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 2, or (at your option) any
+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
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/* Conditional constant propagation (CCP) is based on the SSA
propagation engine (tree-ssa-propagate.c). Constant assignments of
#include "tree-flow.h"
#include "tree-pass.h"
#include "tree-ssa-propagate.h"
+#include "value-prof.h"
#include "langhooks.h"
#include "target.h"
#include "toplev.h"
}
-/* The regular is_gimple_min_invariant does a shallow test of the object.
- It assumes that full gimplification has happened, or will happen on the
- object. For a value coming from DECL_INITIAL, this is not true, so we
- have to be more strict ourselves. */
-
-static bool
-ccp_decl_initial_min_invariant (tree t)
-{
- if (!is_gimple_min_invariant (t))
- return false;
- if (TREE_CODE (t) == ADDR_EXPR)
- {
- /* Inline and unroll is_gimple_addressable. */
- while (1)
- {
- t = TREE_OPERAND (t, 0);
- if (is_gimple_id (t))
- return true;
- if (!handled_component_p (t))
- return false;
- }
- }
- return true;
-}
-
/* If SYM is a constant variable with known value, return the value.
NULL_TREE is returned otherwise. */
-static tree
+tree
get_symbol_constant_value (tree sym)
{
if (TREE_STATIC (sym)
&& !MTAG_P (sym))
{
tree val = DECL_INITIAL (sym);
- if (val
- && ccp_decl_initial_min_invariant (val))
- return val;
+ 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 intializer 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;
static inline prop_value_t *
get_value (tree var)
{
- prop_value_t *val = &const_val[SSA_NAME_VERSION (var)];
+ prop_value_t *val;
+ if (const_val == NULL)
+ return NULL;
+
+ val = &const_val[SSA_NAME_VERSION (var)];
if (val->lattice_val == UNINITIALIZED)
*val = get_default_value (var);
If STMT has no operands, then return CONSTANT.
- Else if any operands of STMT are undefined, then return UNDEFINED.
+ Else if undefinedness of operands of STMT cause its value to be
+ undefined, then return UNDEFINED.
Else if any operands of STMT are constants, then return CONSTANT.
static ccp_lattice_t
likely_value (tree stmt)
{
- bool has_constant_operand;
+ bool has_constant_operand, has_undefined_operand, all_undefined_operands;
stmt_ann_t ann;
tree use;
ssa_op_iter iter;
return CONSTANT;
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)
{
prop_value_t *val = get_value (use);
if (val->lattice_val == UNDEFINED)
- return UNDEFINED;
+ has_undefined_operand = true;
+ else
+ all_undefined_operands = false;
if (val->lattice_val == CONSTANT)
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
+ && all_undefined_operands)
+ return UNDEFINED;
+ else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
+ && has_undefined_operand)
+ {
+ switch (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)))
+ {
+ /* Unary operators are handled with all_undefined_operands. */
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ case POINTER_PLUS_EXPR:
+ /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected.
+ Not bitwise operators, one VARYING operand may specify the
+ result completely. Not logical operators for the same reason.
+ Not COMPLEX_EXPR as one VARYING operand makes the result partly
+ not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because
+ the undefined operand may be promoted. */
+ return UNDEFINED;
+
+ default:
+ ;
+ }
+ }
+ /* If there was an UNDEFINED operand but the result may be not UNDEFINED
+ fall back to VARYING even if there were CONSTANT operands. */
+ if (has_undefined_operand)
+ return VARYING;
+
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
bool something_changed = substitute_and_fold (const_val, false);
free (const_val);
+ const_val = NULL;
return something_changed;;
}
op0 = get_value (op0)->value;
}
+ /* Conversions are useless for CCP purposes if they are
+ value-preserving. Thus the restrictions that
+ useless_type_conversion_p places for pointer type conversions do
+ not apply here. Substitution later will only substitute to
+ allowed places. */
if ((code == NOP_EXPR || code == CONVERT_EXPR)
- && tree_ssa_useless_type_conversion_1 (TREE_TYPE (rhs),
- TREE_TYPE (op0)))
+ && ((POINTER_TYPE_P (TREE_TYPE (rhs))
+ && POINTER_TYPE_P (TREE_TYPE (op0)))
+ || useless_type_conversion_p (TREE_TYPE (rhs), TREE_TYPE (op0))))
return op0;
return fold_unary (code, TREE_TYPE (rhs), op0);
}
return fold_binary (code, TREE_TYPE (rhs), op0, op1);
}
+ else if (kind == tcc_declaration)
+ return get_symbol_constant_value (rhs);
+
+ else if (kind == tcc_reference)
+ return fold_const_aggregate_ref (rhs);
+
+ /* Handle propagating invariant addresses into address operations.
+ The folding we do here matches that in tree-ssa-forwprop.c. */
+ else if (code == ADDR_EXPR)
+ {
+ tree *base;
+ base = &TREE_OPERAND (rhs, 0);
+ while (handled_component_p (*base))
+ base = &TREE_OPERAND (*base, 0);
+ if (TREE_CODE (*base) == INDIRECT_REF
+ && TREE_CODE (TREE_OPERAND (*base, 0)) == SSA_NAME)
+ {
+ 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))))
+ {
+ /* We need to return a new tree, not modify the IL or share
+ parts of it. So play some tricks to avoid manually
+ building it. */
+ tree ret, save = *base;
+ *base = TREE_OPERAND (val->value, 0);
+ ret = unshare_expr (rhs);
+ recompute_tree_invariant_for_addr_expr (ret);
+ *base = save;
+ return ret;
+ }
+ }
+ }
+
/* We may be able to fold away calls to builtin functions if their
arguments are constants. */
else if (code == CALL_EXPR
ARRAY_REF or COMPONENT_REF into constant aggregates. Return
NULL_TREE otherwise. */
-static tree
+tree
fold_const_aggregate_ref (tree t)
{
prop_value_t *value;
ctor = fold_const_aggregate_ref (base);
break;
+ case STRING_CST:
+ case CONSTRUCTOR:
+ ctor = base;
+ break;
+
default:
return NULL_TREE;
}
== MODE_INT)
&& GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1
&& compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0)
- return build_int_cst (TREE_TYPE (t), (TREE_STRING_POINTER (ctor)
- [TREE_INT_CST_LOW (idx)]));
+ return build_int_cst_type (TREE_TYPE (t),
+ (TREE_STRING_POINTER (ctor)
+ [TREE_INT_CST_LOW (idx)]));
return NULL_TREE;
}
/* Whoo-hoo! I'll fold ya baby. Yeah! */
FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
if (tree_int_cst_equal (cfield, idx))
- return cval;
+ {
+ STRIP_USELESS_TYPE_CONVERSION (cval);
+ return cval;
+ }
break;
case COMPONENT_REF:
if (cfield == field
/* FIXME: Handle bit-fields. */
&& ! DECL_BIT_FIELD (cfield))
- return cval;
+ {
+ STRIP_USELESS_TYPE_CONVERSION (cval);
+ return cval;
+ }
break;
case REALPART_EXPR:
return fold_build1 (TREE_CODE (t), TREE_TYPE (t), c);
break;
}
-
+
+ case INDIRECT_REF:
+ {
+ tree base = TREE_OPERAND (t, 0);
+ if (TREE_CODE (base) == SSA_NAME
+ && (value = get_value (base))
+ && value->lattice_val == CONSTANT
+ && TREE_CODE (value->value) == ADDR_EXPR)
+ return fold_const_aggregate_ref (TREE_OPERAND (value->value, 0));
+ break;
+ }
+
default:
break;
}
simplified = ccp_fold (stmt);
/* If the statement is likely to have a VARYING result, then do not
bother folding the statement. */
- if (likelyvalue == VARYING)
+ else if (likelyvalue == VARYING)
simplified = get_rhs (stmt);
- /* If the statement is an ARRAY_REF or COMPONENT_REF into constant
- aggregates, extract the referenced constant. Otherwise the
- statement is likely to have an UNDEFINED value, and there will be
- nothing to do. Note that fold_const_aggregate_ref returns
- NULL_TREE if the first case does not match. */
- else if (!simplified)
- simplified = fold_const_aggregate_ref (get_rhs (stmt));
is_constant = simplified && is_gimple_min_invariant (simplified);
fold_undefer_overflow_warnings (is_constant, stmt, 0);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "which is likely ");
+ switch (likelyvalue)
+ {
+ case CONSTANT:
+ fprintf (dump_file, "CONSTANT");
+ break;
+ case UNDEFINED:
+ fprintf (dump_file, "UNDEFINED");
+ break;
+ case VARYING:
+ fprintf (dump_file, "VARYING");
+ break;
+ default:;
+ }
+ fprintf (dump_file, "\n");
+ }
+
if (is_constant)
{
/* The statement produced a constant value. */
}
else
/* Evaluate the statement. */
- val = evaluate_stmt (stmt);
-
- /* If the original LHS was a VIEW_CONVERT_EXPR, modify the constant
- value to be a VIEW_CONVERT_EXPR of the old constant value.
-
- ??? Also, if this was a definition of a bitfield, we need to widen
- the constant value into the type of the destination variable. This
- should not be necessary if GCC represented bitfields properly. */
- {
- tree orig_lhs = GIMPLE_STMT_OPERAND (stmt, 0);
-
- if (TREE_CODE (orig_lhs) == VIEW_CONVERT_EXPR
- && val.lattice_val == CONSTANT)
- {
- tree w = fold_unary (VIEW_CONVERT_EXPR,
- TREE_TYPE (TREE_OPERAND (orig_lhs, 0)),
- val.value);
-
- orig_lhs = TREE_OPERAND (orig_lhs, 0);
- if (w && is_gimple_min_invariant (w))
- val.value = w;
- else
- {
- val.lattice_val = VARYING;
- val.value = NULL;
- }
- }
-
- if (val.lattice_val == CONSTANT
- && TREE_CODE (orig_lhs) == COMPONENT_REF
- && DECL_BIT_FIELD (TREE_OPERAND (orig_lhs, 1)))
- {
- tree w = widen_bitfield (val.value, TREE_OPERAND (orig_lhs, 1),
- orig_lhs);
-
- if (w && is_gimple_min_invariant (w))
- val.value = w;
- else
- {
- val.lattice_val = VARYING;
- val.value = NULL_TREE;
- val.mem_ref = NULL_TREE;
- }
- }
- }
+ val = evaluate_stmt (stmt);
retval = SSA_PROP_NOT_INTERESTING;
{
fprintf (dump_file, "\nVisiting statement:\n");
print_generic_stmt (dump_file, stmt, dump_flags);
- fprintf (dump_file, "\n");
}
if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
}
-struct tree_opt_pass pass_ccp =
+struct gimple_opt_pass pass_ccp =
{
+ {
+ GIMPLE_PASS,
"ccp", /* name */
gate_ccp, /* gate */
do_ssa_ccp, /* execute */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_dump_func | TODO_verify_ssa
- | TODO_verify_stmts | TODO_ggc_collect,/* todo_flags_finish */
- 0 /* letter */
+ | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */
+ }
};
}
-struct tree_opt_pass pass_store_ccp =
+struct gimple_opt_pass pass_store_ccp =
{
+ {
+ GIMPLE_PASS,
"store_ccp", /* name */
gate_store_ccp, /* gate */
do_ssa_store_ccp, /* execute */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_dump_func | TODO_verify_ssa
- | TODO_verify_stmts | TODO_ggc_collect,/* todo_flags_finish */
- 0 /* letter */
+ | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */
+ }
};
-/* Given a constant value VAL for bitfield FIELD, and a destination
- variable VAR, return VAL appropriately widened to fit into VAR. If
- FIELD is wider than HOST_WIDE_INT, NULL is returned. */
-
-tree
-widen_bitfield (tree val, tree field, tree var)
-{
- unsigned HOST_WIDE_INT var_size, field_size;
- tree wide_val;
- unsigned HOST_WIDE_INT mask;
- unsigned int i;
-
- /* We can only do this if the size of the type and field and VAL are
- all constants representable in HOST_WIDE_INT. */
- if (!host_integerp (TYPE_SIZE (TREE_TYPE (var)), 1)
- || !host_integerp (DECL_SIZE (field), 1)
- || !host_integerp (val, 0))
- return NULL_TREE;
-
- var_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1);
- field_size = tree_low_cst (DECL_SIZE (field), 1);
-
- /* Give up if either the bitfield or the variable are too wide. */
- if (field_size > HOST_BITS_PER_WIDE_INT || var_size > HOST_BITS_PER_WIDE_INT)
- return NULL_TREE;
-
- gcc_assert (var_size >= field_size);
-
- /* If the sign bit of the value is not set or the field's type is unsigned,
- just mask off the high order bits of the value. */
- if (DECL_UNSIGNED (field)
- || !(tree_low_cst (val, 0) & (((HOST_WIDE_INT)1) << (field_size - 1))))
- {
- /* Zero extension. Build a mask with the lower 'field_size' bits
- set and a BIT_AND_EXPR node to clear the high order bits of
- the value. */
- for (i = 0, mask = 0; i < field_size; i++)
- mask |= ((HOST_WIDE_INT) 1) << i;
-
- wide_val = fold_build2 (BIT_AND_EXPR, TREE_TYPE (var), val,
- build_int_cst (TREE_TYPE (var), mask));
- }
- else
- {
- /* Sign extension. Create a mask with the upper 'field_size'
- bits set and a BIT_IOR_EXPR to set the high order bits of the
- value. */
- for (i = 0, mask = 0; i < (var_size - field_size); i++)
- mask |= ((HOST_WIDE_INT) 1) << (var_size - i - 1);
-
- wide_val = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (var), val,
- build_int_cst (TREE_TYPE (var), mask));
- }
-
- return wide_val;
-}
-
-
/* 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. */
static tree
-maybe_fold_offset_to_array_ref (tree base, tree offset, tree orig_type)
+maybe_fold_offset_to_array_ref (tree base, tree offset, tree orig_type,
+ bool allow_negative_idx)
{
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).
if (TREE_CODE (array_type) != ARRAY_TYPE)
return NULL_TREE;
elt_type = TREE_TYPE (array_type);
- if (!lang_hooks.types_compatible_p (orig_type, elt_type))
+ if (!useless_type_conversion_p (orig_type, elt_type))
return NULL_TREE;
/* Use signed size type for intermediate computation on the index. */
low bound, if any, convert the index into that type, and add the
low bound. */
min_idx = build_int_cst (idx_type, 0);
- if (TYPE_DOMAIN (array_type))
+ domain_type = TYPE_DOMAIN (array_type);
+ if (domain_type)
{
- idx_type = TYPE_DOMAIN (array_type);
+ idx_type = domain_type;
if (TYPE_MIN_VALUE (idx_type))
min_idx = TYPE_MIN_VALUE (idx_type);
else
/* Make sure to possibly truncate late after offsetting. */
idx = fold_convert (idx_type, idx);
- return build4 (ARRAY_REF, orig_type, base, idx, NULL_TREE, NULL_TREE);
+ /* 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)
+ {
+ tree up_bound = TYPE_MAX_VALUE (domain_type);
+
+ 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;
+ }
+ 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);
}
return NULL_TREE;
/* Short-circuit silly cases. */
- if (lang_hooks.types_compatible_p (record_type, orig_type))
+ if (useless_type_conversion_p (record_type, orig_type))
return NULL_TREE;
tail_array_field = NULL_TREE;
/* Here we exactly match the offset being checked. If the types match,
then we can return that field. */
if (cmp == 0
- && lang_hooks.types_compatible_p (orig_type, field_type))
+ && useless_type_conversion_p (orig_type, field_type))
{
if (base_is_ptr)
base = build1 (INDIRECT_REF, record_type, 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);
+ 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,
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);
+ 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,
sub_offset / BITS_PER_UNIT), 1);
}
}
- if (lang_hooks.types_compatible_p (orig_type, TREE_TYPE (base))
+ if (useless_type_conversion_p (orig_type, TREE_TYPE (base))
&& integer_zerop (offset))
return base;
type = TREE_TYPE (base);
{
if (base_is_ptr)
base = build1 (INDIRECT_REF, type, base);
- ret = maybe_fold_offset_to_array_ref (base, offset, orig_type);
+ ret = maybe_fold_offset_to_array_ref (base, offset, orig_type, true);
}
return ret;
}
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
if (t)
return t;
- /* Add in any offset from a PLUS_EXPR. */
- if (TREE_CODE (base) == PLUS_EXPR)
+ /* Add in any offset from a POINTER_PLUS_EXPR. */
+ if (TREE_CODE (base) == POINTER_PLUS_EXPR)
{
tree offset2;
return NULL_TREE;
base = TREE_OPERAND (base, 0);
- offset = int_const_binop (PLUS_EXPR, offset, offset2, 1);
+ offset = fold_convert (sizetype,
+ int_const_binop (PLUS_EXPR, offset, offset2, 1));
}
if (TREE_CODE (base) == ADDR_EXPR)
/* Fold away CONST_DECL to its value, if the type is scalar. */
if (TREE_CODE (base) == CONST_DECL
- && ccp_decl_initial_min_invariant (DECL_INITIAL (base)))
+ && 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)
- return t;
+ {
+ TREE_THIS_VOLATILE (t) = volatile_p;
+ return t;
+ }
}
else
{
}
-/* A subroutine of fold_stmt_r. EXPR is a PLUS_EXPR.
+/* A subroutine of fold_stmt_r. EXPR is a POINTER_PLUS_EXPR.
A quaint feature extant in our address arithmetic is that there
can be hidden type changes here. The type of the result need
What we're after here is an expression of the form
(T *)(&array + const)
where the cast doesn't actually exist, but is implicit in the
- type of the PLUS_EXPR. We'd like to turn this into
+ type of the POINTER_PLUS_EXPR. We'd like to turn this into
&array[x]
which may be able to propagate further. */
tree ptr_type = TREE_TYPE (expr);
tree ptd_type;
tree t;
- bool subtract = (TREE_CODE (expr) == MINUS_EXPR);
- /* We're only interested in pointer arithmetic. */
- if (!POINTER_TYPE_P (ptr_type))
- return NULL_TREE;
- /* Canonicalize the integral operand to op1. */
- if (INTEGRAL_TYPE_P (TREE_TYPE (op0)))
- {
- if (subtract)
- return NULL_TREE;
- t = op0, op0 = op1, op1 = t;
- }
+ gcc_assert (TREE_CODE (expr) == POINTER_PLUS_EXPR);
+
/* It had better be a constant. */
if (TREE_CODE (op1) != INTEGER_CST)
return NULL_TREE;
array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0);
/* Update the operands for the next round, or for folding. */
- /* If we're manipulating unsigned types, then folding into negative
- values can produce incorrect results. Particularly if the type
- is smaller than the width of the pointer. */
- if (subtract
- && TYPE_UNSIGNED (TREE_TYPE (op1))
- && tree_int_cst_lt (array_idx, op1))
- return NULL;
- op1 = int_const_binop (subtract ? MINUS_EXPR : PLUS_EXPR,
+ op1 = int_const_binop (PLUS_EXPR,
array_idx, op1, 0);
- subtract = false;
op0 = array_obj;
}
- /* If we weren't able to fold the subtraction into another array reference,
- canonicalize the integer for passing to the array and component ref
- simplification functions. */
- if (subtract)
- {
- if (TYPE_UNSIGNED (TREE_TYPE (op1)))
- return NULL;
- op1 = fold_unary (NEGATE_EXPR, TREE_TYPE (op1), op1);
- /* ??? In theory fold should always produce another integer. */
- if (op1 == NULL || TREE_CODE (op1) != INTEGER_CST)
- return NULL;
- }
-
ptd_type = TREE_TYPE (ptr_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);
+ 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);
bool *inside_addr_expr_p = fold_stmt_r_data->inside_addr_expr_p;
bool *changed_p = fold_stmt_r_data->changed_p;
tree expr = *expr_p, t;
+ bool volatile_p = TREE_THIS_VOLATILE (expr);
/* ??? It'd be nice if walk_tree had a pre-order option. */
switch (TREE_CODE (expr))
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:
(TREE_OPERAND (expr, 0),
integer_zero_node,
TREE_TYPE (TREE_TYPE (expr)))))
- t = build_fold_addr_expr_with_type (t, TREE_TYPE (expr));
+ {
+ tree ptr_type = build_pointer_type (TREE_TYPE (t));
+ if (!useless_type_conversion_p (TREE_TYPE (expr), ptr_type))
+ return NULL_TREE;
+ t = build_fold_addr_expr_with_type (t, ptr_type);
+ }
break;
/* ??? Could handle more ARRAY_REFs here, as a variant of INDIRECT_REF.
return t;
*walk_subtrees = 0;
- /* Set TREE_INVARIANT properly so that the value is properly
- considered constant, and so gets propagated as expected. */
+ /* 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 PLUS_EXPR:
- case MINUS_EXPR:
+ case POINTER_PLUS_EXPR:
t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL);
if (t)
return t;
if (t)
{
+ /* Preserve volatileness of the original expression. */
+ TREE_THIS_VOLATILE (t) = volatile_p;
*expr_p = t;
*changed_p = true;
}
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)
{
return changed;
}
\f
+/* 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 (basic_block bb, tree call, block_stmt_iterator i)
+{
+ tree stack_save, stmt, callee;
+
+ if (TREE_CODE (call) != CALL_EXPR
+ || call_expr_nargs (call) != 1
+ || TREE_CODE (CALL_EXPR_ARG (call, 0)) != SSA_NAME
+ || !POINTER_TYPE_P (TREE_TYPE (CALL_EXPR_ARG (call, 0))))
+ return NULL_TREE;
+
+ for (bsi_next (&i); !bsi_end_p (i); bsi_next (&i))
+ {
+ tree call;
+
+ stmt = bsi_stmt (i);
+ if (TREE_CODE (stmt) == ASM_EXPR)
+ return NULL_TREE;
+ call = get_call_expr_in (stmt);
+ if (call == NULL)
+ continue;
+
+ callee = get_callee_fndecl (call);
+ if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL)
+ return NULL_TREE;
+
+ if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE)
+ break;
+ }
+
+ if (bsi_end_p (i)
+ && (! single_succ_p (bb)
+ || single_succ_edge (bb)->dest != EXIT_BLOCK_PTR))
+ return NULL_TREE;
+
+ stack_save = SSA_NAME_DEF_STMT (CALL_EXPR_ARG (call, 0));
+ if (TREE_CODE (stack_save) != GIMPLE_MODIFY_STMT
+ || GIMPLE_STMT_OPERAND (stack_save, 0) != CALL_EXPR_ARG (call, 0)
+ || TREE_CODE (GIMPLE_STMT_OPERAND (stack_save, 1)) != CALL_EXPR
+ || tree_could_throw_p (stack_save)
+ || !has_single_use (CALL_EXPR_ARG (call, 0)))
+ return NULL_TREE;
+
+ callee = get_callee_fndecl (GIMPLE_STMT_OPERAND (stack_save, 1));
+ if (!callee
+ || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL
+ || DECL_FUNCTION_CODE (callee) != BUILT_IN_STACK_SAVE
+ || call_expr_nargs (GIMPLE_STMT_OPERAND (stack_save, 1)) != 0)
+ return NULL_TREE;
+
+ stmt = stack_save;
+ push_stmt_changes (&stmt);
+ if (!set_rhs (&stmt,
+ build_int_cst (TREE_TYPE (CALL_EXPR_ARG (call, 0)), 0)))
+ {
+ discard_stmt_changes (&stmt);
+ return NULL_TREE;
+ }
+ gcc_assert (stmt == stack_save);
+ pop_stmt_changes (&stmt);
+
+ return integer_zero_node;
+}
+\f
+/* 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 (tree call)
+{
+ tree callee, lhs, rhs;
+ bool va_list_simple_ptr;
+
+ if (TREE_CODE (call) != CALL_EXPR)
+ return NULL_TREE;
+
+ va_list_simple_ptr = POINTER_TYPE_P (va_list_type_node)
+ && (TREE_TYPE (va_list_type_node) == void_type_node
+ || TREE_TYPE (va_list_type_node) == char_type_node);
+
+ callee = get_callee_fndecl (call);
+ 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 (call_expr_nargs (call) != 2)
+ return NULL_TREE;
+
+ lhs = CALL_EXPR_ARG (call, 0);
+ if (!POINTER_TYPE_P (TREE_TYPE (lhs))
+ || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
+ != TYPE_MAIN_VARIANT (va_list_type_node))
+ 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 (call_expr_nargs (call) != 2)
+ return NULL_TREE;
+
+ lhs = CALL_EXPR_ARG (call, 0);
+ if (!POINTER_TYPE_P (TREE_TYPE (lhs))
+ || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
+ != TYPE_MAIN_VARIANT (va_list_type_node))
+ return NULL_TREE;
+
+ lhs = build_fold_indirect_ref (lhs);
+ rhs = CALL_EXPR_ARG (call, 1);
+ if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs))
+ != TYPE_MAIN_VARIANT (va_list_type_node))
+ return NULL_TREE;
+
+ rhs = fold_convert (TREE_TYPE (lhs), rhs);
+ return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
+
+ case BUILT_IN_VA_END:
+ return integer_zero_node;
+
+ default:
+ gcc_unreachable ();
+ }
+}
+\f
/* Convert EXPR into a GIMPLE value suitable for substitution on the
RHS of an assignment. Insert the necessary statements before
iterator *SI_P.
{
bool cfg_changed = false;
basic_block bb;
+ unsigned int todoflags = 0;
+
FOR_EACH_BB (bb)
{
block_stmt_iterator i;
fcode = DECL_FUNCTION_CODE (callee);
result = ccp_fold_builtin (*stmtp, call);
+
+ if (result)
+ gimple_remove_stmt_histograms (cfun, *stmtp);
+
if (!result)
switch (DECL_FUNCTION_CODE (callee))
{
result = integer_zero_node;
break;
+ case BUILT_IN_STACK_RESTORE:
+ result = optimize_stack_restore (bb, *stmtp, i);
+ if (result)
+ break;
+ bsi_next (&i);
+ continue;
+
+ case BUILT_IN_VA_START:
+ case BUILT_IN_VA_END:
+ case BUILT_IN_VA_COPY:
+ /* These shouldn't be folded before pass_stdarg. */
+ result = optimize_stdarg_builtin (*stmtp);
+ if (result)
+ break;
+ /* FALLTHRU */
+
default:
bsi_next (&i);
continue;
{
bool ok = set_rhs (stmtp, result);
gcc_assert (ok);
+ todoflags |= TODO_rebuild_alias;
}
}
bsi_next (&i);
}
}
-
+
/* Delete unreachable blocks. */
- return cfg_changed ? TODO_cleanup_cfg : 0;
+ if (cfg_changed)
+ todoflags |= TODO_cleanup_cfg;
+
+ return todoflags;
}
-struct tree_opt_pass pass_fold_builtins =
+struct gimple_opt_pass pass_fold_builtins =
{
+ {
+ GIMPLE_PASS,
"fab", /* name */
NULL, /* gate */
execute_fold_all_builtins, /* execute */
0, /* todo_flags_start */
TODO_dump_func
| TODO_verify_ssa
- | TODO_update_ssa, /* todo_flags_finish */
- 0 /* letter */
+ | TODO_update_ssa /* todo_flags_finish */
+ }
};
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