struct basic_block_def;
+typedef struct basic_block_def *basic_block;
+typedef const struct basic_block_def *const_basic_block;
+struct tree_exp
+{
+  tree operands[1];
+};
+typedef struct ssa_use_operand_d
+{
+  tree *use;
+} ssa_use_operand_t;
+struct phi_arg_d
+{
+  struct ssa_use_operand_d imm_use;
+};
+union tree_node
+{
+  struct tree_exp exp;
+};
+struct function
+{
+};
+extern struct function *cfun;
+struct edge_def
+{
+  unsigned int dest_idx;
+};
+static __inline__ void
+VEC_edge_must_be_pointer_type (void)
+{
+  (void) ((edge) 1 == (void *) 1);
+} typedef struct VEC_edge_base
+
+{
+  unsigned num;
+  unsigned alloc;
+  edge vec[1];
+} VEC_edge_base;
+typedef struct VEC_edge_none
+{
+  VEC_edge_base base;
+} VEC_edge_none;
+
+static __inline__ edge
+VEC_edge_base_index (const VEC_edge_base * vec_, unsigned ix_,
+		     const char *file_, unsigned line_, const char *function_)
+{
+  return vec_->vec[ix_];
+}
+
+typedef struct VEC_edge_gc
+{
+  VEC_edge_base base;
+} VEC_edge_gc;
+struct basic_block_def
+{
+  VEC_edge_gc *succs;
+};
+static __inline__ edge
+single_succ_edge (const_basic_block bb)
+{
+  return (VEC_edge_base_index
+	  ((((bb)->succs) ? &((bb)->succs)->base : 0), (0),
+	   "/home/gcc/virgin-gcc/gcc/basic-block.h", 563, __FUNCTION__));
+}
+
+edge find_edge (basic_block, basic_block);
+typedef tree *def_operand_p;
+typedef ssa_use_operand_t *use_operand_p;
+struct gimple_seq_node_d;
+typedef struct gimple_seq_node_d *gimple_seq_node;
+struct gimple_seq_node_d
+{
+  gimple stmt;
+};
+typedef struct
+{
+  gimple_seq_node ptr;
+  gimple_seq seq;
+  basic_block bb;
+} gimple_stmt_iterator;
+struct gimple_statement_phi
+{
+  struct phi_arg_d args[1];
+};
+union gimple_statement_d
+{
+  struct gimple_statement_phi gimple_phi;
+};
+extern size_t const gimple_ops_offset_[];
+static __inline__ tree *
+gimple_ops (gimple gs)
+{
+  size_t off;
+  off = gimple_ops_offset_[gimple_statement_structure (gs)];
+  return (tree *) ((char *) gs + off);
+}
+
+static __inline__ tree
+gimple_op (const_gimple gs, unsigned i)
+{
+  return gimple_ops ((((union
+			{
+			const union gimple_statement_d * _q;
+			union gimple_statement_d * _nq;}) (((gs))))._nq))[i];
+}
+
+static __inline__ struct phi_arg_d *
+gimple_phi_arg (gimple gs, unsigned index)
+{
+  return &(gs->gimple_phi.args[index]);
+}
+
+static __inline__ tree
+gimple_switch_label (const_gimple gs, unsigned index)
+{
+  return gimple_op (gs, index + 1);
+}
+
+gimple_stmt_iterator gsi_start_phis (basic_block);
+extern basic_block label_to_block_fn (struct function *, tree);
+
+static __inline__ tree
+get_use_from_ptr (use_operand_p use)
+{
+  return *(use->use);
+}
+
+static __inline__ use_operand_p
+gimple_phi_arg_imm_use_ptr (gimple gs, int i)
+{
+  return &gimple_phi_arg (gs, i)->imm_use;
+}
+
+struct switch_conv_info
+{
+  basic_block final_bb;
+  basic_block switch_bb;
+  const char *reason;
+  tree *default_values;
+};
+static struct switch_conv_info info;
+
+static void
+gather_default_values (tree default_case)
+{
+  gimple_stmt_iterator gsi;
+  basic_block bb =
+    (label_to_block_fn ((cfun + 0), default_case->exp.operands[2]));
+  edge e;
+  int i = 0;
+  if (bb == info.final_bb)
+    e = find_edge (info.switch_bb, bb);
+  else
+    e = single_succ_edge (bb);
+  for (gsi = gsi_start_phis (info.final_bb);
+       gsi_gsi_start_phis (info.final_bb); gsi_next (&gsi))
+    {
+      gimple phi = gsi.ptr->stmt;
+      tree val = get_use_from_ptr (gimple_phi_arg_imm_use_ptr
+				   ((((phi))), (((e)->dest_idx))));
+      info.default_values[i++] = val;
+    }
+}
+
+unsigned char
+process_switch (gimple swtch)
+{
+  unsigned int i, branch_num = gimple_switch_num_labels (swtch);
+  tree index_type;
+  info.reason = "switch has no labels\n";
+  gather_default_values (gimple_switch_label (swtch, 0));
+}
+
+/* Verify that out-of-ssa coalescing did its job by verifying there are not
+   any partition copies inserted.  */
+
+/* { dg-final { scan-rtl-dump-not "partition copy" "expand"} } */
+/* { dg-final { cleanup-rtl-dump "expand" } } */
+
diff --git a/gcc/tree-ssa-coalesce.c b/gcc/tree-ssa-coalesce.c
index 354b5f1..d647191 100644
--- a/gcc/tree-ssa-coalesce.c
+++ b/gcc/tree-ssa-coalesce.c
@@ -943,8 +943,7 @@ create_outofssa_var_map (coalesce_list_p cl, bitmap used_in_copy)
 		continue;
 
 	      register_ssa_partition (map, arg);
-	      if ((SSA_NAME_VAR (arg) == SSA_NAME_VAR (res)
-		   && TREE_TYPE (arg) == TREE_TYPE (res))
+	      if (gimple_can_coalesce_p (arg, res)
 		  || (e->flags & EDGE_ABNORMAL))
 		{
 		  saw_copy = true;
@@ -985,8 +984,7 @@ create_outofssa_var_map (coalesce_list_p cl, bitmap used_in_copy)
 		if (gimple_assign_copy_p (stmt)
                     && TREE_CODE (lhs) == SSA_NAME
 		    && TREE_CODE (rhs1) == SSA_NAME
-		    && SSA_NAME_VAR (lhs) == SSA_NAME_VAR (rhs1)
-		    && TREE_TYPE (lhs) == TREE_TYPE (rhs1))
+		    && gimple_can_coalesce_p (lhs, rhs1))
 		  {
 		    v1 = SSA_NAME_VERSION (lhs);
 		    v2 = SSA_NAME_VERSION (rhs1);
@@ -1037,8 +1035,7 @@ create_outofssa_var_map (coalesce_list_p cl, bitmap used_in_copy)
 		    v1 = SSA_NAME_VERSION (outputs[match]);
 		    v2 = SSA_NAME_VERSION (input);
 
-		    if (SSA_NAME_VAR (outputs[match]) == SSA_NAME_VAR (input)
-			&& TREE_TYPE (outputs[match]) == TREE_TYPE (input))
+		    if (gimple_can_coalesce_p (outputs[match], input))
 		      {
 			cost = coalesce_cost (REG_BR_PROB_BASE,
 					      optimize_bb_for_size_p (bb));
@@ -1072,8 +1069,7 @@ create_outofssa_var_map (coalesce_list_p cl, bitmap used_in_copy)
 		first = var;
 	      else
 		{
-		  gcc_assert (SSA_NAME_VAR (var) == SSA_NAME_VAR (first)
-			      && TREE_TYPE (var) == TREE_TYPE (first));
+		  gcc_assert (gimple_can_coalesce_p (var, first));
 		  v1 = SSA_NAME_VERSION (first);
 		  v2 = SSA_NAME_VERSION (var);
 		  bitmap_set_bit (used_in_copy, v1);
@@ -1210,8 +1206,7 @@ coalesce_partitions (var_map map, ssa_conflicts_p graph, coalesce_list_p cl,
       var2 = ssa_name (y);
 
       /* Assert the coalesces have the same base variable.  */
-      gcc_assert (SSA_NAME_VAR (var1) == SSA_NAME_VAR (var2)
-		  && TREE_TYPE (var1) == TREE_TYPE (var2));
+      gcc_assert (gimple_can_coalesce_p (var1, var2));
 
       if (debug)
 	fprintf (debug, "Coalesce list: ");
@@ -1341,3 +1336,38 @@ coalesce_ssa_name (void)
 
   return map;
 }
+
+/* Given SSA_NAMEs NAME1 and NAME2, return true if they are candidates for
+   coalescing together, false otherwise.
+
+   This must stay consistent with var_map_base_init in tree-ssa-live.c.  */
+
+bool
+gimple_can_coalesce_p (tree name1, tree name2)
+{
+  /* First check the SSA_NAME's associated DECL.  We only want to
+     coalesce if they have the same DECL or both have no associated DECL.  */
+  if (SSA_NAME_VAR (name1) != SSA_NAME_VAR (name2))
+    return false;
+
+  /* Now check the types.  If the types are the same, then we should
+     try to coalesce V1 and V2.  */
+  tree t1 = TREE_TYPE (name1);
+  tree t2 = TREE_TYPE (name2);
+  if (t1 == t2)
+    return true;
+
+  /* If the types are not the same, check for a canonical type match.  This
+     (for example) allows coalescing when the types are fundamentally the
+     same, but just have different names. 
+
+     Note pointer types with different address spaces may have the same
+     canonical type.  Those are rejected for coalescing by the
+     types_compatible_p check.  */
+  if (TYPE_CANONICAL (t1)
+      && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2)
+      && types_compatible_p (t1, t2))
+    return true;
+
+  return false;
+}
diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c
index 83a52a0..a624d00 100644
--- a/gcc/tree-ssa-live.c
+++ b/gcc/tree-ssa-live.c
@@ -111,8 +111,12 @@ var_map_base_init (var_map map)
 	   as it restricts the sets we compute conflicts for.
 	   Using TREE_TYPE to generate sets is the easies as
 	   type equivalency also holds for SSA names with the same
-	   underlying decl.  */
-	m->base.from = TREE_TYPE (var);
+	   underlying decl. 
+
+	   Check gimple_can_coalesce_p when changing this code.  */
+	m->base.from = (TYPE_CANONICAL (TREE_TYPE (var))
+			? TYPE_CANONICAL (TREE_TYPE (var))
+			: TREE_TYPE (var));
       /* If base variable hasn't been seen, set it up.  */
       slot = tree_to_index.find_slot (m, INSERT);
       if (!*slot)
diff --git a/gcc/tree-ssa-uncprop.c b/gcc/tree-ssa-uncprop.c
index 1fbc524..555485a 100644
--- a/gcc/tree-ssa-uncprop.c
+++ b/gcc/tree-ssa-uncprop.c
@@ -474,12 +474,11 @@ uncprop_into_successor_phis (basic_block bb)
 	  equiv_hash_elt an_equiv_elt;
 	  equiv_hash_elt **slot;
 
-	  /* If the argument is not an invariant, and refers to the same
-	     underlying variable as the PHI result, then there's no
-	     point in un-propagating the argument.  */
+	  /* If the argument is not an invariant and can be potentially
+	     coalesced with the result, then there's no point in
+	     un-propagating the argument.  */
 	  if (!is_gimple_min_invariant (arg)
-	      && (SSA_NAME_VAR (arg) == SSA_NAME_VAR (res)
-		  && TREE_TYPE (arg) == TREE_TYPE (res)))
+	      && gimple_can_coalesce_p (arg, res))
 	    continue;
 
 	  /* Lookup this argument's value in the hash table.  */
@@ -493,7 +492,7 @@ uncprop_into_successor_phis (basic_block bb)
 	      int j;
 
 	      /* Walk every equivalence with the same value.  If we find
-		 one with the same underlying variable as the PHI result,
+		 one that can potentially coalesce with the PHI rsult,
 		 then replace the value in the argument with its equivalent
 		 SSA_NAME.  Use the most recent equivalence as hopefully
 		 that results in shortest lifetimes.  */
@@ -501,8 +500,7 @@ uncprop_into_successor_phis (basic_block bb)
 		{
 		  tree equiv = elt->equivalences[j];
 
-		  if (SSA_NAME_VAR (equiv) == SSA_NAME_VAR (res)
-		      && TREE_TYPE (equiv) == TREE_TYPE (res))
+		  if (gimple_can_coalesce_p (equiv, res))
 		    {
 		      SET_PHI_ARG_DEF (phi, e->dest_idx, equiv);
 		      break;