/* Conditional constant propagation pass for the GNU compiler.
- Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org>
Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com>
#include "langhooks.h"
#include "target.h"
#include "toplev.h"
+#include "dbgcnt.h"
/* Possible lattice values. */
doing the store). */
static prop_value_t *const_val;
+static void canonicalize_float_value (prop_value_t *);
+
/* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */
static void
get_symbol_constant_value (tree sym)
{
if (TREE_STATIC (sym)
- && TREE_READONLY (sym)
- && !MTAG_P (sym))
+ && TREE_READONLY (sym))
{
tree val = DECL_INITIAL (sym);
if (val)
{
STRIP_USELESS_TYPE_CONVERSION (val);
if (is_gimple_min_invariant (val))
- return val;
+ {
+ if (TREE_CODE (val) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (val, 0));
+ if (base && TREE_CODE (base) == VAR_DECL)
+ add_referenced_var (base);
+ }
+ return val;
+ }
}
/* Variables declared 'const' without an initializer
have zero as the initializer if they may not be
overridden at link or run time. */
if (!val
+ && !DECL_EXTERNAL (sym)
&& targetm.binds_local_p (sym)
&& (INTEGRAL_TYPE_P (TREE_TYPE (sym))
|| SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym))))
- return fold_convert (TREE_TYPE (sym), integer_zero_node);
+ return fold_convert (TREE_TYPE (sym), integer_zero_node);
}
return NULL_TREE;
{
tree sym = SSA_NAME_VAR (var);
prop_value_t val = { UNINITIALIZED, NULL_TREE };
- tree cst_val;
-
- if (!is_gimple_reg (var))
- {
- /* Short circuit for regular CCP. We are not interested in any
- non-register when DO_STORE_CCP is false. */
- val.lattice_val = VARYING;
- }
- else if ((cst_val = get_symbol_constant_value (sym)) != NULL_TREE)
+ gimple stmt;
+
+ stmt = SSA_NAME_DEF_STMT (var);
+
+ if (gimple_nop_p (stmt))
{
- /* Globals and static variables declared 'const' take their
- initial value. */
- val.lattice_val = CONSTANT;
- val.value = cst_val;
+ /* Variables defined by an empty statement are those used
+ before being initialized. If VAR is a local variable, we
+ can assume initially that it is UNDEFINED, otherwise we must
+ consider it VARYING. */
+ if (is_gimple_reg (sym) && TREE_CODE (sym) != PARM_DECL)
+ val.lattice_val = UNDEFINED;
+ else
+ val.lattice_val = VARYING;
}
- else
- {
- gimple stmt = SSA_NAME_DEF_STMT (var);
-
- if (gimple_nop_p (stmt))
+ else if (is_gimple_assign (stmt)
+ /* Value-returning GIMPLE_CALL statements assign to
+ a variable, and are treated similarly to GIMPLE_ASSIGN. */
+ || (is_gimple_call (stmt)
+ && gimple_call_lhs (stmt) != NULL_TREE)
+ || gimple_code (stmt) == GIMPLE_PHI)
+ {
+ tree cst;
+ if (gimple_assign_single_p (stmt)
+ && DECL_P (gimple_assign_rhs1 (stmt))
+ && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt))))
{
- /* Variables defined by an empty statement are those used
- before being initialized. If VAR is a local variable, we
- can assume initially that it is UNDEFINED, otherwise we must
- consider it VARYING. */
- if (is_gimple_reg (sym) && TREE_CODE (sym) != PARM_DECL)
- val.lattice_val = UNDEFINED;
- else
- val.lattice_val = VARYING;
- }
- else if (is_gimple_assign (stmt)
- /* Value-returning GIMPLE_CALL statements assign to
- a variable, and are treated similarly to GIMPLE_ASSIGN. */
- || (is_gimple_call (stmt)
- && gimple_call_lhs (stmt) != NULL_TREE)
- || gimple_code (stmt) == GIMPLE_PHI)
- {
- /* Any other variable defined by an assignment or a PHI node
- is considered UNDEFINED. */
- val.lattice_val = UNDEFINED;
+ val.lattice_val = CONSTANT;
+ val.value = cst;
}
else
- {
- /* Otherwise, VAR will never take on a constant value. */
- val.lattice_val = VARYING;
- }
+ /* Any other variable defined by an assignment or a PHI node
+ is considered UNDEFINED. */
+ val.lattice_val = UNDEFINED;
+ }
+ else
+ {
+ /* Otherwise, VAR will never take on a constant value. */
+ val.lattice_val = VARYING;
}
return val;
if (val->lattice_val == UNINITIALIZED)
*val = get_default_value (var);
+ canonicalize_float_value (val);
+
return val;
}
bool has_constant_operand, has_undefined_operand, all_undefined_operands;
tree use;
ssa_op_iter iter;
+ unsigned i;
enum gimple_code code = gimple_code (stmt);
if (gimple_has_volatile_ops (stmt))
return VARYING;
- /* If we are not doing store-ccp, statements with loads
- and/or stores will never fold into a constant. */
- if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
- return VARYING;
-
- /* Note that only a GIMPLE_SINGLE_RHS assignment can satisfy
- is_gimple_min_invariant, so we do not consider calls or
- other forms of assignment. */
- if (gimple_assign_single_p (stmt)
- && is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
- return CONSTANT;
-
- if (code == GIMPLE_COND
- && is_gimple_min_invariant (gimple_cond_lhs (stmt))
- && is_gimple_min_invariant (gimple_cond_rhs (stmt)))
- return CONSTANT;
-
- if (code == GIMPLE_SWITCH
- && is_gimple_min_invariant (gimple_switch_index (stmt)))
- return CONSTANT;
-
/* Arrive here for more complex cases. */
-
has_constant_operand = false;
has_undefined_operand = false;
all_undefined_operands = true;
- FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE | SSA_OP_VUSE)
+ FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
{
prop_value_t *val = get_value (use);
has_constant_operand = true;
}
+ /* There may be constants in regular rhs operands. For calls we
+ have to ignore lhs, fndecl and static chain, otherwise only
+ the lhs. */
+ for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt);
+ i < gimple_num_ops (stmt); ++i)
+ {
+ tree op = gimple_op (stmt, i);
+ if (!op || TREE_CODE (op) == SSA_NAME)
+ continue;
+ if (is_gimple_min_invariant (op))
+ has_constant_operand = true;
+ }
+
/* If the operation combines operands like COMPLEX_EXPR make sure to
not mark the result UNDEFINED if only one part of the result is
undefined. */
if (has_undefined_operand)
return VARYING;
+ /* We do not consider virtual operands here -- load from read-only
+ memory may have only VARYING virtual operands, but still be
+ constant. */
if (has_constant_operand
- /* We do not consider virtual operands here -- load from read-only
- memory may have only VARYING virtual operands, but still be
- constant. */
- || ZERO_SSA_OPERANDS (stmt, SSA_OP_USE))
+ || gimple_references_memory_p (stmt))
return CONSTANT;
return VARYING;
if (gimple_has_volatile_ops (stmt))
return true;
- if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
- return true;
-
/* If it is a call and does not return a value or is not a
builtin and not an indirect call, it is varying. */
if (is_gimple_call (stmt))
return true;
}
+ /* Any other store operation is not interesting. */
+ else if (gimple_vdef (stmt))
+ return true;
+
/* Anything other than assignments and conditional jumps are not
interesting for CCP. */
if (gimple_code (stmt) != GIMPLE_ASSIGN
/* If the statement will not produce a constant, mark
all its outputs VARYING. */
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS)
- {
- if (is_varying)
- set_value_varying (def);
- }
+ set_value_varying (def);
}
prop_set_simulate_again (stmt, !is_varying);
}
}
}
+/* Debug count support. Reset the values of ssa names
+ VARYING when the total number ssa names analyzed is
+ beyond the debug count specified. */
+
+static void
+do_dbg_cnt (void)
+{
+ unsigned i;
+ for (i = 0; i < num_ssa_names; i++)
+ {
+ if (!dbg_cnt (ccp))
+ {
+ const_val[i].lattice_val = VARYING;
+ const_val[i].value = NULL_TREE;
+ }
+ }
+}
+
/* Do final substitution of propagated values, cleanup the flowgraph and
free allocated storage.
static bool
ccp_finalize (void)
{
+ bool something_changed;
+
+ do_dbg_cnt ();
/* Perform substitutions based on the known constant values. */
- bool something_changed = substitute_and_fold (const_val, false);
+ something_changed = substitute_and_fold (const_val, false);
free (const_val);
const_val = NULL;
return SSA_PROP_NOT_INTERESTING;
}
+/* Return true if we may propagate the address expression ADDR into the
+ dereference DEREF and cancel them. */
+
+bool
+may_propagate_address_into_dereference (tree addr, tree deref)
+{
+ gcc_assert (INDIRECT_REF_P (deref)
+ && TREE_CODE (addr) == ADDR_EXPR);
+
+ /* Don't propagate if ADDR's operand has incomplete type. */
+ if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_OPERAND (addr, 0))))
+ return false;
+
+ /* If the address is invariant then we do not need to preserve restrict
+ qualifications. But we do need to preserve volatile qualifiers until
+ we can annotate the folded dereference itself properly. */
+ if (is_gimple_min_invariant (addr)
+ && (!TREE_THIS_VOLATILE (deref)
+ || TYPE_VOLATILE (TREE_TYPE (addr))))
+ return useless_type_conversion_p (TREE_TYPE (deref),
+ TREE_TYPE (TREE_OPERAND (addr, 0)));
+
+ /* Else both the address substitution and the folding must result in
+ a valid useless type conversion sequence. */
+ return (useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (deref, 0)),
+ TREE_TYPE (addr))
+ && useless_type_conversion_p (TREE_TYPE (deref),
+ TREE_TYPE (TREE_OPERAND (addr, 0))));
+}
/* CCP specific front-end to the non-destructive constant folding
routines.
prop_value_t *val = get_value (TREE_OPERAND (*base, 0));
if (val->lattice_val == CONSTANT
&& TREE_CODE (val->value) == ADDR_EXPR
- && useless_type_conversion_p
- (TREE_TYPE (TREE_OPERAND (*base, 0)),
- TREE_TYPE (val->value))
- && useless_type_conversion_p
- (TREE_TYPE (*base),
- TREE_TYPE (TREE_OPERAND (val->value, 0))))
+ && may_propagate_address_into_dereference
+ (val->value, *base))
{
/* We need to return a new tree, not modify the IL
or share parts of it. So play some tricks to
}
}
}
+ else if (TREE_CODE (rhs) == CONSTRUCTOR
+ && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE
+ && (CONSTRUCTOR_NELTS (rhs)
+ == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))))
+ {
+ unsigned i;
+ tree val, list;
+
+ list = NULL_TREE;
+ FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val)
+ {
+ if (TREE_CODE (val) == SSA_NAME
+ && get_value (val)->lattice_val == CONSTANT)
+ val = get_value (val)->value;
+ if (TREE_CODE (val) == INTEGER_CST
+ || TREE_CODE (val) == REAL_CST
+ || TREE_CODE (val) == FIXED_CST)
+ list = tree_cons (NULL_TREE, val, list);
+ else
+ return NULL_TREE;
+ }
+
+ return build_vector (TREE_TYPE (rhs), nreverse (list));
+ }
if (kind == tcc_reference)
{
- if (TREE_CODE (rhs) == VIEW_CONVERT_EXPR
+ if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR
+ || TREE_CODE (rhs) == REALPART_EXPR
+ || TREE_CODE (rhs) == IMAGPART_EXPR)
&& TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
{
prop_value_t *val = get_value (TREE_OPERAND (rhs, 0));
if (val->lattice_val == CONSTANT)
- return fold_unary (VIEW_CONVERT_EXPR,
+ return fold_unary (TREE_CODE (rhs),
TREE_TYPE (rhs), val->value);
}
+ else if (TREE_CODE (rhs) == INDIRECT_REF
+ && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
+ {
+ prop_value_t *val = get_value (TREE_OPERAND (rhs, 0));
+ if (val->lattice_val == CONSTANT
+ && TREE_CODE (val->value) == ADDR_EXPR
+ && useless_type_conversion_p (TREE_TYPE (rhs),
+ TREE_TYPE (TREE_TYPE (val->value))))
+ rhs = TREE_OPERAND (val->value, 0);
+ }
return fold_const_aggregate_ref (rhs);
}
else if (kind == tcc_declaration)
so this should almost always return a simplified RHS. */
tree lhs = gimple_assign_lhs (stmt);
tree op0 = gimple_assign_rhs1 (stmt);
- tree res;
/* Simplify the operand down to a constant. */
if (TREE_CODE (op0) == SSA_NAME)
return op0;
}
- res = fold_unary (subcode, gimple_expr_type (stmt), op0);
-
- /* If the operation was a conversion do _not_ mark a
- resulting constant with TREE_OVERFLOW if the original
- constant was not. These conversions have implementation
- defined behavior and retaining the TREE_OVERFLOW flag
- here would confuse later passes such as VRP. */
- if (res
- && TREE_CODE (res) == INTEGER_CST
- && TREE_CODE (op0) == INTEGER_CST
- && CONVERT_EXPR_CODE_P (subcode))
- TREE_OVERFLOW (res) = TREE_OVERFLOW (op0);
-
- return res;
+ return fold_unary_ignore_overflow (subcode,
+ gimple_expr_type (stmt), op0);
}
case GIMPLE_BINARY_RHS:
unsigned HOST_WIDE_INT cnt;
tree cfield, cval;
+ if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration)
+ return get_symbol_constant_value (t);
+
switch (TREE_CODE (t))
{
case ARRAY_REF:
if (tree_int_cst_equal (cfield, idx))
{
STRIP_USELESS_TYPE_CONVERSION (cval);
+ if (TREE_CODE (cval) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (cval, 0));
+ if (base && TREE_CODE (base) == VAR_DECL)
+ add_referenced_var (base);
+ }
return cval;
}
break;
&& ! DECL_BIT_FIELD (cfield))
{
STRIP_USELESS_TYPE_CONVERSION (cval);
+ if (TREE_CODE (cval) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (cval, 0));
+ if (base && TREE_CODE (base) == VAR_DECL)
+ add_referenced_var (base);
+ }
return cval;
}
break;
if (TREE_CODE (base) == SSA_NAME
&& (value = get_value (base))
&& value->lattice_val == CONSTANT
- && TREE_CODE (value->value) == ADDR_EXPR)
+ && TREE_CODE (value->value) == ADDR_EXPR
+ && useless_type_conversion_p (TREE_TYPE (t),
+ TREE_TYPE (TREE_TYPE (value->value))))
return fold_const_aggregate_ref (TREE_OPERAND (value->value, 0));
break;
}
};
-/* A subroutine of fold_stmt_r. Attempts to fold *(A+O) to A[X].
+/* A subroutine of fold_stmt. Attempts to fold *(A+O) to A[X].
BASE is an array type. OFFSET is a byte displacement. ORIG_TYPE
is the desired result type. */
|| (TREE_CODE (orig) == COMPONENT_REF
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (orig, 1))) == ARRAY_TYPE))
&& (TREE_CODE (t) == ARRAY_REF
- || (TREE_CODE (t) == COMPONENT_REF
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 1))) == ARRAY_TYPE))
+ || TREE_CODE (t) == COMPONENT_REF)
&& !operand_equal_p (TREE_CODE (orig) == ARRAY_REF
? TREE_OPERAND (orig, 0) : orig,
TREE_CODE (t) == ARRAY_REF
return NULL_TREE;
}
-/* A subroutine of fold_stmt_r. Attempt to simplify *(BASE+OFFSET).
+/* A subroutine of fold_stmt. Attempt to simplify *(BASE+OFFSET).
Return the simplified expression, or NULL if nothing could be done. */
static tree
tree ptd_type;
tree t;
- /* It had better be a constant. */
- if (TREE_CODE (op1) != INTEGER_CST)
- return NULL_TREE;
/* The first operand should be an ADDR_EXPR. */
if (TREE_CODE (op0) != ADDR_EXPR)
return NULL_TREE;
op0 = TREE_OPERAND (op0, 0);
+ /* It had better be a constant. */
+ if (TREE_CODE (op1) != INTEGER_CST)
+ {
+ /* Or op0 should now be A[0] and the non-constant offset defined
+ via a multiplication by the array element size. */
+ if (TREE_CODE (op0) == ARRAY_REF
+ && integer_zerop (TREE_OPERAND (op0, 1))
+ && TREE_CODE (op1) == SSA_NAME
+ && host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (op0)), 1))
+ {
+ gimple offset_def = SSA_NAME_DEF_STMT (op1);
+ if (!is_gimple_assign (offset_def))
+ return NULL_TREE;
+
+ if (gimple_assign_rhs_code (offset_def) == MULT_EXPR
+ && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def),
+ TYPE_SIZE_UNIT (TREE_TYPE (op0))))
+ return build1 (ADDR_EXPR, res_type,
+ build4 (ARRAY_REF, TREE_TYPE (op0),
+ TREE_OPERAND (op0, 0),
+ gimple_assign_rhs1 (offset_def),
+ TREE_OPERAND (op0, 2),
+ TREE_OPERAND (op0, 3)));
+ else if (integer_onep (TYPE_SIZE_UNIT (TREE_TYPE (op0)))
+ && gimple_assign_rhs_code (offset_def) != MULT_EXPR)
+ return build1 (ADDR_EXPR, res_type,
+ build4 (ARRAY_REF, TREE_TYPE (op0),
+ TREE_OPERAND (op0, 0),
+ op1,
+ TREE_OPERAND (op0, 2),
+ TREE_OPERAND (op0, 3)));
+ }
+ return NULL_TREE;
+ }
+
/* If the first operand is an ARRAY_REF, expand it so that we can fold
the offset into it. */
while (TREE_CODE (op0) == ARRAY_REF)
return t;
}
-/* For passing state through walk_tree into fold_stmt_r and its
- children. */
-
-struct fold_stmt_r_data
-{
- gimple stmt;
- bool *changed_p;
- bool *inside_addr_expr_p;
-};
-
-/* Subroutine of fold_stmt called via walk_tree. We perform several
- simplifications of EXPR_P, mostly having to do with pointer arithmetic. */
+/* Subroutine of fold_stmt. We perform several simplifications of the
+ memory reference tree EXPR and make sure to re-gimplify them properly
+ after propagation of constant addresses. IS_LHS is true if the
+ reference is supposed to be an lvalue. */
static tree
-fold_stmt_r (tree *expr_p, int *walk_subtrees, void *data)
+maybe_fold_reference (tree expr, bool is_lhs)
{
- struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
- struct fold_stmt_r_data *fold_stmt_r_data;
- bool *inside_addr_expr_p;
- bool *changed_p;
- tree expr = *expr_p, t;
- bool volatile_p = TREE_THIS_VOLATILE (expr);
+ tree *t = &expr;
- fold_stmt_r_data = (struct fold_stmt_r_data *) wi->info;
- inside_addr_expr_p = fold_stmt_r_data->inside_addr_expr_p;
- changed_p = fold_stmt_r_data->changed_p;
+ if (TREE_CODE (expr) == ARRAY_REF
+ && !is_lhs)
+ {
+ tree tem = fold_read_from_constant_string (expr);
+ if (tem)
+ return tem;
+ }
- /* ??? It'd be nice if walk_tree had a pre-order option. */
- switch (TREE_CODE (expr))
+ /* ??? We might want to open-code the relevant remaining cases
+ to avoid using the generic fold. */
+ if (handled_component_p (*t)
+ && CONSTANT_CLASS_P (TREE_OPERAND (*t, 0)))
{
- case INDIRECT_REF:
- t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL);
- if (t)
- return t;
- *walk_subtrees = 0;
+ tree tem = fold (*t);
+ if (tem != *t)
+ return tem;
+ }
+
+ while (handled_component_p (*t))
+ t = &TREE_OPERAND (*t, 0);
- t = maybe_fold_stmt_indirect (expr, TREE_OPERAND (expr, 0),
- integer_zero_node);
- if (!t
- && TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR)
+ if (TREE_CODE (*t) == INDIRECT_REF)
+ {
+ tree tem = maybe_fold_stmt_indirect (*t, TREE_OPERAND (*t, 0),
+ integer_zero_node);
+ /* Avoid folding *"abc" = 5 into 'a' = 5. */
+ if (is_lhs && tem && CONSTANT_CLASS_P (tem))
+ tem = NULL_TREE;
+ if (!tem
+ && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR)
/* If we had a good reason for propagating the address here,
make sure we end up with valid gimple. See PR34989. */
- t = TREE_OPERAND (TREE_OPERAND (expr, 0), 0);
- break;
-
- case NOP_EXPR:
- t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL);
- if (t)
- return t;
- *walk_subtrees = 0;
-
- if (POINTER_TYPE_P (TREE_TYPE (expr))
- && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (expr)))
- && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 0)))
- && (t = maybe_fold_offset_to_address (TREE_OPERAND (expr, 0),
- integer_zero_node,
- TREE_TYPE (TREE_TYPE (expr)))))
- return t;
- break;
+ tem = TREE_OPERAND (TREE_OPERAND (*t, 0), 0);
- /* ??? Could handle more ARRAY_REFs here, as a variant of INDIRECT_REF.
- We'd only want to bother decomposing an existing ARRAY_REF if
- the base array is found to have another offset contained within.
- Otherwise we'd be wasting time. */
- case ARRAY_REF:
- /* If we are not processing expressions found within an
- ADDR_EXPR, then we can fold constant array references. */
- if (!*inside_addr_expr_p)
- t = fold_read_from_constant_string (expr);
- else
- t = NULL;
- break;
-
- case ADDR_EXPR:
- *inside_addr_expr_p = true;
- t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL);
- *inside_addr_expr_p = false;
- if (t)
- return t;
- *walk_subtrees = 0;
-
- /* Make sure the value is properly considered constant, and so gets
- propagated as expected. */
- if (*changed_p)
- recompute_tree_invariant_for_addr_expr (expr);
- return NULL_TREE;
-
- case COMPONENT_REF:
- t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL);
- if (t)
- return t;
- *walk_subtrees = 0;
-
- /* Make sure the FIELD_DECL is actually a field in the type on the lhs.
- We've already checked that the records are compatible, so we should
- come up with a set of compatible fields. */
- {
- tree expr_record = TREE_TYPE (TREE_OPERAND (expr, 0));
- tree expr_field = TREE_OPERAND (expr, 1);
-
- if (DECL_FIELD_CONTEXT (expr_field) != TYPE_MAIN_VARIANT (expr_record))
- {
- expr_field = find_compatible_field (expr_record, expr_field);
- TREE_OPERAND (expr, 1) = expr_field;
- }
- }
- break;
-
- case TARGET_MEM_REF:
- t = maybe_fold_tmr (expr);
- break;
-
- case POINTER_PLUS_EXPR:
- t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL);
- if (t)
- return t;
- t = walk_tree (&TREE_OPERAND (expr, 1), fold_stmt_r, data, NULL);
- if (t)
- return t;
- *walk_subtrees = 0;
-
- t = maybe_fold_stmt_addition (TREE_TYPE (expr),
- TREE_OPERAND (expr, 0),
- TREE_OPERAND (expr, 1));
- break;
-
- case COND_EXPR:
- if (COMPARISON_CLASS_P (TREE_OPERAND (expr, 0)))
- {
- tree op0 = TREE_OPERAND (expr, 0);
- tree tem;
- bool set;
-
- fold_defer_overflow_warnings ();
- tem = fold_binary (TREE_CODE (op0), TREE_TYPE (op0),
- TREE_OPERAND (op0, 0),
- TREE_OPERAND (op0, 1));
- /* This is actually a conditional expression, not a GIMPLE
- conditional statement, however, the valid_gimple_rhs_p
- test still applies. */
- set = tem && is_gimple_condexpr (tem) && valid_gimple_rhs_p (tem);
- fold_undefer_overflow_warnings (set, fold_stmt_r_data->stmt, 0);
- if (set)
- {
- COND_EXPR_COND (expr) = tem;
- t = expr;
- break;
- }
- }
- return NULL_TREE;
-
- default:
- return NULL_TREE;
- }
-
- if (t)
- {
- /* Preserve volatileness of the original expression.
- We can end up with a plain decl here which is shared
- and we shouldn't mess with its flags. */
- if (!SSA_VAR_P (t))
- TREE_THIS_VOLATILE (t) = volatile_p;
- *expr_p = t;
- *changed_p = true;
+ if (tem)
+ {
+ *t = tem;
+ tem = maybe_fold_reference (expr, is_lhs);
+ if (tem)
+ return tem;
+ return expr;
+ }
}
return NULL_TREE;
}
+
/* Return the string length, maximum string length or maximum value of
ARG in LENGTH.
If ARG is an SSA name variable, follow its use-def chains. If LENGTH
return NULL_TREE;
}
+ if (arg_idx >= nargs)
+ return NULL_TREE;
+
/* Try to use the dataflow information gathered by the CCP process. */
visited = BITMAP_ALLOC (NULL);
bitmap_clear (visited);
switch (DECL_FUNCTION_CODE (callee))
{
case BUILT_IN_STRLEN:
- if (val[0])
+ if (val[0] && nargs == 1)
{
tree new_val =
fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]);
break;
case BUILT_IN_FPUTS:
- result = fold_builtin_fputs (gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- ignore, false, val[0]);
+ if (nargs == 2)
+ result = fold_builtin_fputs (gimple_call_arg (stmt, 0),
+ gimple_call_arg (stmt, 1),
+ ignore, false, val[0]);
break;
case BUILT_IN_FPUTS_UNLOCKED:
- result = fold_builtin_fputs (gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- ignore, true, val[0]);
+ if (nargs == 2)
+ result = fold_builtin_fputs (gimple_call_arg (stmt, 0),
+ gimple_call_arg (stmt, 1),
+ ignore, true, val[0]);
break;
case BUILT_IN_MEMCPY_CHK:
case BUILT_IN_MEMPCPY_CHK:
case BUILT_IN_MEMMOVE_CHK:
case BUILT_IN_MEMSET_CHK:
- if (val[2] && is_gimple_val (val[2]))
+ if (val[2] && is_gimple_val (val[2]) && nargs == 4)
result = fold_builtin_memory_chk (callee,
gimple_call_arg (stmt, 0),
gimple_call_arg (stmt, 1),
case BUILT_IN_STRCPY_CHK:
case BUILT_IN_STPCPY_CHK:
- if (val[1] && is_gimple_val (val[1]))
+ if (val[1] && is_gimple_val (val[1]) && nargs == 3)
result = fold_builtin_stxcpy_chk (callee,
gimple_call_arg (stmt, 0),
gimple_call_arg (stmt, 1),
break;
case BUILT_IN_STRNCPY_CHK:
- if (val[2] && is_gimple_val (val[2]))
+ if (val[2] && is_gimple_val (val[2]) && nargs == 4)
result = fold_builtin_strncpy_chk (gimple_call_arg (stmt, 0),
gimple_call_arg (stmt, 1),
gimple_call_arg (stmt, 2),
gimple stmt = gsi_stmt (*si);
enum tree_code subcode = gimple_assign_rhs_code (stmt);
- tree result = NULL;
+ tree result = NULL_TREE;
switch (get_gimple_rhs_class (subcode))
{
case GIMPLE_SINGLE_RHS:
{
tree rhs = gimple_assign_rhs1 (stmt);
-
+
/* Try to fold a conditional expression. */
if (TREE_CODE (rhs) == COND_EXPR)
{
- tree temp = fold (COND_EXPR_COND (rhs));
- if (temp != COND_EXPR_COND (rhs))
- result = fold_build3 (COND_EXPR, TREE_TYPE (rhs), temp,
- COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs));
+ tree op0 = COND_EXPR_COND (rhs);
+ tree tem;
+ bool set = false;
+
+ if (COMPARISON_CLASS_P (op0))
+ {
+ fold_defer_overflow_warnings ();
+ tem = fold_binary (TREE_CODE (op0), TREE_TYPE (op0),
+ TREE_OPERAND (op0, 0),
+ TREE_OPERAND (op0, 1));
+ /* This is actually a conditional expression, not a GIMPLE
+ conditional statement, however, the valid_gimple_rhs_p
+ test still applies. */
+ set = (tem && is_gimple_condexpr (tem)
+ && valid_gimple_rhs_p (tem));
+ fold_undefer_overflow_warnings (set, stmt, 0);
+ }
+ else if (is_gimple_min_invariant (op0))
+ {
+ tem = op0;
+ set = true;
+ }
+ else
+ return NULL_TREE;
+
+ if (set)
+ result = fold_build3 (COND_EXPR, TREE_TYPE (rhs), tem,
+ COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs));
}
+ else if (TREE_CODE (rhs) == TARGET_MEM_REF)
+ return maybe_fold_tmr (rhs);
+
+ else if (REFERENCE_CLASS_P (rhs))
+ return maybe_fold_reference (rhs, false);
+
+ else if (TREE_CODE (rhs) == ADDR_EXPR)
+ {
+ tree tem = maybe_fold_reference (TREE_OPERAND (rhs, 0), true);
+ if (tem)
+ result = fold_convert (TREE_TYPE (rhs),
+ build_fold_addr_expr (tem));
+ }
+
+ else if (TREE_CODE (rhs) == CONSTRUCTOR
+ && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE
+ && (CONSTRUCTOR_NELTS (rhs)
+ == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))))
+ {
+ /* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */
+ unsigned i;
+ tree val;
+
+ FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val)
+ if (TREE_CODE (val) != INTEGER_CST
+ && TREE_CODE (val) != REAL_CST
+ && TREE_CODE (val) != FIXED_CST)
+ return NULL_TREE;
+
+ return build_vector_from_ctor (TREE_TYPE (rhs),
+ CONSTRUCTOR_ELTS (rhs));
+ }
+
/* If we couldn't fold the RHS, hand over to the generic
fold routines. */
if (result == NULL_TREE)
if (result != rhs && valid_gimple_rhs_p (result))
return result;
- else
- /* It is possible that fold_stmt_r simplified the RHS.
- Make sure that the subcode of this statement still
- reflects the principal operator of the rhs operand. */
- return rhs;
+
+ return NULL_TREE;
}
break;
case GIMPLE_BINARY_RHS:
/* Try to fold pointer addition. */
if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
- result = maybe_fold_stmt_addition (
- TREE_TYPE (gimple_assign_lhs (stmt)),
- gimple_assign_rhs1 (stmt),
- gimple_assign_rhs2 (stmt));
+ {
+ tree type = TREE_TYPE (gimple_assign_rhs1 (stmt));
+ if (TREE_CODE (TREE_TYPE (type)) == ARRAY_TYPE)
+ {
+ type = build_pointer_type (TREE_TYPE (TREE_TYPE (type)));
+ if (!useless_type_conversion_p
+ (TREE_TYPE (gimple_assign_lhs (stmt)), type))
+ type = TREE_TYPE (gimple_assign_rhs1 (stmt));
+ }
+ result = maybe_fold_stmt_addition (type,
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt));
+ }
if (!result)
result = fold_binary (subcode,
return false;
}
-/* Fold the statement pointed to by GSI. In some cases, this function may
- replace the whole statement with a new one. Returns true iff folding
- makes any changes. */
+/* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument
+ distinguishes both cases. */
-bool
-fold_stmt (gimple_stmt_iterator *gsi)
+static bool
+fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace)
{
- tree res;
- struct fold_stmt_r_data fold_stmt_r_data;
- struct walk_stmt_info wi;
-
bool changed = false;
- bool inside_addr_expr = false;
-
gimple stmt = gsi_stmt (*gsi);
-
- fold_stmt_r_data.stmt = stmt;
- fold_stmt_r_data.changed_p = &changed;
- fold_stmt_r_data.inside_addr_expr_p = &inside_addr_expr;
-
- memset (&wi, 0, sizeof (wi));
- wi.info = &fold_stmt_r_data;
-
- /* Fold the individual operands.
- For example, fold instances of *&VAR into VAR, etc. */
- res = walk_gimple_op (stmt, fold_stmt_r, &wi);
- gcc_assert (!res);
+ unsigned i;
/* Fold the main computation performed by the statement. */
switch (gimple_code (stmt))
{
case GIMPLE_ASSIGN:
{
+ unsigned old_num_ops = gimple_num_ops (stmt);
tree new_rhs = fold_gimple_assign (gsi);
- if (new_rhs != NULL_TREE)
+ if (new_rhs != NULL_TREE
+ && (!inplace
+ || get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops))
{
gimple_assign_set_rhs_from_tree (gsi, new_rhs);
changed = true;
}
- stmt = gsi_stmt (*gsi);
break;
}
+
case GIMPLE_COND:
changed |= fold_gimple_cond (stmt);
break;
+
case GIMPLE_CALL:
+ /* Fold *& in call arguments. */
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
+ if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i)))
+ {
+ tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false);
+ if (tmp)
+ {
+ gimple_call_set_arg (stmt, i, tmp);
+ changed = true;
+ }
+ }
/* The entire statement may be replaced in this case. */
- changed |= fold_gimple_call (gsi);
+ if (!inplace)
+ changed |= fold_gimple_call (gsi);
break;
- default:
- return changed;
+ case GIMPLE_ASM:
+ /* Fold *& in asm operands. */
+ for (i = 0; i < gimple_asm_noutputs (stmt); ++i)
+ {
+ tree link = gimple_asm_output_op (stmt, i);
+ tree op = TREE_VALUE (link);
+ if (REFERENCE_CLASS_P (op)
+ && (op = maybe_fold_reference (op, true)) != NULL_TREE)
+ {
+ TREE_VALUE (link) = op;
+ changed = true;
+ }
+ }
+ for (i = 0; i < gimple_asm_ninputs (stmt); ++i)
+ {
+ tree link = gimple_asm_input_op (stmt, i);
+ tree op = TREE_VALUE (link);
+ if (REFERENCE_CLASS_P (op)
+ && (op = maybe_fold_reference (op, false)) != NULL_TREE)
+ {
+ TREE_VALUE (link) = op;
+ changed = true;
+ }
+ }
break;
+
+ default:;
+ }
+
+ stmt = gsi_stmt (*gsi);
+
+ /* Fold *& on the lhs. */
+ if (gimple_has_lhs (stmt))
+ {
+ tree lhs = gimple_get_lhs (stmt);
+ if (lhs && REFERENCE_CLASS_P (lhs))
+ {
+ tree new_lhs = maybe_fold_reference (lhs, true);
+ if (new_lhs)
+ {
+ gimple_set_lhs (stmt, new_lhs);
+ changed = true;
+ }
+ }
}
return changed;
}
+/* Fold the statement pointed to by GSI. In some cases, this function may
+ replace the whole statement with a new one. Returns true iff folding
+ makes any changes.
+ The statement pointed to by GSI should be in valid gimple form but may
+ be in unfolded state as resulting from for example constant propagation
+ which can produce *&x = 0. */
+
+bool
+fold_stmt (gimple_stmt_iterator *gsi)
+{
+ return fold_stmt_1 (gsi, false);
+}
+
/* Perform the minimal folding on statement STMT. Only operations like
*&x created by constant propagation are handled. The statement cannot
be replaced with a new one. Return true if the statement was
- changed, false otherwise. */
+ changed, false otherwise.
+ The statement STMT should be in valid gimple form but may
+ be in unfolded state as resulting from for example constant propagation
+ which can produce *&x = 0. */
bool
fold_stmt_inplace (gimple stmt)
{
- tree res;
- struct fold_stmt_r_data fold_stmt_r_data;
- struct walk_stmt_info wi;
- gimple_stmt_iterator si;
-
- bool changed = false;
- bool inside_addr_expr = false;
-
- fold_stmt_r_data.stmt = stmt;
- fold_stmt_r_data.changed_p = &changed;
- fold_stmt_r_data.inside_addr_expr_p = &inside_addr_expr;
-
- memset (&wi, 0, sizeof (wi));
- wi.info = &fold_stmt_r_data;
-
- /* Fold the individual operands.
- For example, fold instances of *&VAR into VAR, etc.
-
- It appears that, at one time, maybe_fold_stmt_indirect
- would cause the walk to return non-null in order to
- signal that the entire statement should be replaced with
- a call to _builtin_trap. This functionality is currently
- disabled, as noted in a FIXME, and cannot be supported here. */
- res = walk_gimple_op (stmt, fold_stmt_r, &wi);
- gcc_assert (!res);
-
- /* Fold the main computation performed by the statement. */
- switch (gimple_code (stmt))
- {
- case GIMPLE_ASSIGN:
- {
- unsigned old_num_ops;
- tree new_rhs;
- old_num_ops = gimple_num_ops (stmt);
- si = gsi_for_stmt (stmt);
- new_rhs = fold_gimple_assign (&si);
- if (new_rhs != NULL_TREE
- && get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops)
- {
- gimple_assign_set_rhs_from_tree (&si, new_rhs);
- changed = true;
- }
- gcc_assert (gsi_stmt (si) == stmt);
- break;
- }
- case GIMPLE_COND:
- changed |= fold_gimple_cond (stmt);
- break;
-
- default:
- break;
- }
-
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ bool changed = fold_stmt_1 (&gsi, true);
+ gcc_assert (gsi_stmt (gsi) == stmt);
return changed;
}
return NULL_TREE;
stack_save_gsi = gsi_for_stmt (stack_save);
- push_stmt_changes (gsi_stmt_ptr (&stack_save_gsi));
rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0);
if (!update_call_from_tree (&stack_save_gsi, rhs))
- {
- discard_stmt_changes (gsi_stmt_ptr (&stack_save_gsi));
- return NULL_TREE;
- }
- pop_stmt_changes (gsi_stmt_ptr (&stack_save_gsi));
+ return NULL_TREE;
/* No effect, so the statement will be deleted. */
return integer_zero_node;
}
if (lhs == NULL_TREE)
- new_stmt = gimple_build_nop ();
+ {
+ new_stmt = gimple_build_nop ();
+ unlink_stmt_vdef (stmt);
+ release_defs (stmt);
+ }
else
{
new_stmt = gimple_build_assign (lhs, tmp);
- copy_virtual_operands (new_stmt, stmt);
+ gimple_set_vuse (new_stmt, gimple_vuse (stmt));
+ gimple_set_vdef (new_stmt, gimple_vdef (stmt));
move_ssa_defining_stmt_for_defs (new_stmt, stmt);
}
}
old_stmt = stmt;
- push_stmt_changes (gsi_stmt_ptr (&i));
-
if (!update_call_from_tree (&i, result))
- {
- gimplify_and_update_call_from_tree (&i, result);
- todoflags |= TODO_rebuild_alias;
- }
+ {
+ gimplify_and_update_call_from_tree (&i, result);
+ todoflags |= TODO_update_address_taken;
+ }
stmt = gsi_stmt (i);
- pop_stmt_changes (gsi_stmt_ptr (&i));
+ update_stmt (stmt);
if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt)
&& gimple_purge_dead_eh_edges (bb))
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
- 0, /* tv_id */
+ TV_NONE, /* tv_id */
PROP_cfg | PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
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