gimple.c (gimple_replace_lhs): Move to tree-ssa.c and rename.

2013-09-26  Andrew MacLeod <amacleod@redhat.com>

	* gimple.c (gimple_replace_lhs): Move to tree-ssa.c and rename.
	(struct count_ptr_d, count_ptr_derefs, count_uses_and_derefs): Move to
	tree-ssa.c
	(create_gimple_tmp): Delete.
	(get_expr_type, build_assign, build_type_cast): Move to...
	* gimple-builder.c: New File.
	(get_expr_type): Relocate from gimple.c.
	(build_assign, build_type_cast): Change to only create ssanames.
	* gimple.h: Move prototypes to...
	* gimple-builder.h: New File. Here.
	* tree-ssa.h: And here.
	* tree-ssa.c (struct count_ptr_d, count_ptr_derefs,
	count_uses_and_derefs): Relocate from gimple.c.
	(gimple_replace_ssa_lhs): Renamed gimple_replace_ssa from gimple.c
	* tree-ssa-reassoc.c (repropagate_negates): Use gimple_replace_ssa_lhs.
	* tree-ssa-math-opts (execute_cse_reciprocals): Use
	gimple_replace_ssa_lhs.
	* asan.c: Include gimple-builder.h.
	* Makefile.in: Add gimple-builder.o.

From-SVN: r202945

1 files changed, 129 insertions, 0 deletions

diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index 8146e1f..8c340de 100644
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -231,6 +231,135 @@ flush_pending_stmts (edge e)
   redirect_edge_var_map_clear (e);
 }
 
+
+/* Data structure used to count the number of dereferences to PTR
+   inside an expression.  */
+struct count_ptr_d
+{
+  tree ptr;
+  unsigned num_stores;
+  unsigned num_loads;
+};
+
+
+/* Helper for count_uses_and_derefs.  Called by walk_tree to look for
+   (ALIGN/MISALIGNED_)INDIRECT_REF nodes for the pointer passed in DATA.  */
+
+static tree
+count_ptr_derefs (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi_p = (struct walk_stmt_info *) data;
+  struct count_ptr_d *count_p = (struct count_ptr_d *) wi_p->info;
+
+  /* Do not walk inside ADDR_EXPR nodes.  In the expression &ptr->fld,
+     pointer 'ptr' is *not* dereferenced, it is simply used to compute
+     the address of 'fld' as 'ptr + offsetof(fld)'.  */
+  if (TREE_CODE (*tp) == ADDR_EXPR)
+    {
+      *walk_subtrees = 0;
+      return NULL_TREE;
+    }
+
+  if (TREE_CODE (*tp) == MEM_REF && TREE_OPERAND (*tp, 0) == count_p->ptr)
+    {
+      if (wi_p->is_lhs)
+	count_p->num_stores++;
+      else
+	count_p->num_loads++;
+    }
+
+  return NULL_TREE;
+}
+
+
+/* Count the number of direct and indirect uses for pointer PTR in
+   statement STMT.  The number of direct uses is stored in
+   *NUM_USES_P.  Indirect references are counted separately depending
+   on whether they are store or load operations.  The counts are
+   stored in *NUM_STORES_P and *NUM_LOADS_P.  */
+
+void
+count_uses_and_derefs (tree ptr, gimple stmt, unsigned *num_uses_p,
+		       unsigned *num_loads_p, unsigned *num_stores_p)
+{
+  ssa_op_iter i;
+  tree use;
+
+  *num_uses_p = 0;
+  *num_loads_p = 0;
+  *num_stores_p = 0;
+
+  /* Find out the total number of uses of PTR in STMT.  */
+  FOR_EACH_SSA_TREE_OPERAND (use, stmt, i, SSA_OP_USE)
+    if (use == ptr)
+      (*num_uses_p)++;
+
+  /* Now count the number of indirect references to PTR.  This is
+     truly awful, but we don't have much choice.  There are no parent
+     pointers inside INDIRECT_REFs, so an expression like
+     '*x_1 = foo (x_1, *x_1)' needs to be traversed piece by piece to
+     find all the indirect and direct uses of x_1 inside.  The only
+     shortcut we can take is the fact that GIMPLE only allows
+     INDIRECT_REFs inside the expressions below.  */
+  if (is_gimple_assign (stmt)
+      || gimple_code (stmt) == GIMPLE_RETURN
+      || gimple_code (stmt) == GIMPLE_ASM
+      || is_gimple_call (stmt))
+    {
+      struct walk_stmt_info wi;
+      struct count_ptr_d count;
+
+      count.ptr = ptr;
+      count.num_stores = 0;
+      count.num_loads = 0;
+
+      memset (&wi, 0, sizeof (wi));
+      wi.info = &count;
+      walk_gimple_op (stmt, count_ptr_derefs, &wi);
+
+      *num_stores_p = count.num_stores;
+      *num_loads_p = count.num_loads;
+    }
+
+  gcc_assert (*num_uses_p >= *num_loads_p + *num_stores_p);
+}
+
+
+/* Replace the LHS of STMT, an assignment, either a GIMPLE_ASSIGN or a
+   GIMPLE_CALL, with NLHS, in preparation for modifying the RHS to an
+   expression with a different value.
+
+   This will update any annotations (say debug bind stmts) referring
+   to the original LHS, so that they use the RHS instead.  This is
+   done even if NLHS and LHS are the same, for it is understood that
+   the RHS will be modified afterwards, and NLHS will not be assigned
+   an equivalent value.
+
+   Adjusting any non-annotation uses of the LHS, if needed, is a
+   responsibility of the caller.
+
+   The effect of this call should be pretty much the same as that of
+   inserting a copy of STMT before STMT, and then removing the
+   original stmt, at which time gsi_remove() would have update
+   annotations, but using this function saves all the inserting,
+   copying and removing.  */
+
+void
+gimple_replace_ssa_lhs (gimple stmt, tree nlhs)
+{
+  if (MAY_HAVE_DEBUG_STMTS)
+    {
+      tree lhs = gimple_get_lhs (stmt);
+
+      gcc_assert (SSA_NAME_DEF_STMT (lhs) == stmt);
+
+      insert_debug_temp_for_var_def (NULL, lhs);
+    }
+
+  gimple_set_lhs (stmt, nlhs);
+}
+
+
 /* Given a tree for an expression for which we might want to emit
    locations or values in debug information (generally a variable, but
    we might deal with other kinds of trees in the future), return the