static tree
get_real_ref_rhs (tree expr)
{
switch (TREE_CODE (expr))
{
case SSA_NAME:
{
/* Given a self-assign statement, say foo.x = foo.x,
the IR (after SSA) looks like:
D.1797_14 = foo.x;
foo.x ={v} D.1797_14;
So if the rhs EXPR is an SSA_NAME of a temp variable,
e.g. D.1797_14, we need to grab the rhs of its SSA def
statement (i.e. foo.x). */
tree vdecl = SSA_NAME_VAR (expr);
if ((!vdecl || DECL_ARTIFICIAL (vdecl))
&& !gimple_nop_p (SSA_NAME_DEF_STMT (expr)))
{
gimple def_stmt = SSA_NAME_DEF_STMT (expr);
/* We are only interested in an assignment with a single
rhs operand because if it is not, the original assignment
will not possibly be a self-assignment. */
if (gimple_assign_single_p (def_stmt))
return get_real_ref_rhs (gimple_assign_rhs1 (def_stmt));
else
return NULL_TREE;
}
else
return vdecl;
}
case VAR_DECL:
case PARM_DECL:
case FIELD_DECL:
case COMPONENT_REF:
case MEM_REF:
case ARRAY_REF:
return expr;
default:
return NULL_TREE;
}
}
static tree
get_non_ssa_expr (tree expr)
{
if (!expr)
return NULL_TREE;
switch (TREE_CODE (expr))
{
case VAR_DECL:
case PARM_DECL:
case FIELD_DECL:
{
if (DECL_NAME (expr))
return expr;
else
return NULL_TREE;
}
case COMPONENT_REF:
{
tree base, orig_base = TREE_OPERAND (expr, 0);
tree component, orig_component = TREE_OPERAND (expr, 1);
base = get_non_ssa_expr (orig_base);
if (!base)
return NULL_TREE;
component = get_non_ssa_expr (orig_component);
if (!component)
return NULL_TREE;
/* If either BASE or COMPONENT is converted, build a new
component reference tree. */
if (base != orig_base || component != orig_component)
return build3 (COMPONENT_REF, TREE_TYPE (component),
base, component, NULL_TREE);
else
return expr;
}
case MEM_REF:
{
tree orig_base = TREE_OPERAND (expr, 0);
if (TREE_CODE (orig_base) == SSA_NAME)
{
tree base = get_non_ssa_expr (orig_base);
if (!base)
return NULL_TREE;
return fold_build2 (MEM_REF, TREE_TYPE (expr),
base, TREE_OPERAND (expr, 1));
}
return expr;
}
case ARRAY_REF:
{
tree array, orig_array = TREE_OPERAND (expr, 0);
tree index, orig_index = TREE_OPERAND (expr, 1);
array = get_non_ssa_expr (orig_array);
if (!array)
return NULL_TREE;
index = get_non_ssa_expr (orig_index);
if (!index)
return NULL_TREE;
/* If either ARRAY or INDEX is converted, build a new array
reference tree. */
if (array != orig_array || index != orig_index)
return build4 (ARRAY_REF, TREE_TYPE (expr), array, index,
TREE_OPERAND (expr, 2), TREE_OPERAND (expr, 3));
else
return expr;
}
case SSA_NAME:
{
tree vdecl = SSA_NAME_VAR (expr);
if ((!vdecl || DECL_ARTIFICIAL (vdecl))
&& !gimple_nop_p (SSA_NAME_DEF_STMT (expr)))
{
gimple def_stmt = SSA_NAME_DEF_STMT (expr);
if (gimple_assign_single_p (def_stmt))
vdecl = gimple_assign_rhs1 (def_stmt);
}
return get_non_ssa_expr (vdecl);
}
case INTEGER_CST:
return expr;
default:
/* Return NULL_TREE for any other kind of tree nodes. */
return NULL_TREE;
}
}
