/* Conditional constant propagation pass for the GNU compiler.
- Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
- Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+ 2010 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>
This file is part of GCC.
-
+
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.
-
+
GCC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
-
+
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
mark the outgoing edges as executable or not executable
depending on the predicate's value. This is then used when
visiting PHI nodes to know when a PHI argument can be ignored.
-
+
2- In ccp_visit_phi_node, if all the PHI arguments evaluate to the
same constant C, then the LHS of the PHI is set to C. This
#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 *);
+static bool ccp_fold_stmt (gimple_stmt_iterator *);
+
/* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */
static void
}
-
-/* If SYM is a constant variable with known value, return the value.
- NULL_TREE is returned otherwise. */
-
-tree
-get_symbol_constant_value (tree sym)
-{
- if (TREE_STATIC (sym)
- && TREE_READONLY (sym)
- && !MTAG_P (sym))
- {
- tree val = DECL_INITIAL (sym);
- if (val)
- {
- STRIP_USELESS_TYPE_CONVERSION (val);
- if (is_gimple_min_invariant (val))
- 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
- && 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 NULL_TREE;
-}
-
/* Compute a default value for variable VAR and store it in the
CONST_VAL array. The following rules are used to get default
values:
{
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 (has_constant_operand)
+ all_undefined_operands = false;
+
/* 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
for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
{
gimple stmt = gsi_stmt (i);
- bool is_varying = surely_varying_stmt_p (stmt);
+ bool is_varying;
+
+ /* If the statement is a control insn, then we do not
+ want to avoid simulating the statement once. Failure
+ to do so means that those edges will never get added. */
+ if (stmt_ends_bb_p (stmt))
+ is_varying = false;
+ else
+ is_varying = surely_varying_stmt_p (stmt);
if (is_varying)
{
/* 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.
+ free allocated storage.
Return TRUE when something was optimized. */
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, ccp_fold_stmt);
free (const_val);
const_val = NULL;
return SSA_PROP_NOT_INTERESTING;
}
-
/* CCP specific front-end to the non-destructive constant folding
routines.
static tree
ccp_fold (gimple stmt)
{
+ location_t loc = gimple_location (stmt);
switch (gimple_code (stmt))
{
case GIMPLE_ASSIGN:
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_loc (EXPR_LOCATION (rhs),
+ 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)
return get_symbol_constant_value (rhs);
return rhs;
}
-
+
case GIMPLE_UNARY_RHS:
{
/* Handle unary operators that can appear in GIMPLE form.
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)
if (!useless_type_conversion_p (TREE_TYPE (lhs),
TREE_TYPE (op0))
&& ((tem = maybe_fold_offset_to_address
- (op0, integer_zero_node, TREE_TYPE (lhs)))
+ (loc,
+ op0, integer_zero_node, TREE_TYPE (lhs)))
!= NULL_TREE))
return tem;
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_loc (loc, subcode,
+ gimple_expr_type (stmt), op0);
}
case GIMPLE_BINARY_RHS:
&& TREE_CODE (op0) == ADDR_EXPR
&& TREE_CODE (op1) == INTEGER_CST)
{
- tree lhs = gimple_assign_lhs (stmt);
- tree tem = maybe_fold_offset_to_address (op0, op1,
- TREE_TYPE (lhs));
+ tree tem = maybe_fold_offset_to_address
+ (loc, op0, op1, TREE_TYPE (op0));
if (tem != NULL_TREE)
return tem;
}
- return fold_binary (subcode, gimple_expr_type (stmt), op0, op1);
+ return fold_binary_loc (loc, subcode,
+ gimple_expr_type (stmt), op0, op1);
}
default:
args[i] = val->value;
}
}
- call = build_call_array (gimple_call_return_type (stmt),
- fn, gimple_call_num_args (stmt), args);
- retval = fold_call_expr (call, false);
+ call = build_call_array_loc (loc,
+ gimple_call_return_type (stmt),
+ fn, gimple_call_num_args (stmt), args);
+ retval = fold_call_expr (EXPR_LOCATION (call), call, false);
if (retval)
/* fold_call_expr wraps the result inside a NOP_EXPR. */
STRIP_NOPS (retval);
op1 = val->value;
}
- return fold_binary (code, boolean_type_node, op0, op1);
+ return fold_binary_loc (loc, code, boolean_type_node, op0, op1);
}
case GIMPLE_SWITCH:
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:
FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
if (tree_int_cst_equal (cfield, idx))
{
- STRIP_USELESS_TYPE_CONVERSION (cval);
+ STRIP_NOPS (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;
/* FIXME: Handle bit-fields. */
&& ! DECL_BIT_FIELD (cfield))
{
- STRIP_USELESS_TYPE_CONVERSION (cval);
+ STRIP_NOPS (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;
{
tree c = fold_const_aggregate_ref (TREE_OPERAND (t, 0));
if (c && TREE_CODE (c) == COMPLEX_CST)
- return fold_build1 (TREE_CODE (t), TREE_TYPE (t), c);
+ return fold_build1_loc (EXPR_LOCATION (t),
+ TREE_CODE (t), TREE_TYPE (t), c);
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;
}
if (code == GIMPLE_ASSIGN)
{
enum tree_code subcode = gimple_assign_rhs_code (stmt);
-
+
/* Other cases cannot satisfy is_gimple_min_invariant
without folding. */
if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS)
else if (code == GIMPLE_SWITCH)
simplified = gimple_switch_index (stmt);
else
- /* These cannot satisfy is_gimple_min_invariant without folding. */
- gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND);
+ /* These cannot satisfy is_gimple_min_invariant without folding. */
+ gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND);
}
is_constant = simplified && is_gimple_min_invariant (simplified);
return val;
}
+/* Fold the stmt at *GSI with CCP specific information that propagating
+ and regular folding does not catch. */
+
+static bool
+ccp_fold_stmt (gimple_stmt_iterator *gsi)
+{
+ gimple stmt = gsi_stmt (*gsi);
+
+ switch (gimple_code (stmt))
+ {
+ case GIMPLE_COND:
+ {
+ prop_value_t val;
+ /* Statement evaluation will handle type mismatches in constants
+ more gracefully than the final propagation. This allows us to
+ fold more conditionals here. */
+ val = evaluate_stmt (stmt);
+ if (val.lattice_val != CONSTANT
+ || TREE_CODE (val.value) != INTEGER_CST)
+ return false;
+
+ if (integer_zerop (val.value))
+ gimple_cond_make_false (stmt);
+ else
+ gimple_cond_make_true (stmt);
+
+ return true;
+ }
+
+ case GIMPLE_CALL:
+ {
+ tree lhs = gimple_call_lhs (stmt);
+ prop_value_t *val;
+ tree argt;
+ bool changed = false;
+ unsigned i;
+
+ /* If the call was folded into a constant make sure it goes
+ away even if we cannot propagate into all uses because of
+ type issues. */
+ if (lhs
+ && TREE_CODE (lhs) == SSA_NAME
+ && (val = get_value (lhs))
+ && val->lattice_val == CONSTANT)
+ {
+ tree new_rhs = unshare_expr (val->value);
+ bool res;
+ if (!useless_type_conversion_p (TREE_TYPE (lhs),
+ TREE_TYPE (new_rhs)))
+ new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs);
+ res = update_call_from_tree (gsi, new_rhs);
+ gcc_assert (res);
+ return true;
+ }
+
+ /* Propagate into the call arguments. Compared to replace_uses_in
+ this can use the argument slot types for type verification
+ instead of the current argument type. We also can safely
+ drop qualifiers here as we are dealing with constants anyway. */
+ argt = TYPE_ARG_TYPES (TREE_TYPE (TREE_TYPE (gimple_call_fn (stmt))));
+ for (i = 0; i < gimple_call_num_args (stmt) && argt;
+ ++i, argt = TREE_CHAIN (argt))
+ {
+ tree arg = gimple_call_arg (stmt, i);
+ if (TREE_CODE (arg) == SSA_NAME
+ && (val = get_value (arg))
+ && val->lattice_val == CONSTANT
+ && useless_type_conversion_p
+ (TYPE_MAIN_VARIANT (TREE_VALUE (argt)),
+ TYPE_MAIN_VARIANT (TREE_TYPE (val->value))))
+ {
+ gimple_call_set_arg (stmt, i, unshare_expr (val->value));
+ changed = true;
+ }
+ }
+
+ return changed;
+ }
+
+ case GIMPLE_ASSIGN:
+ {
+ tree lhs = gimple_assign_lhs (stmt);
+ prop_value_t *val;
+
+ /* If we have a load that turned out to be constant replace it
+ as we cannot propagate into all uses in all cases. */
+ if (gimple_assign_single_p (stmt)
+ && TREE_CODE (lhs) == SSA_NAME
+ && (val = get_value (lhs))
+ && val->lattice_val == CONSTANT)
+ {
+ tree rhs = unshare_expr (val->value);
+ if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
+ rhs = fold_convert (TREE_TYPE (lhs), rhs);
+ gimple_assign_set_rhs_from_tree (gsi, rhs);
+ return true;
+ }
+
+ return false;
+ }
+
+ default:
+ return false;
+ }
+}
+
/* Visit the assignment statement STMT. Set the value of its LHS to the
value computed by the RHS and store LHS in *OUTPUT_P. If STMT
creates virtual definitions, set the value of each new name to that
its evaluation changes the lattice value of its output, return
SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the
output value.
-
+
If STMT is a conditional branch and we can determine its truth
value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying
value, return SSA_PROP_VARYING. */
}
-struct gimple_opt_pass pass_ccp =
+struct gimple_opt_pass pass_ccp =
{
{
GIMPLE_PASS,
};
-/* A subroutine of fold_stmt_r. 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. */
+
+/* Try to optimize out __builtin_stack_restore. Optimize it out
+ if there is another __builtin_stack_restore in the same basic
+ block and no calls or ASM_EXPRs are in between, or if this block's
+ only outgoing edge is to EXIT_BLOCK and there are no calls or
+ ASM_EXPRs after this __builtin_stack_restore. */
static tree
-maybe_fold_offset_to_array_ref (tree base, tree offset, tree orig_type,
- bool allow_negative_idx)
+optimize_stack_restore (gimple_stmt_iterator i)
{
- tree min_idx, idx, idx_type, elt_offset = integer_zero_node;
- tree array_type, elt_type, elt_size;
- tree domain_type;
-
- /* If BASE is an ARRAY_REF, we can pick up another offset (this time
- measured in units of the size of elements type) from that ARRAY_REF).
- We can't do anything if either is variable.
-
- The case we handle here is *(&A[N]+O). */
- if (TREE_CODE (base) == ARRAY_REF)
- {
- tree low_bound = array_ref_low_bound (base);
-
- elt_offset = TREE_OPERAND (base, 1);
- if (TREE_CODE (low_bound) != INTEGER_CST
- || TREE_CODE (elt_offset) != INTEGER_CST)
- return NULL_TREE;
+ tree callee;
+ gimple stmt;
- elt_offset = int_const_binop (MINUS_EXPR, elt_offset, low_bound, 0);
- base = TREE_OPERAND (base, 0);
- }
+ basic_block bb = gsi_bb (i);
+ gimple call = gsi_stmt (i);
- /* Ignore stupid user tricks of indexing non-array variables. */
- array_type = TREE_TYPE (base);
- if (TREE_CODE (array_type) != ARRAY_TYPE)
- return NULL_TREE;
- elt_type = TREE_TYPE (array_type);
- if (!useless_type_conversion_p (orig_type, elt_type))
+ if (gimple_code (call) != GIMPLE_CALL
+ || gimple_call_num_args (call) != 1
+ || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME
+ || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0))))
return NULL_TREE;
- /* Use signed size type for intermediate computation on the index. */
- idx_type = signed_type_for (size_type_node);
-
- /* If OFFSET and ELT_OFFSET are zero, we don't care about the size of the
- element type (so we can use the alignment if it's not constant).
- Otherwise, compute the offset as an index by using a division. If the
- division isn't exact, then don't do anything. */
- elt_size = TYPE_SIZE_UNIT (elt_type);
- if (!elt_size)
- return NULL;
- if (integer_zerop (offset))
+ for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i))
{
- if (TREE_CODE (elt_size) != INTEGER_CST)
- elt_size = size_int (TYPE_ALIGN (elt_type));
+ stmt = gsi_stmt (i);
+ if (gimple_code (stmt) == GIMPLE_ASM)
+ return NULL_TREE;
+ if (gimple_code (stmt) != GIMPLE_CALL)
+ continue;
- idx = build_int_cst (idx_type, 0);
- }
- else
- {
- unsigned HOST_WIDE_INT lquo, lrem;
- HOST_WIDE_INT hquo, hrem;
- double_int soffset;
-
- /* The final array offset should be signed, so we need
- to sign-extend the (possibly pointer) offset here
- and use signed division. */
- soffset = double_int_sext (tree_to_double_int (offset),
- TYPE_PRECISION (TREE_TYPE (offset)));
- if (TREE_CODE (elt_size) != INTEGER_CST
- || div_and_round_double (TRUNC_DIV_EXPR, 0,
- soffset.low, soffset.high,
- TREE_INT_CST_LOW (elt_size),
- TREE_INT_CST_HIGH (elt_size),
- &lquo, &hquo, &lrem, &hrem)
- || lrem || hrem)
+ callee = gimple_call_fndecl (stmt);
+ if (!callee
+ || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL
+ /* All regular builtins are ok, just obviously not alloca. */
+ || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA)
return NULL_TREE;
- idx = build_int_cst_wide (idx_type, lquo, hquo);
+ if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE)
+ goto second_stack_restore;
}
- /* Assume the low bound is zero. If there is a domain type, get the
- low bound, if any, convert the index into that type, and add the
- low bound. */
- min_idx = build_int_cst (idx_type, 0);
- domain_type = TYPE_DOMAIN (array_type);
- if (domain_type)
- {
- idx_type = domain_type;
- if (TYPE_MIN_VALUE (idx_type))
- min_idx = TYPE_MIN_VALUE (idx_type);
- else
- min_idx = fold_convert (idx_type, min_idx);
+ if (!gsi_end_p (i))
+ return NULL_TREE;
- if (TREE_CODE (min_idx) != INTEGER_CST)
+ /* Allow one successor of the exit block, or zero successors. */
+ switch (EDGE_COUNT (bb->succs))
+ {
+ case 0:
+ break;
+ case 1:
+ if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR)
return NULL_TREE;
-
- elt_offset = fold_convert (idx_type, elt_offset);
+ break;
+ default:
+ return NULL_TREE;
}
+ second_stack_restore:
- if (!integer_zerop (min_idx))
- idx = int_const_binop (PLUS_EXPR, idx, min_idx, 0);
- if (!integer_zerop (elt_offset))
- idx = int_const_binop (PLUS_EXPR, idx, elt_offset, 0);
-
- /* Make sure to possibly truncate late after offsetting. */
- idx = fold_convert (idx_type, idx);
-
- /* We don't want to construct access past array bounds. For example
- char *(c[4]);
- c[3][2];
- should not be simplified into (*c)[14] or tree-vrp will
- give false warnings. The same is true for
- struct A { long x; char d[0]; } *a;
- (char *)a - 4;
- which should be not folded to &a->d[-8]. */
- if (domain_type
- && TYPE_MAX_VALUE (domain_type)
- && TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST)
+ /* If there's exactly one use, then zap the call to __builtin_stack_save.
+ If there are multiple uses, then the last one should remove the call.
+ In any case, whether the call to __builtin_stack_save can be removed
+ or not is irrelevant to removing the call to __builtin_stack_restore. */
+ if (has_single_use (gimple_call_arg (call, 0)))
{
- tree up_bound = TYPE_MAX_VALUE (domain_type);
+ gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0));
+ if (is_gimple_call (stack_save))
+ {
+ callee = gimple_call_fndecl (stack_save);
+ if (callee
+ && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL
+ && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE)
+ {
+ gimple_stmt_iterator stack_save_gsi;
+ tree rhs;
- if (tree_int_cst_lt (up_bound, idx)
- /* Accesses after the end of arrays of size 0 (gcc
- extension) and 1 are likely intentional ("struct
- hack"). */
- && compare_tree_int (up_bound, 1) > 0)
- return NULL_TREE;
- }
- if (domain_type
- && TYPE_MIN_VALUE (domain_type))
- {
- if (!allow_negative_idx
- && TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST
- && tree_int_cst_lt (idx, TYPE_MIN_VALUE (domain_type)))
- return NULL_TREE;
+ stack_save_gsi = gsi_for_stmt (stack_save);
+ rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0);
+ update_call_from_tree (&stack_save_gsi, rhs);
+ }
+ }
}
- else if (!allow_negative_idx
- && compare_tree_int (idx, 0) < 0)
- return NULL_TREE;
- return build4 (ARRAY_REF, elt_type, base, idx, NULL_TREE, NULL_TREE);
+ /* No effect, so the statement will be deleted. */
+ return integer_zero_node;
}
-
-/* Attempt to fold *(S+O) to S.X.
- BASE is a record type. OFFSET is a byte displacement. ORIG_TYPE
- is the desired result type. */
+/* If va_list type is a simple pointer and nothing special is needed,
+ optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0),
+ __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple
+ pointer assignment. */
static tree
-maybe_fold_offset_to_component_ref (tree record_type, tree base, tree offset,
- tree orig_type, bool base_is_ptr)
+optimize_stdarg_builtin (gimple call)
{
- tree f, t, field_type, tail_array_field, field_offset;
- tree ret;
- tree new_base;
+ tree callee, lhs, rhs, cfun_va_list;
+ bool va_list_simple_ptr;
+ location_t loc = gimple_location (call);
- if (TREE_CODE (record_type) != RECORD_TYPE
- && TREE_CODE (record_type) != UNION_TYPE
- && TREE_CODE (record_type) != QUAL_UNION_TYPE)
+ if (gimple_code (call) != GIMPLE_CALL)
return NULL_TREE;
- /* Short-circuit silly cases. */
- if (useless_type_conversion_p (record_type, orig_type))
- return NULL_TREE;
+ callee = gimple_call_fndecl (call);
+
+ cfun_va_list = targetm.fn_abi_va_list (callee);
+ va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list)
+ && (TREE_TYPE (cfun_va_list) == void_type_node
+ || TREE_TYPE (cfun_va_list) == char_type_node);
- tail_array_field = NULL_TREE;
- for (f = TYPE_FIELDS (record_type); f ; f = TREE_CHAIN (f))
+ switch (DECL_FUNCTION_CODE (callee))
{
- int cmp;
+ case BUILT_IN_VA_START:
+ if (!va_list_simple_ptr
+ || targetm.expand_builtin_va_start != NULL
+ || built_in_decls[BUILT_IN_NEXT_ARG] == NULL)
+ return NULL_TREE;
- if (TREE_CODE (f) != FIELD_DECL)
- continue;
- if (DECL_BIT_FIELD (f))
- continue;
+ if (gimple_call_num_args (call) != 2)
+ return NULL_TREE;
- if (!DECL_FIELD_OFFSET (f))
- continue;
- field_offset = byte_position (f);
- if (TREE_CODE (field_offset) != INTEGER_CST)
- continue;
+ lhs = gimple_call_arg (call, 0);
+ if (!POINTER_TYPE_P (TREE_TYPE (lhs))
+ || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
+ != TYPE_MAIN_VARIANT (cfun_va_list))
+ return NULL_TREE;
- /* ??? Java creates "interesting" fields for representing base classes.
- They have no name, and have no context. With no context, we get into
- trouble with nonoverlapping_component_refs_p. Skip them. */
- if (!DECL_FIELD_CONTEXT (f))
- continue;
+ lhs = build_fold_indirect_ref_loc (loc, lhs);
+ rhs = build_call_expr_loc (loc, built_in_decls[BUILT_IN_NEXT_ARG],
+ 1, integer_zero_node);
+ rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs);
+ return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
- /* The previous array field isn't at the end. */
- tail_array_field = NULL_TREE;
+ case BUILT_IN_VA_COPY:
+ if (!va_list_simple_ptr)
+ return NULL_TREE;
- /* Check to see if this offset overlaps with the field. */
- cmp = tree_int_cst_compare (field_offset, offset);
- if (cmp > 0)
- continue;
+ if (gimple_call_num_args (call) != 2)
+ return NULL_TREE;
- field_type = TREE_TYPE (f);
+ lhs = gimple_call_arg (call, 0);
+ if (!POINTER_TYPE_P (TREE_TYPE (lhs))
+ || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
+ != TYPE_MAIN_VARIANT (cfun_va_list))
+ return NULL_TREE;
- /* Here we exactly match the offset being checked. If the types match,
- then we can return that field. */
- if (cmp == 0
- && useless_type_conversion_p (orig_type, field_type))
- {
- if (base_is_ptr)
- base = build1 (INDIRECT_REF, record_type, base);
- t = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE);
- return t;
- }
-
- /* Don't care about offsets into the middle of scalars. */
- if (!AGGREGATE_TYPE_P (field_type))
- continue;
+ lhs = build_fold_indirect_ref_loc (loc, lhs);
+ rhs = gimple_call_arg (call, 1);
+ if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs))
+ != TYPE_MAIN_VARIANT (cfun_va_list))
+ return NULL_TREE;
- /* Check for array at the end of the struct. This is often
- used as for flexible array members. We should be able to
- turn this into an array access anyway. */
- if (TREE_CODE (field_type) == ARRAY_TYPE)
- tail_array_field = f;
+ rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs);
+ return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
- /* Check the end of the field against the offset. */
- if (!DECL_SIZE_UNIT (f)
- || TREE_CODE (DECL_SIZE_UNIT (f)) != INTEGER_CST)
- continue;
- t = int_const_binop (MINUS_EXPR, offset, field_offset, 1);
- if (!tree_int_cst_lt (t, DECL_SIZE_UNIT (f)))
- continue;
+ case BUILT_IN_VA_END:
+ /* No effect, so the statement will be deleted. */
+ return integer_zero_node;
- /* If we matched, then set offset to the displacement into
- this field. */
- if (base_is_ptr)
- new_base = build1 (INDIRECT_REF, record_type, base);
- else
- new_base = base;
- new_base = build3 (COMPONENT_REF, field_type, new_base, f, NULL_TREE);
-
- /* Recurse to possibly find the match. */
- ret = maybe_fold_offset_to_array_ref (new_base, t, orig_type,
- f == TYPE_FIELDS (record_type));
- if (ret)
- return ret;
- ret = maybe_fold_offset_to_component_ref (field_type, new_base, t,
- orig_type, false);
- if (ret)
- return ret;
+ default:
+ gcc_unreachable ();
}
-
- if (!tail_array_field)
- return NULL_TREE;
-
- f = tail_array_field;
- field_type = TREE_TYPE (f);
- offset = int_const_binop (MINUS_EXPR, offset, byte_position (f), 1);
-
- /* If we get here, we've got an aggregate field, and a possibly
- nonzero offset into them. Recurse and hope for a valid match. */
- if (base_is_ptr)
- base = build1 (INDIRECT_REF, record_type, base);
- base = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE);
-
- t = maybe_fold_offset_to_array_ref (base, offset, orig_type,
- f == TYPE_FIELDS (record_type));
- if (t)
- return t;
- return maybe_fold_offset_to_component_ref (field_type, base, offset,
- orig_type, false);
-}
-
-/* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE->field_of_orig_type
- or BASE[index] or by combination of those.
-
- Before attempting the conversion strip off existing ADDR_EXPRs and
- handled component refs. */
-
-tree
-maybe_fold_offset_to_reference (tree base, tree offset, tree orig_type)
-{
- tree ret;
- tree type;
- bool base_is_ptr = true;
-
- STRIP_NOPS (base);
- if (TREE_CODE (base) == ADDR_EXPR)
- {
- base_is_ptr = false;
-
- base = TREE_OPERAND (base, 0);
-
- /* Handle case where existing COMPONENT_REF pick e.g. wrong field of union,
- so it needs to be removed and new COMPONENT_REF constructed.
- The wrong COMPONENT_REF are often constructed by folding the
- (type *)&object within the expression (type *)&object+offset */
- if (handled_component_p (base))
- {
- HOST_WIDE_INT sub_offset, size, maxsize;
- tree newbase;
- newbase = get_ref_base_and_extent (base, &sub_offset,
- &size, &maxsize);
- gcc_assert (newbase);
- if (size == maxsize
- && size != -1
- && !(sub_offset & (BITS_PER_UNIT - 1)))
- {
- base = newbase;
- if (sub_offset)
- offset = int_const_binop (PLUS_EXPR, offset,
- build_int_cst (TREE_TYPE (offset),
- sub_offset / BITS_PER_UNIT), 1);
- }
- }
- if (useless_type_conversion_p (orig_type, TREE_TYPE (base))
- && integer_zerop (offset))
- return base;
- type = TREE_TYPE (base);
- }
- else
- {
- base_is_ptr = true;
- if (!POINTER_TYPE_P (TREE_TYPE (base)))
- return NULL_TREE;
- type = TREE_TYPE (TREE_TYPE (base));
- }
- ret = maybe_fold_offset_to_component_ref (type, base, offset,
- orig_type, base_is_ptr);
- if (!ret)
- {
- if (base_is_ptr)
- base = build1 (INDIRECT_REF, type, base);
- ret = maybe_fold_offset_to_array_ref (base, offset, orig_type, true);
- }
- return ret;
-}
-
-/* Attempt to express (ORIG_TYPE)&BASE+OFFSET as &BASE->field_of_orig_type
- or &BASE[index] or by combination of those.
-
- Before attempting the conversion strip off existing component refs. */
-
-tree
-maybe_fold_offset_to_address (tree addr, tree offset, tree orig_type)
-{
- tree t;
-
- gcc_assert (POINTER_TYPE_P (TREE_TYPE (addr))
- && POINTER_TYPE_P (orig_type));
-
- t = maybe_fold_offset_to_reference (addr, offset, TREE_TYPE (orig_type));
- if (t != NULL_TREE)
- {
- tree orig = addr;
- tree ptr_type;
-
- /* For __builtin_object_size to function correctly we need to
- make sure not to fold address arithmetic so that we change
- reference from one array to another. This would happen for
- example for
-
- struct X { char s1[10]; char s2[10] } s;
- char *foo (void) { return &s.s2[-4]; }
-
- where we need to avoid generating &s.s1[6]. As the C and
- C++ frontends create different initial trees
- (char *) &s.s1 + -4 vs. &s.s1[-4] we have to do some
- sophisticated comparisons here. Note that checking for the
- condition after the fact is easier than trying to avoid doing
- the folding. */
- STRIP_NOPS (orig);
- if (TREE_CODE (orig) == ADDR_EXPR)
- orig = TREE_OPERAND (orig, 0);
- if ((TREE_CODE (orig) == ARRAY_REF
- || (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))
- && !operand_equal_p (TREE_CODE (orig) == ARRAY_REF
- ? TREE_OPERAND (orig, 0) : orig,
- TREE_CODE (t) == ARRAY_REF
- ? TREE_OPERAND (t, 0) : t, 0))
- return NULL_TREE;
-
- ptr_type = build_pointer_type (TREE_TYPE (t));
- if (!useless_type_conversion_p (orig_type, ptr_type))
- return NULL_TREE;
- return build_fold_addr_expr_with_type (t, ptr_type);
- }
-
- return NULL_TREE;
-}
-
-/* A subroutine of fold_stmt_r. Attempt to simplify *(BASE+OFFSET).
- Return the simplified expression, or NULL if nothing could be done. */
-
-static tree
-maybe_fold_stmt_indirect (tree expr, tree base, tree offset)
-{
- tree t;
- bool volatile_p = TREE_THIS_VOLATILE (expr);
-
- /* We may well have constructed a double-nested PLUS_EXPR via multiple
- substitutions. Fold that down to one. Remove NON_LVALUE_EXPRs that
- are sometimes added. */
- base = fold (base);
- STRIP_TYPE_NOPS (base);
- TREE_OPERAND (expr, 0) = base;
-
- /* One possibility is that the address reduces to a string constant. */
- t = fold_read_from_constant_string (expr);
- if (t)
- return t;
-
- /* Add in any offset from a POINTER_PLUS_EXPR. */
- if (TREE_CODE (base) == POINTER_PLUS_EXPR)
- {
- tree offset2;
-
- offset2 = TREE_OPERAND (base, 1);
- if (TREE_CODE (offset2) != INTEGER_CST)
- return NULL_TREE;
- base = TREE_OPERAND (base, 0);
-
- offset = fold_convert (sizetype,
- int_const_binop (PLUS_EXPR, offset, offset2, 1));
- }
-
- if (TREE_CODE (base) == ADDR_EXPR)
- {
- tree base_addr = base;
-
- /* Strip the ADDR_EXPR. */
- base = TREE_OPERAND (base, 0);
-
- /* Fold away CONST_DECL to its value, if the type is scalar. */
- if (TREE_CODE (base) == CONST_DECL
- && is_gimple_min_invariant (DECL_INITIAL (base)))
- return DECL_INITIAL (base);
-
- /* Try folding *(&B+O) to B.X. */
- t = maybe_fold_offset_to_reference (base_addr, offset,
- TREE_TYPE (expr));
- 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;
- return t;
- }
- }
- else
- {
- /* We can get here for out-of-range string constant accesses,
- such as "_"[3]. Bail out of the entire substitution search
- and arrange for the entire statement to be replaced by a
- call to __builtin_trap. In all likelihood this will all be
- constant-folded away, but in the meantime we can't leave with
- something that get_expr_operands can't understand. */
-
- t = base;
- STRIP_NOPS (t);
- if (TREE_CODE (t) == ADDR_EXPR
- && TREE_CODE (TREE_OPERAND (t, 0)) == STRING_CST)
- {
- /* FIXME: Except that this causes problems elsewhere with dead
- code not being deleted, and we die in the rtl expanders
- because we failed to remove some ssa_name. In the meantime,
- just return zero. */
- /* FIXME2: This condition should be signaled by
- fold_read_from_constant_string directly, rather than
- re-checking for it here. */
- return integer_zero_node;
- }
-
- /* Try folding *(B+O) to B->X. Still an improvement. */
- if (POINTER_TYPE_P (TREE_TYPE (base)))
- {
- t = maybe_fold_offset_to_reference (base, offset,
- TREE_TYPE (expr));
- if (t)
- return t;
- }
- }
-
- /* Otherwise we had an offset that we could not simplify. */
- return NULL_TREE;
-}
-
-
-/* A quaint feature extant in our address arithmetic is that there
- can be hidden type changes here. The type of the result need
- not be the same as the type of the input pointer.
-
- What we're after here is an expression of the form
- (T *)(&array + const)
- where array is OP0, const is OP1, RES_TYPE is T and
- the cast doesn't actually exist, but is implicit in the
- type of the POINTER_PLUS_EXPR. We'd like to turn this into
- &array[x]
- which may be able to propagate further. */
-
-tree
-maybe_fold_stmt_addition (tree res_type, tree op0, tree op1)
-{
- 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);
-
- /* 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)
- {
- tree array_obj = TREE_OPERAND (op0, 0);
- tree array_idx = TREE_OPERAND (op0, 1);
- tree elt_type = TREE_TYPE (op0);
- tree elt_size = TYPE_SIZE_UNIT (elt_type);
- tree min_idx;
-
- if (TREE_CODE (array_idx) != INTEGER_CST)
- break;
- if (TREE_CODE (elt_size) != INTEGER_CST)
- break;
-
- /* Un-bias the index by the min index of the array type. */
- min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj));
- if (min_idx)
- {
- min_idx = TYPE_MIN_VALUE (min_idx);
- if (min_idx)
- {
- if (TREE_CODE (min_idx) != INTEGER_CST)
- break;
-
- array_idx = fold_convert (TREE_TYPE (min_idx), array_idx);
- if (!integer_zerop (min_idx))
- array_idx = int_const_binop (MINUS_EXPR, array_idx,
- min_idx, 0);
- }
- }
-
- /* Convert the index to a byte offset. */
- array_idx = fold_convert (sizetype, array_idx);
- array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0);
-
- /* Update the operands for the next round, or for folding. */
- op1 = int_const_binop (PLUS_EXPR,
- array_idx, op1, 0);
- op0 = array_obj;
- }
-
- ptd_type = TREE_TYPE (res_type);
- /* If we want a pointer to void, reconstruct the reference from the
- array element type. A pointer to that can be trivially converted
- to void *. This happens as we fold (void *)(ptr p+ off). */
- if (VOID_TYPE_P (ptd_type)
- && TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
- ptd_type = TREE_TYPE (TREE_TYPE (op0));
-
- /* At which point we can try some of the same things as for indirects. */
- t = maybe_fold_offset_to_array_ref (op0, op1, ptd_type, true);
- if (!t)
- t = maybe_fold_offset_to_component_ref (TREE_TYPE (op0), op0, op1,
- ptd_type, false);
- if (t)
- t = build1 (ADDR_EXPR, res_type, t);
-
- 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. */
-
-static tree
-fold_stmt_r (tree *expr_p, int *walk_subtrees, void *data)
-{
- 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);
-
- 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;
-
- /* ??? It'd be nice if walk_tree had a pre-order option. */
- switch (TREE_CODE (expr))
- {
- case INDIRECT_REF:
- t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL);
- if (t)
- return t;
- *walk_subtrees = 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 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;
-
- /* ??? 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;
- }
-
- 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
- is not NULL and, for TYPE == 0, its value is not equal to the length
- we determine or if we are unable to determine the length or value,
- return false. VISITED is a bitmap of visited variables.
- TYPE is 0 if string length should be returned, 1 for maximum string
- length and 2 for maximum value ARG can have. */
-
-static bool
-get_maxval_strlen (tree arg, tree *length, bitmap visited, int type)
-{
- tree var, val;
- gimple def_stmt;
-
- if (TREE_CODE (arg) != SSA_NAME)
- {
- if (TREE_CODE (arg) == COND_EXPR)
- return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type)
- && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type);
- /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */
- else if (TREE_CODE (arg) == ADDR_EXPR
- && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF
- && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1)))
- {
- tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0);
- if (TREE_CODE (aop0) == INDIRECT_REF
- && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME)
- return get_maxval_strlen (TREE_OPERAND (aop0, 0),
- length, visited, type);
- }
-
- if (type == 2)
- {
- val = arg;
- if (TREE_CODE (val) != INTEGER_CST
- || tree_int_cst_sgn (val) < 0)
- return false;
- }
- else
- val = c_strlen (arg, 1);
- if (!val)
- return false;
-
- if (*length)
- {
- if (type > 0)
- {
- if (TREE_CODE (*length) != INTEGER_CST
- || TREE_CODE (val) != INTEGER_CST)
- return false;
-
- if (tree_int_cst_lt (*length, val))
- *length = val;
- return true;
- }
- else if (simple_cst_equal (val, *length) != 1)
- return false;
- }
-
- *length = val;
- return true;
- }
-
- /* If we were already here, break the infinite cycle. */
- if (bitmap_bit_p (visited, SSA_NAME_VERSION (arg)))
- return true;
- bitmap_set_bit (visited, SSA_NAME_VERSION (arg));
-
- var = arg;
- def_stmt = SSA_NAME_DEF_STMT (var);
-
- switch (gimple_code (def_stmt))
- {
- case GIMPLE_ASSIGN:
- /* The RHS of the statement defining VAR must either have a
- constant length or come from another SSA_NAME with a constant
- length. */
- if (gimple_assign_single_p (def_stmt)
- || gimple_assign_unary_nop_p (def_stmt))
- {
- tree rhs = gimple_assign_rhs1 (def_stmt);
- return get_maxval_strlen (rhs, length, visited, type);
- }
- return false;
-
- case GIMPLE_PHI:
- {
- /* All the arguments of the PHI node must have the same constant
- length. */
- unsigned i;
-
- for (i = 0; i < gimple_phi_num_args (def_stmt); i++)
- {
- tree arg = gimple_phi_arg (def_stmt, i)->def;
-
- /* If this PHI has itself as an argument, we cannot
- determine the string length of this argument. However,
- if we can find a constant string length for the other
- PHI args then we can still be sure that this is a
- constant string length. So be optimistic and just
- continue with the next argument. */
- if (arg == gimple_phi_result (def_stmt))
- continue;
-
- if (!get_maxval_strlen (arg, length, visited, type))
- return false;
- }
- }
- return true;
-
- default:
- return false;
- }
-}
-
-
-/* Fold builtin call in statement STMT. Returns a simplified tree.
- We may return a non-constant expression, including another call
- to a different function and with different arguments, e.g.,
- substituting memcpy for strcpy when the string length is known.
- Note that some builtins expand into inline code that may not
- be valid in GIMPLE. Callers must take care. */
-
-static tree
-ccp_fold_builtin (gimple stmt)
-{
- tree result, val[3];
- tree callee, a;
- int arg_mask, i, type;
- bitmap visited;
- bool ignore;
- int nargs;
-
- gcc_assert (is_gimple_call (stmt));
-
- ignore = (gimple_call_lhs (stmt) == NULL);
-
- /* First try the generic builtin folder. If that succeeds, return the
- result directly. */
- result = fold_call_stmt (stmt, ignore);
- if (result)
- {
- if (ignore)
- STRIP_NOPS (result);
- return result;
- }
-
- /* Ignore MD builtins. */
- callee = gimple_call_fndecl (stmt);
- if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD)
- return NULL_TREE;
-
- /* If the builtin could not be folded, and it has no argument list,
- we're done. */
- nargs = gimple_call_num_args (stmt);
- if (nargs == 0)
- return NULL_TREE;
-
- /* Limit the work only for builtins we know how to simplify. */
- switch (DECL_FUNCTION_CODE (callee))
- {
- case BUILT_IN_STRLEN:
- case BUILT_IN_FPUTS:
- case BUILT_IN_FPUTS_UNLOCKED:
- arg_mask = 1;
- type = 0;
- break;
- case BUILT_IN_STRCPY:
- case BUILT_IN_STRNCPY:
- arg_mask = 2;
- type = 0;
- break;
- case BUILT_IN_MEMCPY_CHK:
- case BUILT_IN_MEMPCPY_CHK:
- case BUILT_IN_MEMMOVE_CHK:
- case BUILT_IN_MEMSET_CHK:
- case BUILT_IN_STRNCPY_CHK:
- arg_mask = 4;
- type = 2;
- break;
- case BUILT_IN_STRCPY_CHK:
- case BUILT_IN_STPCPY_CHK:
- arg_mask = 2;
- type = 1;
- break;
- case BUILT_IN_SNPRINTF_CHK:
- case BUILT_IN_VSNPRINTF_CHK:
- arg_mask = 2;
- type = 2;
- break;
- default:
- return NULL_TREE;
- }
-
- /* Try to use the dataflow information gathered by the CCP process. */
- visited = BITMAP_ALLOC (NULL);
-
- memset (val, 0, sizeof (val));
- for (i = 0; i < nargs; i++)
- {
- if ((arg_mask >> i) & 1)
- {
- a = gimple_call_arg (stmt, i);
- bitmap_clear (visited);
- if (!get_maxval_strlen (a, &val[i], visited, type))
- val[i] = NULL_TREE;
- }
- }
-
- BITMAP_FREE (visited);
-
- result = NULL_TREE;
- switch (DECL_FUNCTION_CODE (callee))
- {
- case BUILT_IN_STRLEN:
- if (val[0])
- {
- tree new_val =
- fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]);
-
- /* If the result is not a valid gimple value, or not a cast
- of a valid gimple value, then we can not use the result. */
- if (is_gimple_val (new_val)
- || (is_gimple_cast (new_val)
- && is_gimple_val (TREE_OPERAND (new_val, 0))))
- return new_val;
- }
- break;
-
- case BUILT_IN_STRCPY:
- if (val[1] && is_gimple_val (val[1]) && nargs == 2)
- result = fold_builtin_strcpy (callee,
- gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- val[1]);
- break;
-
- case BUILT_IN_STRNCPY:
- if (val[1] && is_gimple_val (val[1]) && nargs == 3)
- result = fold_builtin_strncpy (callee,
- gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 2),
- val[1]);
- break;
-
- case BUILT_IN_FPUTS:
- 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]);
- 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]))
- result = fold_builtin_memory_chk (callee,
- gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 2),
- gimple_call_arg (stmt, 3),
- val[2], ignore,
- DECL_FUNCTION_CODE (callee));
- break;
-
- case BUILT_IN_STRCPY_CHK:
- case BUILT_IN_STPCPY_CHK:
- if (val[1] && is_gimple_val (val[1]))
- result = fold_builtin_stxcpy_chk (callee,
- gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 2),
- val[1], ignore,
- DECL_FUNCTION_CODE (callee));
- break;
-
- case BUILT_IN_STRNCPY_CHK:
- if (val[2] && is_gimple_val (val[2]))
- result = fold_builtin_strncpy_chk (gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 2),
- gimple_call_arg (stmt, 3),
- val[2]);
- break;
-
- case BUILT_IN_SNPRINTF_CHK:
- case BUILT_IN_VSNPRINTF_CHK:
- if (val[1] && is_gimple_val (val[1]))
- result = gimple_fold_builtin_snprintf_chk (stmt, val[1],
- DECL_FUNCTION_CODE (callee));
- break;
-
- default:
- gcc_unreachable ();
- }
-
- if (result && ignore)
- result = fold_ignored_result (result);
- return result;
-}
-
-/* Attempt to fold an assignment statement pointed-to by SI. Returns a
- replacement rhs for the statement or NULL_TREE if no simplification
- could be made. It is assumed that the operands have been previously
- folded. */
-
-static tree
-fold_gimple_assign (gimple_stmt_iterator *si)
-{
- gimple stmt = gsi_stmt (*si);
- enum tree_code subcode = gimple_assign_rhs_code (stmt);
-
- tree result = NULL;
-
- 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));
- }
-
- /* If we couldn't fold the RHS, hand over to the generic
- fold routines. */
- if (result == NULL_TREE)
- result = fold (rhs);
-
- /* Strip away useless type conversions. Both the NON_LVALUE_EXPR
- that may have been added by fold, and "useless" type
- conversions that might now be apparent due to propagation. */
- STRIP_USELESS_TYPE_CONVERSION (result);
-
- 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;
- }
- break;
-
- case GIMPLE_UNARY_RHS:
- {
- tree rhs = gimple_assign_rhs1 (stmt);
-
- result = fold_unary (subcode, gimple_expr_type (stmt), rhs);
- if (result)
- {
- /* 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 (CONVERT_EXPR_CODE_P (subcode)
- && TREE_CODE (result) == INTEGER_CST
- && TREE_CODE (rhs) == INTEGER_CST)
- TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs);
-
- STRIP_USELESS_TYPE_CONVERSION (result);
- if (valid_gimple_rhs_p (result))
- return result;
- }
- else if (CONVERT_EXPR_CODE_P (subcode)
- && POINTER_TYPE_P (gimple_expr_type (stmt))
- && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))
- {
- tree type = gimple_expr_type (stmt);
- tree t = maybe_fold_offset_to_address (gimple_assign_rhs1 (stmt),
- integer_zero_node, type);
- if (t)
- return t;
- }
- }
- 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));
-
- if (!result)
- result = fold_binary (subcode,
- TREE_TYPE (gimple_assign_lhs (stmt)),
- gimple_assign_rhs1 (stmt),
- gimple_assign_rhs2 (stmt));
-
- if (result)
- {
- STRIP_USELESS_TYPE_CONVERSION (result);
- if (valid_gimple_rhs_p (result))
- return result;
- }
- break;
-
- case GIMPLE_INVALID_RHS:
- gcc_unreachable ();
- }
-
- return NULL_TREE;
-}
-
-/* Attempt to fold a conditional statement. Return true if any changes were
- made. We only attempt to fold the condition expression, and do not perform
- any transformation that would require alteration of the cfg. It is
- assumed that the operands have been previously folded. */
-
-static bool
-fold_gimple_cond (gimple stmt)
-{
- tree result = fold_binary (gimple_cond_code (stmt),
- boolean_type_node,
- gimple_cond_lhs (stmt),
- gimple_cond_rhs (stmt));
-
- if (result)
- {
- STRIP_USELESS_TYPE_CONVERSION (result);
- if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result))
- {
- gimple_cond_set_condition_from_tree (stmt, result);
- return true;
- }
- }
-
- return false;
-}
-
-
-/* Attempt to fold a call statement referenced by the statement iterator GSI.
- The statement may be replaced by another statement, e.g., if the call
- simplifies to a constant value. Return true if any changes were made.
- It is assumed that the operands have been previously folded. */
-
-static bool
-fold_gimple_call (gimple_stmt_iterator *gsi)
-{
- gimple stmt = gsi_stmt (*gsi);
-
- tree callee = gimple_call_fndecl (stmt);
-
- /* Check for builtins that CCP can handle using information not
- available in the generic fold routines. */
- if (callee && DECL_BUILT_IN (callee))
- {
- tree result = ccp_fold_builtin (stmt);
-
- if (result)
- return update_call_from_tree (gsi, result);
- }
- else
- {
- /* Check for resolvable OBJ_TYPE_REF. The only sorts we can resolve
- here are when we've propagated the address of a decl into the
- object slot. */
- /* ??? Should perhaps do this in fold proper. However, doing it
- there requires that we create a new CALL_EXPR, and that requires
- copying EH region info to the new node. Easier to just do it
- here where we can just smash the call operand. */
- /* ??? Is there a good reason not to do this in fold_stmt_inplace? */
- callee = gimple_call_fn (stmt);
- if (TREE_CODE (callee) == OBJ_TYPE_REF
- && lang_hooks.fold_obj_type_ref
- && TREE_CODE (OBJ_TYPE_REF_OBJECT (callee)) == ADDR_EXPR
- && DECL_P (TREE_OPERAND
- (OBJ_TYPE_REF_OBJECT (callee), 0)))
- {
- tree t;
-
- /* ??? Caution: Broken ADDR_EXPR semantics means that
- looking at the type of the operand of the addr_expr
- can yield an array type. See silly exception in
- check_pointer_types_r. */
- t = TREE_TYPE (TREE_TYPE (OBJ_TYPE_REF_OBJECT (callee)));
- t = lang_hooks.fold_obj_type_ref (callee, t);
- if (t)
- {
- gimple_call_set_fn (stmt, t);
- return true;
- }
- }
- }
-
- 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. */
-
-bool
-fold_stmt (gimple_stmt_iterator *gsi)
-{
- 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);
-
- /* Fold the main computation performed by the statement. */
- switch (gimple_code (stmt))
- {
- case GIMPLE_ASSIGN:
- {
- tree new_rhs = fold_gimple_assign (gsi);
- if (new_rhs != NULL_TREE)
- {
- 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:
- /* The entire statement may be replaced in this case. */
- changed |= fold_gimple_call (gsi);
- break;
-
- default:
- return changed;
- break;
- }
-
- return changed;
-}
-
-/* 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. */
-
-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;
- }
-
- return changed;
-}
-
-/* Try to optimize out __builtin_stack_restore. Optimize it out
- if there is another __builtin_stack_restore in the same basic
- block and no calls or ASM_EXPRs are in between, or if this block's
- only outgoing edge is to EXIT_BLOCK and there are no calls or
- ASM_EXPRs after this __builtin_stack_restore. */
-
-static tree
-optimize_stack_restore (gimple_stmt_iterator i)
-{
- tree callee, rhs;
- gimple stmt, stack_save;
- gimple_stmt_iterator stack_save_gsi;
-
- basic_block bb = gsi_bb (i);
- gimple call = gsi_stmt (i);
-
- if (gimple_code (call) != GIMPLE_CALL
- || gimple_call_num_args (call) != 1
- || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME
- || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0))))
- return NULL_TREE;
-
- for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i))
- {
- stmt = gsi_stmt (i);
- if (gimple_code (stmt) == GIMPLE_ASM)
- return NULL_TREE;
- if (gimple_code (stmt) != GIMPLE_CALL)
- continue;
-
- callee = gimple_call_fndecl (stmt);
- if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL)
- return NULL_TREE;
-
- if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE)
- break;
- }
-
- if (gsi_end_p (i)
- && (! single_succ_p (bb)
- || single_succ_edge (bb)->dest != EXIT_BLOCK_PTR))
- return NULL_TREE;
-
- stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0));
- if (gimple_code (stack_save) != GIMPLE_CALL
- || gimple_call_lhs (stack_save) != gimple_call_arg (call, 0)
- || stmt_could_throw_p (stack_save)
- || !has_single_use (gimple_call_arg (call, 0)))
- return NULL_TREE;
-
- callee = gimple_call_fndecl (stack_save);
- if (!callee
- || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL
- || DECL_FUNCTION_CODE (callee) != BUILT_IN_STACK_SAVE
- || gimple_call_num_args (stack_save) != 0)
- 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));
-
- /* No effect, so the statement will be deleted. */
- return integer_zero_node;
-}
-
-/* If va_list type is a simple pointer and nothing special is needed,
- optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0),
- __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple
- pointer assignment. */
-
-static tree
-optimize_stdarg_builtin (gimple call)
-{
- tree callee, lhs, rhs, cfun_va_list;
- bool va_list_simple_ptr;
-
- if (gimple_code (call) != GIMPLE_CALL)
- return NULL_TREE;
-
- callee = gimple_call_fndecl (call);
-
- cfun_va_list = targetm.fn_abi_va_list (callee);
- va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list)
- && (TREE_TYPE (cfun_va_list) == void_type_node
- || TREE_TYPE (cfun_va_list) == char_type_node);
-
- switch (DECL_FUNCTION_CODE (callee))
- {
- case BUILT_IN_VA_START:
- if (!va_list_simple_ptr
- || targetm.expand_builtin_va_start != NULL
- || built_in_decls[BUILT_IN_NEXT_ARG] == NULL)
- return NULL_TREE;
-
- if (gimple_call_num_args (call) != 2)
- return NULL_TREE;
-
- lhs = gimple_call_arg (call, 0);
- if (!POINTER_TYPE_P (TREE_TYPE (lhs))
- || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
- != TYPE_MAIN_VARIANT (cfun_va_list))
- return NULL_TREE;
-
- lhs = build_fold_indirect_ref (lhs);
- rhs = build_call_expr (built_in_decls[BUILT_IN_NEXT_ARG],
- 1, integer_zero_node);
- rhs = fold_convert (TREE_TYPE (lhs), rhs);
- return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
-
- case BUILT_IN_VA_COPY:
- if (!va_list_simple_ptr)
- return NULL_TREE;
-
- if (gimple_call_num_args (call) != 2)
- return NULL_TREE;
-
- lhs = gimple_call_arg (call, 0);
- if (!POINTER_TYPE_P (TREE_TYPE (lhs))
- || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
- != TYPE_MAIN_VARIANT (cfun_va_list))
- return NULL_TREE;
-
- lhs = build_fold_indirect_ref (lhs);
- rhs = gimple_call_arg (call, 1);
- if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs))
- != TYPE_MAIN_VARIANT (cfun_va_list))
- return NULL_TREE;
-
- rhs = fold_convert (TREE_TYPE (lhs), rhs);
- return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
-
- case BUILT_IN_VA_END:
- /* No effect, so the statement will be deleted. */
- return integer_zero_node;
-
- default:
- gcc_unreachable ();
- }
-}
-
-/* Convert EXPR into a GIMPLE value suitable for substitution on the
- RHS of an assignment. Insert the necessary statements before
- iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL
- is replaced. If the call is expected to produces a result, then it
- is replaced by an assignment of the new RHS to the result variable.
- If the result is to be ignored, then the call is replaced by a
- GIMPLE_NOP. */
-
-static void
-gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr)
-{
- tree lhs;
- tree tmp = NULL_TREE; /* Silence warning. */
- gimple stmt, new_stmt;
- gimple_stmt_iterator i;
- gimple_seq stmts = gimple_seq_alloc();
- struct gimplify_ctx gctx;
-
- stmt = gsi_stmt (*si_p);
-
- gcc_assert (is_gimple_call (stmt));
-
- lhs = gimple_call_lhs (stmt);
-
- push_gimplify_context (&gctx);
-
- if (lhs == NULL_TREE)
- gimplify_and_add (expr, &stmts);
- else
- tmp = get_initialized_tmp_var (expr, &stmts, NULL);
-
- pop_gimplify_context (NULL);
-
- if (gimple_has_location (stmt))
- annotate_all_with_location (stmts, gimple_location (stmt));
-
- /* The replacement can expose previously unreferenced variables. */
- for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i))
- {
- new_stmt = gsi_stmt (i);
- find_new_referenced_vars (new_stmt);
- gsi_insert_before (si_p, new_stmt, GSI_NEW_STMT);
- mark_symbols_for_renaming (new_stmt);
- gsi_next (si_p);
- }
-
- if (lhs == NULL_TREE)
- new_stmt = gimple_build_nop ();
- else
- {
- new_stmt = gimple_build_assign (lhs, tmp);
- copy_virtual_operands (new_stmt, stmt);
- move_ssa_defining_stmt_for_defs (new_stmt, stmt);
- }
-
- gimple_set_location (new_stmt, gimple_location (stmt));
- gsi_replace (si_p, new_stmt, false);
-}
+}
/* A simple pass that attempts to fold all builtin functions. This pass
is run after we've propagated as many constants as we can. */
bool cfg_changed = false;
basic_block bb;
unsigned int todoflags = 0;
-
+
FOR_EACH_BB (bb)
{
gimple_stmt_iterator i;
}
fcode = DECL_FUNCTION_CODE (callee);
- result = ccp_fold_builtin (stmt);
+ result = gimple_fold_builtin (stmt);
if (result)
gimple_remove_stmt_histograms (cfun, 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))
gsi_next (&i);
}
}
-
+
/* Delete unreachable blocks. */
if (cfg_changed)
todoflags |= TODO_cleanup_cfg;
-
+
return todoflags;
}
-struct gimple_opt_pass pass_fold_builtins =
+struct gimple_opt_pass pass_fold_builtins =
{
{
GIMPLE_PASS,
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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