/* Fold a constant sub-tree into a single node for C-compiler
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+ 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
Free Software Foundation, Inc.
This file is part of GCC.
/* If both types don't have the same signedness, then we can't consider
them equal. We must check this before the STRIP_NOPS calls
- because they may change the signedness of the arguments. */
- if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
+ because they may change the signedness of the arguments. As pointers
+ strictly don't have a signedness, require either two pointers or
+ two non-pointers as well. */
+ if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1))
+ || POINTER_TYPE_P (TREE_TYPE (arg0)) != POINTER_TYPE_P (TREE_TYPE (arg1)))
return 0;
/* If both types don't have the same precision, then it is not safe
/* Two conversions are equal only if signedness and modes match. */
switch (TREE_CODE (arg0))
{
- case NOP_EXPR:
- case CONVERT_EXPR:
+ CASE_CONVERT:
case FIX_TRUNC_EXPR:
if (TYPE_UNSIGNED (TREE_TYPE (arg0))
!= TYPE_UNSIGNED (TREE_TYPE (arg1)))
/* We are interested in the bare arrangement of bits, so strip everything
that doesn't affect the machine mode. However, record the type of the
outermost expression if it may matter below. */
- if (TREE_CODE (exp) == NOP_EXPR
- || TREE_CODE (exp) == CONVERT_EXPR
+ if (CONVERT_EXPR_P (exp)
|| TREE_CODE (exp) == NON_LVALUE_EXPR)
outer_type = TREE_TYPE (exp);
STRIP_NOPS (exp);
exp = arg0;
continue;
- case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
+ CASE_CONVERT: case NON_LVALUE_EXPR:
if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
break;
fold_convert (ctype, c), 0);
break;
- case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
+ CASE_CONVERT: case NON_LVALUE_EXPR:
/* If op0 is an expression ... */
if ((COMPARISON_CLASS_P (op0)
|| UNARY_CLASS_P (op0)
/* If these are the same operation types, we can associate them
assuming no overflow. */
if (tcode == code
- && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
- fold_convert (ctype, c), 0))
+ && 0 != (t1 = int_const_binop (MULT_EXPR, fold_convert (ctype, op1),
+ fold_convert (ctype, c), 1))
+ && 0 != (t1 = force_fit_type_double (ctype, TREE_INT_CST_LOW (t1),
+ TREE_INT_CST_HIGH (t1),
+ (TYPE_UNSIGNED (ctype)
+ && tcode != MULT_EXPR) ? -1 : 1,
+ TREE_OVERFLOW (t1)))
&& !TREE_OVERFLOW (t1))
return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
tree arg0_inner;
tree inner_type, outer_type;
- if (TREE_CODE (arg0) != NOP_EXPR
- && TREE_CODE (arg0) != CONVERT_EXPR)
+ if (!CONVERT_EXPR_P (arg0))
return NULL_TREE;
outer_type = TREE_TYPE (arg0);
return NULL_TREE;
if (TREE_CODE (arg1) != INTEGER_CST
- && !((TREE_CODE (arg1) == NOP_EXPR
- || TREE_CODE (arg1) == CONVERT_EXPR)
+ && !(CONVERT_EXPR_P (arg1)
&& TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
return NULL_TREE;
- if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
+ if ((TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
+ || POINTER_TYPE_P (inner_type) != POINTER_TYPE_P (outer_type))
&& code != NE_EXPR
&& code != EQ_EXPR)
return NULL_TREE;
else
{
/* Try if delta is a multiple of step. */
- tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
+ tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, op1, step);
if (! tmp)
continue;
delta = tmp;
return fold_convert (type, op0);
return NULL_TREE;
- case NOP_EXPR:
+ CASE_CONVERT:
case FLOAT_EXPR:
- case CONVERT_EXPR:
case FIX_TRUNC_EXPR:
if (TREE_TYPE (op0) == type)
return op0;
TREE_OPERAND (op0, 1));
/* Handle cases of two conversions in a row. */
- if (TREE_CODE (op0) == NOP_EXPR
- || TREE_CODE (op0) == CONVERT_EXPR)
+ if (CONVERT_EXPR_P (op0))
{
tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
tree inter_type = TREE_TYPE (op0);
/* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
constants (if x has signed type, the sign bit cannot be set
in c). This folds extension into the BIT_AND_EXPR. */
- if (INTEGRAL_TYPE_P (type)
- && TREE_CODE (type) != BOOLEAN_TYPE
+ if (TREE_CODE (type) == INTEGER_TYPE
&& TREE_CODE (op0) == BIT_AND_EXPR
&& TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
{
if (INTEGRAL_TYPE_P (type)
&& TREE_CODE (op0) == BIT_NOT_EXPR
&& INTEGRAL_TYPE_P (TREE_TYPE (op0))
- && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
- || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
+ && CONVERT_EXPR_P (TREE_OPERAND (op0, 0))
&& TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
{
tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
return fold_convert (type, op0);
/* Strip inner integral conversions that do not change the precision. */
- if ((TREE_CODE (op0) == NOP_EXPR
- || TREE_CODE (op0) == CONVERT_EXPR)
+ if (CONVERT_EXPR_P (op0)
&& (INTEGRAL_TYPE_P (TREE_TYPE (op0))
|| POINTER_TYPE_P (TREE_TYPE (op0)))
&& (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
static bool
pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
{
- tree size;
unsigned HOST_WIDE_INT offset_low, total_low;
- HOST_WIDE_INT offset_high, total_high;
+ HOST_WIDE_INT size, offset_high, total_high;
if (!POINTER_TYPE_P (TREE_TYPE (base)))
return true;
if (bitpos < 0)
return true;
- size = size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
- if (size == NULL_TREE || TREE_CODE (size) != INTEGER_CST)
- return true;
-
- /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
- array. */
- if (TREE_CODE (base) == ADDR_EXPR)
- {
- tree base_size = size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
- if (base_size != NULL_TREE
- && TREE_CODE (base_size) == INTEGER_CST
- && INT_CST_LT_UNSIGNED (size, base_size))
- size = base_size;
- }
-
if (offset == NULL_TREE)
{
offset_low = 0;
true))
return true;
- if ((unsigned HOST_WIDE_INT) total_high
- < (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (size))
- return false;
- if ((unsigned HOST_WIDE_INT) total_high
- > (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (size))
+ if (total_high != 0)
return true;
- return total_low > TREE_INT_CST_LOW (size);
+
+ size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
+ if (size <= 0)
+ return true;
+
+ /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
+ array. */
+ if (TREE_CODE (base) == ADDR_EXPR)
+ {
+ HOST_WIDE_INT base_size;
+
+ base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
+ if (base_size > 0 && size < base_size)
+ size = base_size;
+ }
+
+ return total_low > (unsigned HOST_WIDE_INT) size;
}
/* Subroutine of fold_binary. This routine performs all of the
}
if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
- && (TREE_CODE (arg0) == NOP_EXPR
- || TREE_CODE (arg0) == CONVERT_EXPR))
+ && CONVERT_EXPR_P (arg0))
{
/* If we are widening one operand of an integer comparison,
see if the other operand is similarly being widened. Perhaps we
safe for every expression, except for a comparison expression
because its signedness is derived from its operands. So, in
the latter case, only strip conversions that don't change the
- signedness.
+ signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
+ preserved.
Note that this is done as an internal manipulation within the
constant folder, in order to find the simplest representation
cases, the appropriate type conversions should be put back in
the tree that will get out of the constant folder. */
- if (kind == tcc_comparison)
+ if (kind == tcc_comparison || code == MIN_EXPR || code == MAX_EXPR)
{
STRIP_SIGN_NOPS (arg0);
STRIP_SIGN_NOPS (arg1);
return fold_build2 (LSHIFT_EXPR, type, op1,
TREE_OPERAND (arg0, 1));
+ /* (A + A) * C -> A * 2 * C */
+ if (TREE_CODE (arg0) == PLUS_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg0, 1), 0))
+ return fold_build2 (MULT_EXPR, type,
+ omit_one_operand (type, TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg0, 1)),
+ fold_build2 (MULT_EXPR, type,
+ build_int_cst (type, 2) , arg1));
+
strict_overflow_p = false;
if (TREE_CODE (arg1) == INTEGER_CST
&& 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
if ((code == LT_EXPR || code == GE_EXPR)
&& TYPE_UNSIGNED (TREE_TYPE (arg0))
- && (TREE_CODE (arg1) == NOP_EXPR
- || TREE_CODE (arg1) == CONVERT_EXPR)
+ && CONVERT_EXPR_P (arg1)
&& TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
&& integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
return
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