static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
tree);
static tree fold_range_test (tree);
+static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
static tree unextend (tree, int, int, tree);
static tree fold_truthop (enum tree_code, tree, tree, tree);
static tree optimize_minmax_comparison (tree);
|| TREE_CODE (orig) == ERROR_MARK)
return error_mark_node;
- if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
+ if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
+ || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
+ TYPE_MAIN_VARIANT (orig)))
return fold (build1 (NOP_EXPR, type, arg));
if (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type)
return fold (build1 (NOP_EXPR, type, arg));
}
else if (VOID_TYPE_P (type))
- return fold (build1 (CONVERT_EXPR, type, arg));
+ return fold (build1 (CONVERT_EXPR, type, fold_ignored_result (arg)));
abort ();
}
\f
case COMPONENT_REF:
case INDIRECT_REF:
case ARRAY_REF:
- case BIT_FIELD_REF:
- case BUFFER_REF:
case ARRAY_RANGE_REF:
- case VTABLE_REF:
+ case BIT_FIELD_REF:
+ case OBJ_TYPE_REF:
case REALPART_EXPR:
case IMAGPART_EXPR:
case BIND_EXPR:
case MIN_EXPR:
case MAX_EXPR:
- case RTL_EXPR:
break;
default:
}
else if (flag_trapping_math)
{
- /* Check that the original operation and the optimized ones will trap
+ /* Check that the original operation and the optimized ones will trap
under the same condition. */
bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
&& (lcompcode != COMPCODE_EQ)
case '<':
case '2':
- if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
- && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
- 0))
+ if (operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0), flags)
+ && operand_equal_p (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1), flags))
return 1;
/* For commutative ops, allow the other order. */
switch (TREE_CODE (arg0))
{
case INDIRECT_REF:
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
return operand_equal_p (TREE_OPERAND (arg0, 0),
TREE_OPERAND (arg1, 0), flags);
return operand_equal_p (TREE_OPERAND (arg0, 0),
TREE_OPERAND (arg1, 0), flags);
- case RTL_EXPR:
- return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
+ case TRUTH_ANDIF_EXPR:
+ case TRUTH_ORIF_EXPR:
+ return operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0), flags)
+ && operand_equal_p (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1), flags);
+
+ case TRUTH_AND_EXPR:
+ case TRUTH_OR_EXPR:
+ case TRUTH_XOR_EXPR:
+ return (operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0), flags)
+ && operand_equal_p (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1), flags))
+ || (operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 1), flags)
+ && operand_equal_p (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 0), flags));
case CALL_EXPR:
/* If the CALL_EXPRs call different functions, then they
|| code == COMPOUND_EXPR))
class = '2';
- else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
+ else if (class == 'e' && code == SAVE_EXPR
&& ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
{
/* If we've already found a CVAL1 or CVAL2, this expression is
tree t = fold_convert (type, result);
if (TREE_SIDE_EFFECTS (omitted))
- return build2 (COMPOUND_EXPR, type, omitted, t);
+ return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
return non_lvalue (t);
}
tree t = fold_convert (type, result);
if (TREE_SIDE_EFFECTS (omitted))
- return build2 (COMPOUND_EXPR, type, omitted, t);
+ return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
return pedantic_non_lvalue (t);
}
/* If the number of bits in the reference is the same as the bitsize of
the outer type, then the outer type gives the signedness. Otherwise
(in case of a small bitfield) the signedness is unchanged. */
- if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
+ if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
*punsignedp = TYPE_UNSIGNED (outer_type);
/* Compute the mask to access the bitfield. */
make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
{
enum tree_code code;
- tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
- tree orig_type = NULL_TREE;
+ tree arg0 = NULL_TREE, arg1 = NULL_TREE;
+ tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
int in_p, n_in_p;
tree low, high, n_low, n_high;
while (1)
{
code = TREE_CODE (exp);
+ exp_type = TREE_TYPE (exp);
if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
{
if (TREE_CODE_CLASS (code) == '<'
|| TREE_CODE_CLASS (code) == '1'
|| TREE_CODE_CLASS (code) == '2')
- type = TREE_TYPE (arg0);
+ arg0_type = TREE_TYPE (arg0);
if (TREE_CODE_CLASS (code) == '2'
|| TREE_CODE_CLASS (code) == '<'
|| (TREE_CODE_CLASS (code) == 'e'
arg1 = TREE_OPERAND (exp, 1);
}
- /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
- lose a cast by accident. */
- if (type != NULL_TREE && orig_type == NULL_TREE)
- orig_type = type;
-
switch (code)
{
case TRUTH_NOT_EXPR:
abort ();
}
- exp = arg0;
-
/* If this is an unsigned comparison, we also know that EXP is
greater than or equal to zero. We base the range tests we make
on that fact, so we record it here so we can parse existing
- range tests. */
- if (TYPE_UNSIGNED (type) && (low == 0 || high == 0))
+ range tests. We test arg0_type since often the return type
+ of, e.g. EQ_EXPR, is boolean. */
+ if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
{
if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
- 1, fold_convert (type, integer_zero_node),
+ 1, fold_convert (arg0_type, integer_zero_node),
NULL_TREE))
break;
in_p = ! in_p;
high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
integer_one_node, 0);
- low = fold_convert (type, integer_zero_node);
+ low = fold_convert (arg0_type, integer_zero_node);
}
}
+
+ exp = arg0;
continue;
case NEGATE_EXPR:
/* (-x) IN [a,b] -> x in [-b, -a] */
- n_low = range_binop (MINUS_EXPR, type,
- fold_convert (type, integer_zero_node),
+ n_low = range_binop (MINUS_EXPR, exp_type,
+ fold_convert (exp_type, integer_zero_node),
0, high, 1);
- n_high = range_binop (MINUS_EXPR, type,
- fold_convert (type, integer_zero_node),
+ n_high = range_binop (MINUS_EXPR, exp_type,
+ fold_convert (exp_type, integer_zero_node),
0, low, 0);
low = n_low, high = n_high;
exp = arg0;
case BIT_NOT_EXPR:
/* ~ X -> -X - 1 */
- exp = build2 (MINUS_EXPR, type, negate_expr (arg0),
- fold_convert (type, integer_one_node));
+ exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
+ fold_convert (exp_type, integer_one_node));
continue;
case PLUS_EXPR: case MINUS_EXPR:
the bounds don't overflow. For unsigned, overflow is defined
and this is exactly the right thing. */
n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
- type, low, 0, arg1, 0);
+ arg0_type, low, 0, arg1, 0);
n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
- type, high, 1, arg1, 0);
+ arg0_type, high, 1, arg1, 0);
if ((n_low != 0 && TREE_OVERFLOW (n_low))
|| (n_high != 0 && TREE_OVERFLOW (n_high)))
break;
value thus making n_high < n_low, and normalize it. */
if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
{
- low = range_binop (PLUS_EXPR, type, n_high, 0,
+ low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
integer_one_node, 0);
- high = range_binop (MINUS_EXPR, type, n_low, 0,
+ high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
integer_one_node, 0);
/* If the range is of the form +/- [ x+1, x ], we won't
continue;
case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
- if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
+ if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
break;
- if (! INTEGRAL_TYPE_P (type)
- || (low != 0 && ! int_fits_type_p (low, type))
- || (high != 0 && ! int_fits_type_p (high, type)))
+ if (! INTEGRAL_TYPE_P (arg0_type)
+ || (low != 0 && ! int_fits_type_p (low, arg0_type))
+ || (high != 0 && ! int_fits_type_p (high, arg0_type)))
break;
n_low = low, n_high = high;
if (n_low != 0)
- n_low = fold_convert (type, n_low);
+ n_low = fold_convert (arg0_type, n_low);
if (n_high != 0)
- n_high = fold_convert (type, n_high);
+ n_high = fold_convert (arg0_type, n_high);
- /* If we're converting from an unsigned to a signed type,
- we will be doing the comparison as unsigned. The tests above
- have already verified that LOW and HIGH are both positive.
- So we have to make sure that the original unsigned value will
- be interpreted as positive. */
- if (TYPE_UNSIGNED (type) && ! TYPE_UNSIGNED (TREE_TYPE (exp)))
+ /* If we're converting arg0 from an unsigned type, to exp,
+ a signed type, we will be doing the comparison as unsigned.
+ The tests above have already verified that LOW and HIGH
+ are both positive.
+
+ So we have to ensure that we will handle large unsigned
+ values the same way that the current signed bounds treat
+ negative values. */
+
+ if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
{
- tree equiv_type = lang_hooks.types.type_for_mode
- (TYPE_MODE (type), 1);
tree high_positive;
+ tree equiv_type = lang_hooks.types.type_for_mode
+ (TYPE_MODE (arg0_type), 1);
/* A range without an upper bound is, naturally, unbounded.
Since convert would have cropped a very large value, use
the max value for the destination type. */
high_positive
= TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
- : TYPE_MAX_VALUE (type);
+ : TYPE_MAX_VALUE (arg0_type);
- if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
- high_positive = fold (build2 (RSHIFT_EXPR, type,
- fold_convert (type,
+ if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
+ high_positive = fold (build2 (RSHIFT_EXPR, arg0_type,
+ fold_convert (arg0_type,
high_positive),
- fold_convert (type,
+ fold_convert (arg0_type,
integer_one_node)));
/* If the low bound is specified, "and" the range with the
{
if (! merge_ranges (&n_in_p, &n_low, &n_high,
1, n_low, n_high, 1,
- fold_convert (type, integer_zero_node),
+ fold_convert (arg0_type, integer_zero_node),
high_positive))
break;
that will be interpreted as negative. */
if (! merge_ranges (&n_in_p, &n_low, &n_high,
0, n_low, n_high, 1,
- fold_convert (type, integer_zero_node),
+ fold_convert (arg0_type, integer_zero_node),
high_positive))
break;
\f
/* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
type, TYPE, return an expression to test if EXP is in (or out of, depending
- on IN_P) the range. */
+ on IN_P) the range. Return 0 if the test couldn't be created. */
static tree
build_range_check (tree type, tree exp, int in_p, tree low, tree high)
tree etype = TREE_TYPE (exp);
tree value;
- if (! in_p
- && (0 != (value = build_range_check (type, exp, 1, low, high))))
- return invert_truthvalue (value);
+ if (! in_p)
+ {
+ value = build_range_check (type, exp, 1, low, high);
+ if (value != 0)
+ return invert_truthvalue (value);
+
+ return 0;
+ }
if (low == 0 && high == 0)
return fold_convert (type, integer_one_node);
}
}
- if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
- && ! TREE_OVERFLOW (value))
+ value = const_binop (MINUS_EXPR, high, low, 0);
+ if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
+ {
+ tree utype, minv, maxv;
+
+ /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
+ for the type in question, as we rely on this here. */
+ switch (TREE_CODE (etype))
+ {
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ case CHAR_TYPE:
+ utype = lang_hooks.types.unsigned_type (etype);
+ maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
+ maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
+ integer_one_node, 1);
+ minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
+ if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
+ minv, 1, maxv, 1)))
+ {
+ etype = utype;
+ high = fold_convert (etype, high);
+ low = fold_convert (etype, low);
+ exp = fold_convert (etype, exp);
+ value = const_binop (MINUS_EXPR, high, low, 0);
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (value != 0 && ! TREE_OVERFLOW (value))
return build_range_check (type,
fold (build2 (MINUS_EXPR, etype, exp, low)),
1, fold_convert (etype, integer_zero_node),
1, low1, 0)))
in_p = 0, low = low0, high = high1;
else
- return 0;
+ {
+ /* Canonicalize - [min, x] into - [-, x]. */
+ if (low0 && TREE_CODE (low0) == INTEGER_CST)
+ switch (TREE_CODE (TREE_TYPE (low0)))
+ {
+ case ENUMERAL_TYPE:
+ if (TYPE_PRECISION (TREE_TYPE (low0))
+ != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
+ break;
+ /* FALLTHROUGH */
+ case INTEGER_TYPE:
+ case CHAR_TYPE:
+ if (tree_int_cst_equal (low0,
+ TYPE_MIN_VALUE (TREE_TYPE (low0))))
+ low0 = 0;
+ break;
+ case POINTER_TYPE:
+ if (TYPE_UNSIGNED (TREE_TYPE (low0))
+ && integer_zerop (low0))
+ low0 = 0;
+ break;
+ default:
+ break;
+ }
+
+ /* Canonicalize - [x, max] into - [x, -]. */
+ if (high1 && TREE_CODE (high1) == INTEGER_CST)
+ switch (TREE_CODE (TREE_TYPE (high1)))
+ {
+ case ENUMERAL_TYPE:
+ if (TYPE_PRECISION (TREE_TYPE (high1))
+ != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
+ break;
+ /* FALLTHROUGH */
+ case INTEGER_TYPE:
+ case CHAR_TYPE:
+ if (tree_int_cst_equal (high1,
+ TYPE_MAX_VALUE (TREE_TYPE (high1))))
+ high1 = 0;
+ break;
+ case POINTER_TYPE:
+ if (TYPE_UNSIGNED (TREE_TYPE (high1))
+ && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
+ high1, 1,
+ integer_one_node, 1)))
+ high1 = 0;
+ break;
+ default:
+ break;
+ }
+
+ /* The ranges might be also adjacent between the maximum and
+ minimum values of the given type. For
+ - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
+ return + [x + 1, y - 1]. */
+ if (low0 == 0 && high1 == 0)
+ {
+ low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
+ integer_one_node, 1);
+ high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
+ integer_one_node, 0);
+ if (low == 0 || high == 0)
+ return 0;
+
+ in_p = 1;
+ }
+ else
+ return 0;
+ }
}
else if (subset)
in_p = 0, low = low0, high = high0;
return 1;
}
\f
+
+/* Subroutine of fold, looking inside expressions of the form
+ A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
+ of the COND_EXPR. This function is being used also to optimize
+ A op B ? C : A, by reversing the comparison first.
+
+ Return a folded expression whose code is not a COND_EXPR
+ anymore, or NULL_TREE if no folding opportunity is found. */
+
+static tree
+fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
+{
+ enum tree_code comp_code = TREE_CODE (arg0);
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ tree arg1_type = TREE_TYPE (arg1);
+ tree tem;
+
+ STRIP_NOPS (arg1);
+ STRIP_NOPS (arg2);
+
+ /* If we have A op 0 ? A : -A, consider applying the following
+ transformations:
+
+ A == 0? A : -A same as -A
+ A != 0? A : -A same as A
+ A >= 0? A : -A same as abs (A)
+ A > 0? A : -A same as abs (A)
+ A <= 0? A : -A same as -abs (A)
+ A < 0? A : -A same as -abs (A)
+
+ None of these transformations work for modes with signed
+ zeros. If A is +/-0, the first two transformations will
+ change the sign of the result (from +0 to -0, or vice
+ versa). The last four will fix the sign of the result,
+ even though the original expressions could be positive or
+ negative, depending on the sign of A.
+
+ Note that all these transformations are correct if A is
+ NaN, since the two alternatives (A and -A) are also NaNs. */
+ if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
+ ? real_zerop (arg01)
+ : integer_zerop (arg01))
+ && TREE_CODE (arg2) == NEGATE_EXPR
+ && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
+ switch (comp_code)
+ {
+ case EQ_EXPR:
+ tem = fold_convert (arg1_type, arg1);
+ return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
+ case NE_EXPR:
+ return pedantic_non_lvalue (fold_convert (type, arg1));
+ case GE_EXPR:
+ case GT_EXPR:
+ if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
+ arg1 = fold_convert (lang_hooks.types.signed_type
+ (TREE_TYPE (arg1)), arg1);
+ tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
+ return pedantic_non_lvalue (fold_convert (type, tem));
+ case LE_EXPR:
+ case LT_EXPR:
+ if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
+ arg1 = fold_convert (lang_hooks.types.signed_type
+ (TREE_TYPE (arg1)), arg1);
+ tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
+ return negate_expr (fold_convert (type, tem));
+ default:
+ abort ();
+ }
+
+ /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
+ A == 0 ? A : 0 is always 0 unless A is -0. Note that
+ both transformations are correct when A is NaN: A != 0
+ is then true, and A == 0 is false. */
+
+ if (integer_zerop (arg01) && integer_zerop (arg2))
+ {
+ if (comp_code == NE_EXPR)
+ return pedantic_non_lvalue (fold_convert (type, arg1));
+ else if (comp_code == EQ_EXPR)
+ return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
+ }
+
+ /* Try some transformations of A op B ? A : B.
+
+ A == B? A : B same as B
+ A != B? A : B same as A
+ A >= B? A : B same as max (A, B)
+ A > B? A : B same as max (B, A)
+ A <= B? A : B same as min (A, B)
+ A < B? A : B same as min (B, A)
+
+ As above, these transformations don't work in the presence
+ of signed zeros. For example, if A and B are zeros of
+ opposite sign, the first two transformations will change
+ the sign of the result. In the last four, the original
+ expressions give different results for (A=+0, B=-0) and
+ (A=-0, B=+0), but the transformed expressions do not.
+
+ The first two transformations are correct if either A or B
+ is a NaN. In the first transformation, the condition will
+ be false, and B will indeed be chosen. In the case of the
+ second transformation, the condition A != B will be true,
+ and A will be chosen.
+
+ The conversions to max() and min() are not correct if B is
+ a number and A is not. The conditions in the original
+ expressions will be false, so all four give B. The min()
+ and max() versions would give a NaN instead. */
+ if (operand_equal_for_comparison_p (arg01, arg2, arg00))
+ {
+ tree comp_op0 = arg00;
+ tree comp_op1 = arg01;
+ tree comp_type = TREE_TYPE (comp_op0);
+
+ /* Avoid adding NOP_EXPRs in case this is an lvalue. */
+ if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
+ {
+ comp_type = type;
+ comp_op0 = arg1;
+ comp_op1 = arg2;
+ }
+
+ switch (comp_code)
+ {
+ case EQ_EXPR:
+ return pedantic_non_lvalue (fold_convert (type, arg2));
+ case NE_EXPR:
+ return pedantic_non_lvalue (fold_convert (type, arg1));
+ case LE_EXPR:
+ case LT_EXPR:
+ /* In C++ a ?: expression can be an lvalue, so put the
+ operand which will be used if they are equal first
+ so that we can convert this back to the
+ corresponding COND_EXPR. */
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
+ return pedantic_non_lvalue (
+ fold_convert (type, fold (build2 (MIN_EXPR, comp_type,
+ (comp_code == LE_EXPR
+ ? comp_op0 : comp_op1),
+ (comp_code == LE_EXPR
+ ? comp_op1 : comp_op0)))));
+ break;
+ case GE_EXPR:
+ case GT_EXPR:
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
+ return pedantic_non_lvalue (
+ fold_convert (type, fold (build2 (MAX_EXPR, comp_type,
+ (comp_code == GE_EXPR
+ ? comp_op0 : comp_op1),
+ (comp_code == GE_EXPR
+ ? comp_op1 : comp_op0)))));
+ break;
+ default:
+ abort ();
+ }
+ }
+
+ /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
+ we might still be able to simplify this. For example,
+ if C1 is one less or one more than C2, this might have started
+ out as a MIN or MAX and been transformed by this function.
+ Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
+
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (arg01) == INTEGER_CST
+ && TREE_CODE (arg2) == INTEGER_CST)
+ switch (comp_code)
+ {
+ case EQ_EXPR:
+ /* We can replace A with C1 in this case. */
+ arg1 = fold_convert (type, arg01);
+ return fold (build3 (COND_EXPR, type, arg0, arg1, arg2));
+
+ case LT_EXPR:
+ /* If C1 is C2 + 1, this is min(A, C2). */
+ if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
+ OEP_ONLY_CONST)
+ && operand_equal_p (arg01,
+ const_binop (PLUS_EXPR, arg2,
+ integer_one_node, 0),
+ OEP_ONLY_CONST))
+ return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
+ type, arg1, arg2)));
+ break;
+
+ case LE_EXPR:
+ /* If C1 is C2 - 1, this is min(A, C2). */
+ if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
+ OEP_ONLY_CONST)
+ && operand_equal_p (arg01,
+ const_binop (MINUS_EXPR, arg2,
+ integer_one_node, 0),
+ OEP_ONLY_CONST))
+ return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
+ type, arg1, arg2)));
+ break;
+
+ case GT_EXPR:
+ /* If C1 is C2 - 1, this is max(A, C2). */
+ if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
+ OEP_ONLY_CONST)
+ && operand_equal_p (arg01,
+ const_binop (MINUS_EXPR, arg2,
+ integer_one_node, 0),
+ OEP_ONLY_CONST))
+ return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
+ type, arg1, arg2)));
+ break;
+
+ case GE_EXPR:
+ /* If C1 is C2 + 1, this is max(A, C2). */
+ if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
+ OEP_ONLY_CONST)
+ && operand_equal_p (arg01,
+ const_binop (PLUS_EXPR, arg2,
+ integer_one_node, 0),
+ OEP_ONLY_CONST))
+ return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
+ type, arg1, arg2)));
+ break;
+ case NE_EXPR:
+ break;
+ default:
+ abort ();
+ }
+
+ return NULL_TREE;
+}
+
+
+\f
#ifndef RANGE_TEST_NON_SHORT_CIRCUIT
#define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
#endif
{
if (type == integer_type_node)
return value ? integer_one_node : integer_zero_node;
+ else if (type == boolean_type_node)
+ return value ? boolean_true_node : boolean_false_node;
else if (TREE_CODE (type) == BOOLEAN_TYPE)
return lang_hooks.truthvalue_conversion (value ? integer_one_node
: integer_zero_node);
not appropriate if we are in gimple form. */
if (in_gimple_form)
return NULL_TREE;
-
+
temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
arg0, build_real (TREE_TYPE (arg0), max)));
return fold (build1 (TRUTH_NOT_EXPR, type, temp));
equality/inequality test, then return a simplified form of
the test using shifts and logical operations. Otherwise return
NULL. TYPE is the desired result type. */
-
+
tree
fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
tree result_type)
arg1 = TREE_OPERAND (arg0, 1);
arg0 = TREE_OPERAND (arg0, 0);
- /* This requires us to invert the code. */
+ /* This requires us to invert the code. */
code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
}
int ops_unsigned;
tree signed_type, unsigned_type, intermediate_type;
tree arg00;
-
+
/* If we have (A & C) != 0 where C is the sign bit of A, convert
this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
fold_convert (stype, integer_zero_node)));
}
- /* Otherwise we have (A & C) != 0 where C is a single bit,
+ /* Otherwise we have (A & C) != 0 where C is a single bit,
convert that into ((A >> C2) & 1). Where C2 = log2(C).
Similarly for (A & C) == 0. */
inner, size_int (bitnum));
if (code == EQ_EXPR)
- inner = build2 (BIT_XOR_EXPR, intermediate_type,
- inner, integer_one_node);
+ inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
+ inner, integer_one_node));
/* Put the AND last so it can combine with more things. */
inner = build2 (BIT_AND_EXPR, intermediate_type,
return 0;
if (TREE_CONSTANT (arg0))
return 1;
-
+
if (optimize_size)
return 0;
if all operands are constant. */
int wins = 1;
- /* Don't try to process an RTL_EXPR since its operands aren't trees.
- Likewise for a SAVE_EXPR that's already been evaluated. */
- if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
- return t;
-
/* Return right away if a constant. */
if (kind == 'c')
return t;
if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
return non_lvalue (fold_convert (type, arg1));
+ /* Convert X + -C into X - C. */
+ if (TREE_CODE (arg1) == REAL_CST
+ && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
+ {
+ tem = fold_negate_const (arg1, type);
+ if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
+ return fold (build2 (MINUS_EXPR, type,
+ fold_convert (type, arg0),
+ fold_convert (type, tem)));
+ }
+
/* Convert x+x into x*2.0. */
if (operand_equal_p (arg0, arg1, 0)
&& SCALAR_FLOAT_TYPE_P (type))
tree mask0 = TREE_OPERAND (arg0, 1);
tree mask1 = TREE_OPERAND (arg1, 1);
tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
-
+
if (operand_equal_p (tem, mask1, 0))
{
tem = fold (build2 (BIT_XOR_EXPR, type,
/* A - B -> A + (-B) if B is easily negatable. */
if (!wins && negate_expr_p (arg1)
- && (FLOAT_TYPE_P (type)
+ && ((FLOAT_TYPE_P (type)
+ /* Avoid this transformation if B is a positive REAL_CST. */
+ && (TREE_CODE (arg1) != REAL_CST
+ || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
|| (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
return non_lvalue (fold_convert (type, arg0));
if (operand_equal_p (arg0, arg1, 0))
return non_lvalue (fold_convert (type, arg0));
+
+ /* ~X | X is -1. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ {
+ t1 = build_int_2 (-1, -1);
+ TREE_TYPE (t1) = type;
+ force_fit_type (t1, 0);
+ return omit_one_operand (type, t1, arg1);
+ }
+
+ /* X | ~X is -1. */
+ if (TREE_CODE (arg1) == BIT_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ {
+ t1 = build_int_2 (-1, -1);
+ TREE_TYPE (t1) = type;
+ force_fit_type (t1, 0);
+ return omit_one_operand (type, t1, arg0);
+ }
+
t1 = distribute_bit_expr (code, type, arg0, arg1);
if (t1 != NULL_TREE)
return t1;
if (operand_equal_p (arg0, arg1, 0))
return omit_one_operand (type, integer_zero_node, arg0);
+ /* ~X ^ X is -1. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ {
+ t1 = build_int_2 (-1, -1);
+ TREE_TYPE (t1) = type;
+ force_fit_type (t1, 0);
+ return omit_one_operand (type, t1, arg1);
+ }
+
+ /* X ^ ~X is -1. */
+ if (TREE_CODE (arg1) == BIT_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ {
+ t1 = build_int_2 (-1, -1);
+ TREE_TYPE (t1) = type;
+ force_fit_type (t1, 0);
+ return omit_one_operand (type, t1, arg0);
+ }
+
/* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
with a constant, and the two constants have no bits in common,
we should treat this as a BIT_IOR_EXPR since this may produce more
return omit_one_operand (type, arg1, arg0);
if (operand_equal_p (arg0, arg1, 0))
return non_lvalue (fold_convert (type, arg0));
+
+ /* ~X & X is always zero. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return omit_one_operand (type, integer_zero_node, arg1);
+
+ /* X & ~X is always zero. */
+ if (TREE_CODE (arg1) == BIT_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return omit_one_operand (type, integer_zero_node, arg0);
+
t1 = distribute_bit_expr (code, type, arg0, arg1);
if (t1 != NULL_TREE)
return t1;
return omit_one_operand (type, integer_zero_node, arg0);
if (integer_zerop (arg1))
return t;
+
/* X % -1 is zero. */
if (!TYPE_UNSIGNED (type)
&& TREE_CODE (arg1) == INTEGER_CST
&& TREE_INT_CST_HIGH (arg1) == -1)
return omit_one_operand (type, integer_zero_node, arg0);
+ /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
+ BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
+ if (code == TRUNC_MOD_EXPR
+ && TYPE_UNSIGNED (type)
+ && integer_pow2p (arg1))
+ {
+ unsigned HOST_WIDE_INT high, low;
+ tree mask;
+ int l;
+
+ l = tree_log2 (arg1);
+ if (l >= HOST_BITS_PER_WIDE_INT)
+ {
+ high = ((unsigned HOST_WIDE_INT) 1
+ << (l - HOST_BITS_PER_WIDE_INT)) - 1;
+ low = -1;
+ }
+ else
+ {
+ high = 0;
+ low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
+ }
+
+ mask = build_int_2 (low, high);
+ TREE_TYPE (mask) = type;
+ return fold (build2 (BIT_AND_EXPR, type,
+ fold_convert (type, arg0), mask));
+ }
+
+ /* X % -C is the same as X % C (for all rounding moduli). */
+ if (!TYPE_UNSIGNED (type)
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_INT_CST_HIGH (arg1) < 0
+ && !flag_trapv
+ /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
+ && !sign_bit_p (arg1, arg1))
+ return fold (build2 (code, type, fold_convert (type, arg0),
+ fold_convert (type, negate_expr (arg1))));
+
+ /* X % -Y is the same as X % Y (for all rounding moduli). */
+ if (!TYPE_UNSIGNED (type)
+ && TREE_CODE (arg1) == NEGATE_EXPR
+ && !flag_trapv)
+ return fold (build2 (code, type, fold_convert (type, arg0),
+ fold_convert (type, TREE_OPERAND (arg1, 0))));
+
if (TREE_CODE (arg1) == INTEGER_CST
&& 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
code, NULL_TREE)))
/* The argument to invert_truthvalue must have Boolean type. */
if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
arg0 = fold_convert (boolean_type_node, arg0);
-
+
/* Note that the operand of this must be an int
and its values must be 0 or 1.
("true" is a fixed value perhaps depending on the language,
if (integer_zerop (arg0))
return omit_one_operand (type, arg0, arg1);
+ /* !X && X is always false. */
+ if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return omit_one_operand (type, integer_zero_node, arg1);
+ /* X && !X is always false. */
+ if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return omit_one_operand (type, integer_zero_node, arg0);
+
truth_andor:
/* We only do these simplifications if we are optimizing. */
if (!optimize)
TRUTH_OR_EXPR. */
if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
return omit_one_operand (type, arg0, arg1);
+
+ /* !X || X is always true. */
+ if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return omit_one_operand (type, integer_one_node, arg1);
+ /* X || !X is always true. */
+ if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return omit_one_operand (type, integer_one_node, arg0);
+
goto truth_andor;
case TRUTH_XOR_EXPR:
- /* If either arg is constant zero, drop it. */
- if (integer_zerop (arg0))
- return non_lvalue (fold_convert (type, arg1));
+ /* If the second arg is constant zero, drop it. */
if (integer_zerop (arg1))
return non_lvalue (fold_convert (type, arg0));
- /* If either arg is constant true, this is a logical inversion. */
- if (integer_onep (arg0))
- return non_lvalue (fold_convert (type, invert_truthvalue (arg1)));
+ /* If the second arg is constant true, this is a logical inversion. */
if (integer_onep (arg1))
return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
/* Identical arguments cancel to zero. */
if (operand_equal_p (arg0, arg1, 0))
return omit_one_operand (type, integer_zero_node, arg0);
+
+ /* !X ^ X is always true. */
+ if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return omit_one_operand (type, integer_one_node, arg1);
+
+ /* X ^ !X is always true. */
+ if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return omit_one_operand (type, integer_one_node, arg0);
+
return t;
case EQ_EXPR:
/* If VAROP is a reference to a bitfield, we must mask
the constant by the width of the field. */
if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
- && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1)))
+ && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
+ && host_integerp (DECL_SIZE (TREE_OPERAND
+ (TREE_OPERAND (varop, 0), 1)), 1))
{
tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
- int size = TREE_INT_CST_LOW (DECL_SIZE (fielddecl));
+ HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
tree folded_compare, shift;
/* First check whether the comparison would come out
always the same. If we don't do that we would
change the meaning with the masking. */
folded_compare = fold (build2 (code, type,
- TREE_OPERAND (varop, 0),
- arg1));
+ TREE_OPERAND (varop, 0), arg1));
if (integer_zerop (folded_compare)
|| integer_onep (folded_compare))
return omit_one_operand (type, folded_compare, varop);
shift = build_int_2 (TYPE_PRECISION (TREE_TYPE (varop)) - size,
0);
+ shift = fold_convert (TREE_TYPE (varop), shift);
newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
newconst, shift));
newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
}
/* Comparisons with the highest or lowest possible integer of
- the specified size will have known values.
+ the specified size will have known values.
This is quite similar to fold_relational_hi_lo; however, my
attempts to share the code have been nothing but trouble.
&& integer_pow2p (TREE_OPERAND (arg0, 1)))
{
tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
- tree newmod = build2 (TREE_CODE (arg0), newtype,
- fold_convert (newtype,
- TREE_OPERAND (arg0, 0)),
- fold_convert (newtype,
- TREE_OPERAND (arg0, 1)));
+ tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
+ fold_convert (newtype,
+ TREE_OPERAND (arg0, 0)),
+ fold_convert (newtype,
+ TREE_OPERAND (arg0, 1))));
- return build2 (code, type, newmod, fold_convert (newtype, arg1));
+ return fold (build2 (code, type, newmod,
+ fold_convert (newtype, arg1)));
}
/* If this is an NE comparison of zero with an AND of one, remove the
t1 = fold_relational_const (code, type, arg0, arg1);
return (t1 == NULL_TREE ? t : t1);
+ case UNORDERED_EXPR:
+ case ORDERED_EXPR:
+ case UNLT_EXPR:
+ case UNLE_EXPR:
+ case UNGT_EXPR:
+ case UNGE_EXPR:
+ case UNEQ_EXPR:
+ case LTGT_EXPR:
+ if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
+ {
+ t1 = fold_relational_const (code, type, arg0, arg1);
+ if (t1 != NULL_TREE)
+ return t1;
+ }
+
+ /* If the first operand is NaN, the result is constant. */
+ if (TREE_CODE (arg0) == REAL_CST
+ && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
+ && (code != LTGT_EXPR || ! flag_trapping_math))
+ {
+ t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
+ ? integer_zero_node
+ : integer_one_node;
+ return omit_one_operand (type, t1, arg1);
+ }
+
+ /* If the second operand is NaN, the result is constant. */
+ if (TREE_CODE (arg1) == REAL_CST
+ && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
+ && (code != LTGT_EXPR || ! flag_trapping_math))
+ {
+ t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
+ ? integer_zero_node
+ : integer_one_node;
+ return omit_one_operand (type, t1, arg0);
+ }
+
+ /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
+ {
+ tree targ0 = strip_float_extensions (arg0);
+ tree targ1 = strip_float_extensions (arg1);
+ tree newtype = TREE_TYPE (targ0);
+
+ if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
+ newtype = TREE_TYPE (targ1);
+
+ if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
+ return fold (build2 (code, type, fold_convert (newtype, targ0),
+ fold_convert (newtype, targ1)));
+ }
+
+ return t;
+
case COND_EXPR:
/* Pedantic ANSI C says that a conditional expression is never an lvalue,
so all simple results must be passed through pedantic_non_lvalue. */
/* If we have A op B ? A : C, we may be able to convert this to a
simpler expression, depending on the operation and the values
of B and C. Signed zeros prevent all of these transformations,
- for reasons given above each one. */
+ for reasons given above each one.
+ Also try swapping the arguments and inverting the conditional. */
if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
&& operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
arg1, TREE_OPERAND (arg0, 1))
&& !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
{
- tree arg2 = TREE_OPERAND (t, 2);
- enum tree_code comp_code = TREE_CODE (arg0);
-
- STRIP_NOPS (arg2);
-
- /* If we have A op 0 ? A : -A, consider applying the following
- transformations:
-
- A == 0? A : -A same as -A
- A != 0? A : -A same as A
- A >= 0? A : -A same as abs (A)
- A > 0? A : -A same as abs (A)
- A <= 0? A : -A same as -abs (A)
- A < 0? A : -A same as -abs (A)
-
- None of these transformations work for modes with signed
- zeros. If A is +/-0, the first two transformations will
- change the sign of the result (from +0 to -0, or vice
- versa). The last four will fix the sign of the result,
- even though the original expressions could be positive or
- negative, depending on the sign of A.
-
- Note that all these transformations are correct if A is
- NaN, since the two alternatives (A and -A) are also NaNs. */
- if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
- ? real_zerop (TREE_OPERAND (arg0, 1))
- : integer_zerop (TREE_OPERAND (arg0, 1)))
- && TREE_CODE (arg2) == NEGATE_EXPR
- && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
- switch (comp_code)
- {
- case EQ_EXPR:
- tem = fold_convert (TREE_TYPE (TREE_OPERAND (t, 1)), arg1);
- tem = fold_convert (type, negate_expr (tem));
- return pedantic_non_lvalue (tem);
- case NE_EXPR:
- return pedantic_non_lvalue (fold_convert (type, arg1));
- case GE_EXPR:
- case GT_EXPR:
- if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
- arg1 = fold_convert (lang_hooks.types.signed_type
- (TREE_TYPE (arg1)), arg1);
- arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
- return pedantic_non_lvalue (fold_convert (type, arg1));
- case LE_EXPR:
- case LT_EXPR:
- if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
- arg1 = fold_convert (lang_hooks.types.signed_type
- (TREE_TYPE (arg1)), arg1);
- arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
- arg1 = negate_expr (fold_convert (type, arg1));
- return pedantic_non_lvalue (arg1);
- default:
- abort ();
- }
-
- /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
- A == 0 ? A : 0 is always 0 unless A is -0. Note that
- both transformations are correct when A is NaN: A != 0
- is then true, and A == 0 is false. */
-
- if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
- {
- if (comp_code == NE_EXPR)
- return pedantic_non_lvalue (fold_convert (type, arg1));
- else if (comp_code == EQ_EXPR)
- return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
- }
+ tem = fold_cond_expr_with_comparison (type, arg0,
+ TREE_OPERAND (t, 1),
+ TREE_OPERAND (t, 2));
+ if (tem)
+ return tem;
+ }
- /* Try some transformations of A op B ? A : B.
-
- A == B? A : B same as B
- A != B? A : B same as A
- A >= B? A : B same as max (A, B)
- A > B? A : B same as max (B, A)
- A <= B? A : B same as min (A, B)
- A < B? A : B same as min (B, A)
-
- As above, these transformations don't work in the presence
- of signed zeros. For example, if A and B are zeros of
- opposite sign, the first two transformations will change
- the sign of the result. In the last four, the original
- expressions give different results for (A=+0, B=-0) and
- (A=-0, B=+0), but the transformed expressions do not.
-
- The first two transformations are correct if either A or B
- is a NaN. In the first transformation, the condition will
- be false, and B will indeed be chosen. In the case of the
- second transformation, the condition A != B will be true,
- and A will be chosen.
-
- The conversions to max() and min() are not correct if B is
- a number and A is not. The conditions in the original
- expressions will be false, so all four give B. The min()
- and max() versions would give a NaN instead. */
- if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
- arg2, TREE_OPERAND (arg0, 0)))
+ if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
+ && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (t, 2),
+ TREE_OPERAND (arg0, 1))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
+ {
+ tem = invert_truthvalue (arg0);
+ if (TREE_CODE_CLASS (TREE_CODE (tem)) == '<')
{
- tree comp_op0 = TREE_OPERAND (arg0, 0);
- tree comp_op1 = TREE_OPERAND (arg0, 1);
- tree comp_type = TREE_TYPE (comp_op0);
-
- /* Avoid adding NOP_EXPRs in case this is an lvalue. */
- if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
- {
- comp_type = type;
- comp_op0 = arg1;
- comp_op1 = arg2;
- }
-
- switch (comp_code)
- {
- case EQ_EXPR:
- return pedantic_non_lvalue (fold_convert (type, arg2));
- case NE_EXPR:
- return pedantic_non_lvalue (fold_convert (type, arg1));
- case LE_EXPR:
- case LT_EXPR:
- /* In C++ a ?: expression can be an lvalue, so put the
- operand which will be used if they are equal first
- so that we can convert this back to the
- corresponding COND_EXPR. */
- if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
- return pedantic_non_lvalue (fold_convert
- (type, fold (build2 (MIN_EXPR, comp_type,
- (comp_code == LE_EXPR
- ? comp_op0 : comp_op1),
- (comp_code == LE_EXPR
- ? comp_op1 : comp_op0)))));
- break;
- case GE_EXPR:
- case GT_EXPR:
- if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
- return pedantic_non_lvalue (fold_convert
- (type, fold (build2 (MAX_EXPR, comp_type,
- (comp_code == GE_EXPR
- ? comp_op0 : comp_op1),
- (comp_code == GE_EXPR
- ? comp_op1 : comp_op0)))));
- break;
- default:
- abort ();
- }
+ tem = fold_cond_expr_with_comparison (type, tem,
+ TREE_OPERAND (t, 2),
+ TREE_OPERAND (t, 1));
+ if (tem)
+ return tem;
}
-
- /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
- we might still be able to simplify this. For example,
- if C1 is one less or one more than C2, this might have started
- out as a MIN or MAX and been transformed by this function.
- Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
-
- if (INTEGRAL_TYPE_P (type)
- && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
- && TREE_CODE (arg2) == INTEGER_CST)
- switch (comp_code)
- {
- case EQ_EXPR:
- /* We can replace A with C1 in this case. */
- arg1 = fold_convert (type, TREE_OPERAND (arg0, 1));
- return fold (build3 (code, type, TREE_OPERAND (t, 0), arg1,
- TREE_OPERAND (t, 2)));
-
- case LT_EXPR:
- /* If C1 is C2 + 1, this is min(A, C2). */
- if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
- OEP_ONLY_CONST)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- const_binop (PLUS_EXPR, arg2,
- integer_one_node, 0),
- OEP_ONLY_CONST))
- return pedantic_non_lvalue
- (fold (build2 (MIN_EXPR, type, arg1, arg2)));
- break;
-
- case LE_EXPR:
- /* If C1 is C2 - 1, this is min(A, C2). */
- if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
- OEP_ONLY_CONST)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- const_binop (MINUS_EXPR, arg2,
- integer_one_node, 0),
- OEP_ONLY_CONST))
- return pedantic_non_lvalue
- (fold (build2 (MIN_EXPR, type, arg1, arg2)));
- break;
-
- case GT_EXPR:
- /* If C1 is C2 - 1, this is max(A, C2). */
- if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
- OEP_ONLY_CONST)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- const_binop (MINUS_EXPR, arg2,
- integer_one_node, 0),
- OEP_ONLY_CONST))
- return pedantic_non_lvalue
- (fold (build2 (MAX_EXPR, type, arg1, arg2)));
- break;
-
- case GE_EXPR:
- /* If C1 is C2 + 1, this is max(A, C2). */
- if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
- OEP_ONLY_CONST)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- const_binop (PLUS_EXPR, arg2,
- integer_one_node, 0),
- OEP_ONLY_CONST))
- return pedantic_non_lvalue
- (fold (build2 (MAX_EXPR, type, arg1, arg2)));
- break;
- case NE_EXPR:
- break;
- default:
- abort ();
- }
}
/* If the second operand is simpler than the third, swap them
return pedantic_non_lvalue (fold_convert (type,
invert_truthvalue (arg0)));
- /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
- operation is simply A & 2. */
+ /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
+ if (TREE_CODE (arg0) == LT_EXPR
+ && integer_zerop (TREE_OPERAND (arg0, 1))
+ && integer_zerop (TREE_OPERAND (t, 2))
+ && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
+ return fold_convert (type, fold (build2 (BIT_AND_EXPR,
+ TREE_TYPE (tem), tem, arg1)));
+
+ /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
+ already handled above. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && integer_onep (TREE_OPERAND (arg0, 1))
+ && integer_zerop (TREE_OPERAND (t, 2))
+ && integer_pow2p (arg1))
+ {
+ tree tem = TREE_OPERAND (arg0, 0);
+ STRIP_NOPS (tem);
+ if (TREE_CODE (tem) == RSHIFT_EXPR
+ && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
+ TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
+ return fold (build2 (BIT_AND_EXPR, type,
+ TREE_OPERAND (tem, 0), arg1));
+ }
+ /* A & N ? N : 0 is simply A & N if N is a power of two. This
+ is probably obsolete because the first operand should be a
+ truth value (that's why we have the two cases above), but let's
+ leave it in until we can confirm this for all front-ends. */
if (integer_zerop (TREE_OPERAND (t, 2))
&& TREE_CODE (arg0) == NE_EXPR
&& integer_zerop (TREE_OPERAND (arg0, 1))
if (integer_zerop (TREE_OPERAND (t, 2))
&& truth_value_p (TREE_CODE (arg0))
&& truth_value_p (TREE_CODE (arg1)))
- return pedantic_non_lvalue (fold (build2 (TRUTH_ANDIF_EXPR, type,
- arg0, arg1)));
+ return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
/* Convert A ? B : 1 into !A || B if A and B are truth values. */
if (integer_onep (TREE_OPERAND (t, 2))
/* Only perform transformation if ARG0 is easily inverted. */
tem = invert_truthvalue (arg0);
if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
- return pedantic_non_lvalue (fold (build2 (TRUTH_ORIF_EXPR, type,
- tem, arg1)));
+ return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
}
+ /* Convert A ? 0 : B into !A && B if A and B are truth values. */
+ if (integer_zerop (arg1)
+ && truth_value_p (TREE_CODE (arg0))
+ && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
+ {
+ /* Only perform transformation if ARG0 is easily inverted. */
+ tem = invert_truthvalue (arg0);
+ if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
+ return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
+ TREE_OPERAND (t, 2)));
+ }
+
+ /* Convert A ? 1 : B into A || B if A and B are truth values. */
+ if (integer_onep (arg1)
+ && truth_value_p (TREE_CODE (arg0))
+ && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
+ return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
+ TREE_OPERAND (t, 2)));
+
return t;
case COMPOUND_EXPR:
== FUNCTION_DECL)
&& DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
{
- tree tmp = fold_builtin (t);
+ tree tmp = fold_builtin (t, false);
if (tmp)
return tmp;
}
return;
*slot = expr;
code = TREE_CODE (expr);
- if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
- {
- /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
- memcpy (buf, expr, tree_size (expr));
- expr = (tree) buf;
- SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
- }
- else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
+ if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
{
/* Allow DECL_ASSEMBLER_NAME to be modified. */
memcpy (buf, expr, tree_size (expr));
fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
- len = TREE_CODE_LENGTH (code);
switch (TREE_CODE_CLASS (code))
{
case 'c':
}
break;
case 'e':
- switch (code)
- {
- case SAVE_EXPR: len = 2; break;
- case GOTO_SUBROUTINE_EXPR: len = 0; break;
- case RTL_EXPR: len = 0; break;
- case WITH_CLEANUP_EXPR: len = 2; break;
- default: break;
- }
- /* Fall through. */
case 'r':
case '<':
case '1':
case '2':
case 's':
+ len = first_rtl_op (code);
for (i = 0; i < len; ++i)
fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
break;
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
case FLOAT_EXPR:
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
- case RTL_EXPR:
- return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
+
+ case TARGET_EXPR:
+ {
+ tree temp = TARGET_EXPR_SLOT (t);
+ t = TARGET_EXPR_INITIAL (t);
+
+ /* If the initializer is non-void, then it's a normal expression
+ that will be assigned to the slot. */
+ if (!VOID_TYPE_P (t))
+ return tree_expr_nonnegative_p (t);
+
+ /* Otherwise, the initializer sets the slot in some way. One common
+ way is an assignment statement at the end of the initializer. */
+ while (1)
+ {
+ if (TREE_CODE (t) == BIND_EXPR)
+ t = expr_last (BIND_EXPR_BODY (t));
+ else if (TREE_CODE (t) == TRY_FINALLY_EXPR
+ || TREE_CODE (t) == TRY_CATCH_EXPR)
+ t = expr_last (TREE_OPERAND (t, 0));
+ else if (TREE_CODE (t) == STATEMENT_LIST)
+ t = expr_last (t);
+ else
+ break;
+ }
+ if (TREE_CODE (t) == MODIFY_EXPR
+ && TREE_OPERAND (t, 0) == temp)
+ return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
+
+ return 0;
+ }
case CALL_EXPR:
{
return tem;
}
return NULL_TREE;
-
+
case MINUS_EXPR:
/* Fold &x - &x. This can happen from &x.foo - &x.
This is unsafe for certain floats even in non-IEEE formats.
return omit_one_operand (type, op1, op0);
goto binary;
-
+
case TRUNC_DIV_EXPR:
case ROUND_DIV_EXPR:
case FLOOR_DIV_EXPR:
if (tem)
return tem;
+ /* Fall through. */
+
+ case ORDERED_EXPR:
+ case UNORDERED_EXPR:
+ case UNLT_EXPR:
+ case UNLE_EXPR:
+ case UNGT_EXPR:
+ case UNGE_EXPR:
+ case UNEQ_EXPR:
+ case LTGT_EXPR:
if (!wins)
return NULL_TREE;
/* Given the components of a unary expression CODE, TYPE and OP0,
attempt to fold the expression to a constant without modifying
- TYPE or OP0.
+ TYPE or OP0.
If the expression could be simplified to a constant, then return
the constant. If the expression would not be simplified to a
tree string;
if (TREE_CODE (exp) == INDIRECT_REF)
- {
- string = string_constant (exp1, &index);
- }
+ string = string_constant (exp1, &index);
else
{
- tree domain = TYPE_DOMAIN (TREE_TYPE (exp1));
- tree low_bound = domain ? TYPE_MIN_VALUE (domain) : integer_zero_node;
+ tree low_bound = array_ref_low_bound (exp);
index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
-
+
/* Optimize the special-case of a zero lower bound.
We convert the low_bound to sizetype to avoid some problems
}
if (string
+ && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
&& TREE_CODE (string) == STRING_CST
&& TREE_CODE (index) == INTEGER_CST
&& compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
else
abort ();
#endif
-
+
return t;
}
else
abort ();
#endif
-
+
return t;
}
else
abort ();
#endif
-
+
return t;
}
int result, invert;
/* From here on, the only cases we handle are when the result is
- known to be a constant.
+ known to be a constant. */
+
+ if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
+ {
+ /* Handle the cases where either operand is a NaN. */
+ if (REAL_VALUE_ISNAN (TREE_REAL_CST (op0))
+ || REAL_VALUE_ISNAN (TREE_REAL_CST (op1)))
+ {
+ switch (code)
+ {
+ case EQ_EXPR:
+ case ORDERED_EXPR:
+ result = 0;
+ break;
+
+ case NE_EXPR:
+ case UNORDERED_EXPR:
+ case UNLT_EXPR:
+ case UNLE_EXPR:
+ case UNGT_EXPR:
+ case UNGE_EXPR:
+ case UNEQ_EXPR:
+ result = 1;
+ break;
+
+ case LT_EXPR:
+ case LE_EXPR:
+ case GT_EXPR:
+ case GE_EXPR:
+ case LTGT_EXPR:
+ if (flag_trapping_math)
+ return NULL_TREE;
+ result = 0;
+ break;
+
+ default:
+ abort ();
+ }
+
+ return constant_boolean_node (result, type);
+ }
+
+ /* From here on we're sure there are no NaNs. */
+ switch (code)
+ {
+ case ORDERED_EXPR:
+ return constant_boolean_node (true, type);
+
+ case UNORDERED_EXPR:
+ return constant_boolean_node (false, type);
+
+ case UNLT_EXPR:
+ code = LT_EXPR;
+ break;
+ case UNLE_EXPR:
+ code = LE_EXPR;
+ break;
+ case UNGT_EXPR:
+ code = GT_EXPR;
+ break;
+ case UNGE_EXPR:
+ code = GE_EXPR;
+ break;
+ case UNEQ_EXPR:
+ code = EQ_EXPR;
+ break;
+ case LTGT_EXPR:
+ code = NE_EXPR;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ /* From here on we only handle LT, LE, GT, GE, EQ and NE.
To compute GT, swap the arguments and do LT.
To compute GE, do LT and invert the result.
}
/* Note that it is safe to invert for real values here because we
- will check below in the one case that it matters. */
+ have already handled the one case that it matters. */
invert = 0;
if (code == NE_EXPR || code == GE_EXPR)
/* Two real constants can be compared explicitly. */
else if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
{
- /* If either operand is a NaN, the result is false with two
- exceptions: First, an NE_EXPR is true on NaNs, but that case
- is already handled correctly since we will be inverting the
- result for NE_EXPR. Second, if we had inverted a LE_EXPR
- or a GE_EXPR into a LT_EXPR, we must return true so that it
- will be inverted into false. */
-
- if (REAL_VALUE_ISNAN (TREE_REAL_CST (op0))
- || REAL_VALUE_ISNAN (TREE_REAL_CST (op1)))
- result = invert && code == LT_EXPR;
-
- else if (code == EQ_EXPR)
+ if (code == EQ_EXPR)
result = REAL_VALUES_EQUAL (TREE_REAL_CST (op0),
TREE_REAL_CST (op1));
else
else
{
tree base = t;
- while (TREE_CODE (base) == COMPONENT_REF
- || TREE_CODE (base) == ARRAY_REF)
+
+ while (handled_component_p (base)
+ || TREE_CODE (base) == REALPART_EXPR
+ || TREE_CODE (base) == IMAGPART_EXPR)
base = TREE_OPERAND (base, 0);
if (DECL_P (base))
TREE_ADDRESSABLE (base) = 1;
/* *(foo *)&fooarray => fooarray[0] */
else if (TREE_CODE (optype) == ARRAY_TYPE
&& lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
- return build2 (ARRAY_REF, type, op, size_zero_node);
+ return build4 (ARRAY_REF, type, op, size_zero_node, NULL_TREE, NULL_TREE);
}
/* *(foo *)fooarrptr => (*fooarrptr)[0] */
&& lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
{
sub = build_fold_indirect_ref (sub);
- return build2 (ARRAY_REF, type, sub, size_zero_node);
+ return build4 (ARRAY_REF, type, sub, size_zero_node, NULL_TREE, NULL_TREE);
}
return build1 (INDIRECT_REF, type, t);
}
+/* Strip non-trapping, non-side-effecting tree nodes from an expression
+ whose result is ignored. The type of the returned tree need not be
+ the same as the original expression. */
+
+tree
+fold_ignored_result (tree t)
+{
+ if (!TREE_SIDE_EFFECTS (t))
+ return integer_zero_node;
+
+ for (;;)
+ switch (TREE_CODE_CLASS (TREE_CODE (t)))
+ {
+ case '1':
+ t = TREE_OPERAND (t, 0);
+ break;
+
+ case '2':
+ case '<':
+ if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
+ t = TREE_OPERAND (t, 0);
+ else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
+ t = TREE_OPERAND (t, 1);
+ else
+ return t;
+ break;
+
+ case 'e':
+ switch (TREE_CODE (t))
+ {
+ case COMPOUND_EXPR:
+ if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
+ return t;
+ t = TREE_OPERAND (t, 0);
+ break;
+
+ case COND_EXPR:
+ if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
+ || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
+ return t;
+ t = TREE_OPERAND (t, 0);
+ break;
+
+ default:
+ return t;
+ }
+ break;
+
+ default:
+ return t;
+ }
+}
+
#include "gt-fold-const.h"
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