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fold-const.c (tree_simple_nonnegative_warnv_p): New.

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2008-03-04  Rafael Espindola  <espindola@google.com>

        * fold-const.c (tree_simple_nonnegative_warnv_p): New.
        (tree_unary_nonnegative_warnv_p): New.
        (tree_binary_nonnegative_warnv_p): New.
        (tree_single_nonnegative_warnv_p): New.
        (tree_invalid_nonnegative_warnv_p): New.
        (tree_expr_nonnegative_warnv_p): Redefine in term of the new functions.

From-SVN: r132875
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Rafael Avila de Espindola 2008-03-04 22:20:34 +00:00 committed by Rafael Espindola
parent 2925e1c8ad
commit e918a58a83
2 changed files with 247 additions and 94 deletions
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9
gcc/ChangeLog
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@ -1,3 +1,12 @@
2008-03-04 Rafael Espindola <espindola@google.com>
* fold-const.c (tree_simple_nonnegative_warnv_p): New.
(tree_unary_nonnegative_warnv_p): New.
(tree_binary_nonnegative_warnv_p): New.
(tree_single_nonnegative_warnv_p): New.
(tree_invalid_nonnegative_warnv_p): New.
(tree_expr_nonnegative_warnv_p): Redefine in term of the new functions.
2008-03-04 Manuel Lopez-Ibanez <manu@gcc.gnu.org>
PR 28322

332
gcc/fold-const.c
View File

@ -14043,106 +14043,161 @@ multiple_of_p (tree type, const_tree top, const_tree bottom)
}
}
/* Return true if `t' is known to be non-negative. If the return
/* Return true if CODE or TYPE is known to be non-negative. */
static bool
tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
{
if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
&& truth_value_p (code))
/* Truth values evaluate to 0 or 1, which is nonnegative unless we
have a signed:1 type (where the value is -1 and 0). */
return true;
return false;
}
/* Return true if (CODE OP0) is known to be non-negative. If the return
value is based on the assumption that signed overflow is undefined,
set *STRICT_OVERFLOW_P to true; otherwise, don't change
*STRICT_OVERFLOW_P. */
bool
tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
static bool
tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
bool *strict_overflow_p)
{
if (t == error_mark_node)
return false;
if (TYPE_UNSIGNED (TREE_TYPE (t)))
if (TYPE_UNSIGNED (type))
return true;
switch (TREE_CODE (t))
switch (code)
{
case SSA_NAME:
/* Query VRP to see if it has recorded any information about
the range of this object. */
return ssa_name_nonnegative_p (t);
case ABS_EXPR:
/* We can't return 1 if flag_wrapv is set because
ABS_EXPR<INT_MIN> = INT_MIN. */
if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
if (!INTEGRAL_TYPE_P (type))
return true;
if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
if (TYPE_OVERFLOW_UNDEFINED (type))
{
*strict_overflow_p = true;
return true;
}
break;
case INTEGER_CST:
return tree_int_cst_sgn (t) >= 0;
case NON_LVALUE_EXPR:
case FLOAT_EXPR:
case FIX_TRUNC_EXPR:
return tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p);
case REAL_CST:
return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
case NOP_EXPR:
{
tree inner_type = TREE_TYPE (op0);
tree outer_type = type;
case FIXED_CST:
return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
if (TREE_CODE (outer_type) == REAL_TYPE)
{
if (TREE_CODE (inner_type) == REAL_TYPE)
return tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p);
if (TREE_CODE (inner_type) == INTEGER_TYPE)
{
if (TYPE_UNSIGNED (inner_type))
return true;
return tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p);
}
}
else if (TREE_CODE (outer_type) == INTEGER_TYPE)
{
if (TREE_CODE (inner_type) == REAL_TYPE)
return tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p);
if (TREE_CODE (inner_type) == INTEGER_TYPE)
return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
&& TYPE_UNSIGNED (inner_type);
}
}
break;
default:
return tree_simple_nonnegative_warnv_p (code, type);
}
/* We don't know sign of `t', so be conservative and return false. */
return false;
}
/* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
value is based on the assumption that signed overflow is undefined,
set *STRICT_OVERFLOW_P to true; otherwise, don't change
*STRICT_OVERFLOW_P. */
static bool
tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
tree op1, bool *strict_overflow_p)
{
if (TYPE_UNSIGNED (type))
return true;
switch (code)
{
case POINTER_PLUS_EXPR:
case PLUS_EXPR:
if (FLOAT_TYPE_P (TREE_TYPE (t)))
return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
if (FLOAT_TYPE_P (type))
return (tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p)
&& tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
&& tree_expr_nonnegative_warnv_p (op1,
strict_overflow_p));
/* zero_extend(x) + zero_extend(y) is non-negative if x and y are
both unsigned and at least 2 bits shorter than the result. */
if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
&& TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
&& TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
if (TREE_CODE (type) == INTEGER_TYPE
&& TREE_CODE (op0) == NOP_EXPR
&& TREE_CODE (op1) == NOP_EXPR)
{
tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
&& TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
{
unsigned int prec = MAX (TYPE_PRECISION (inner1),
TYPE_PRECISION (inner2)) + 1;
return prec < TYPE_PRECISION (TREE_TYPE (t));
return prec < TYPE_PRECISION (type);
}
}
break;
case MULT_EXPR:
if (FLOAT_TYPE_P (TREE_TYPE (t)))
if (FLOAT_TYPE_P (type))
{
/* x * x for floating point x is always non-negative. */
if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
if (operand_equal_p (op0, op1, 0))
return true;
return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
return (tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p)
&& tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
&& tree_expr_nonnegative_warnv_p (op1,
strict_overflow_p));
}
/* zero_extend(x) * zero_extend(y) is non-negative if x and y are
both unsigned and their total bits is shorter than the result. */
if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
&& TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
&& TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
if (TREE_CODE (type) == INTEGER_TYPE
&& TREE_CODE (op0) == NOP_EXPR
&& TREE_CODE (op1) == NOP_EXPR)
{
tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
&& TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
< TYPE_PRECISION (TREE_TYPE (t));
< TYPE_PRECISION (type);
}
return false;
case BIT_AND_EXPR:
case MAX_EXPR:
return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
return (tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p)
|| tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
|| tree_expr_nonnegative_warnv_p (op1,
strict_overflow_p));
case BIT_IOR_EXPR:
@ -14153,68 +14208,80 @@ tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
case CEIL_DIV_EXPR:
case FLOOR_DIV_EXPR:
case ROUND_DIV_EXPR:
return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
return (tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p)
&& tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
&& tree_expr_nonnegative_warnv_p (op1,
strict_overflow_p));
case TRUNC_MOD_EXPR:
case CEIL_MOD_EXPR:
case FLOOR_MOD_EXPR:
case ROUND_MOD_EXPR:
case SAVE_EXPR:
case NON_LVALUE_EXPR:
case FLOAT_EXPR:
case FIX_TRUNC_EXPR:
return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
return tree_expr_nonnegative_warnv_p (op0,
strict_overflow_p);
default:
return tree_simple_nonnegative_warnv_p (code, type);
}
case COMPOUND_EXPR:
case MODIFY_EXPR:
case GIMPLE_MODIFY_STMT:
return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
strict_overflow_p);
/* We don't know sign of `t', so be conservative and return false. */
return false;
}
case BIND_EXPR:
return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
strict_overflow_p);
/* Return true if T is known to be non-negative. If the return
value is based on the assumption that signed overflow is undefined,
set *STRICT_OVERFLOW_P to true; otherwise, don't change
*STRICT_OVERFLOW_P. */
static bool
tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
{
if (TYPE_UNSIGNED (TREE_TYPE (t)))
return true;
enum tree_code code = TREE_CODE (t);
switch (code)
{
case SSA_NAME:
/* Query VRP to see if it has recorded any information about
the range of this object. */
return ssa_name_nonnegative_p (t);
case INTEGER_CST:
return tree_int_cst_sgn (t) >= 0;
case REAL_CST:
return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
case FIXED_CST:
return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
case COND_EXPR:
return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
strict_overflow_p)
&& tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
strict_overflow_p));
default:
return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
TREE_TYPE (t));
}
/* We don't know sign of `t', so be conservative and return false. */
return false;
}
case NOP_EXPR:
{
tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
tree outer_type = TREE_TYPE (t);
/* Return true if T is known to be non-negative. If the return
value is based on the assumption that signed overflow is undefined,
set *STRICT_OVERFLOW_P to true; otherwise, don't change
*STRICT_OVERFLOW_P. */
if (TREE_CODE (outer_type) == REAL_TYPE)
{
if (TREE_CODE (inner_type) == REAL_TYPE)
return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
strict_overflow_p);
if (TREE_CODE (inner_type) == INTEGER_TYPE)
{
if (TYPE_UNSIGNED (inner_type))
return true;
return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
strict_overflow_p);
}
}
else if (TREE_CODE (outer_type) == INTEGER_TYPE)
{
if (TREE_CODE (inner_type) == REAL_TYPE)
return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
strict_overflow_p);
if (TREE_CODE (inner_type) == INTEGER_TYPE)
return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
&& TYPE_UNSIGNED (inner_type);
}
}
break;
static bool
tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
{
if (TYPE_UNSIGNED (TREE_TYPE (t)))
return true;
enum tree_code code = TREE_CODE (t);
switch (code)
{
case TARGET_EXPR:
{
tree temp = TARGET_EXPR_SLOT (t);
@ -14372,25 +14439,102 @@ tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
default:
break;
}
return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
TREE_TYPE (t));
}
break;
/* ... fall through ... */
case COMPOUND_EXPR:
case MODIFY_EXPR:
case GIMPLE_MODIFY_STMT:
return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
strict_overflow_p);
case BIND_EXPR:
return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
strict_overflow_p);
case SAVE_EXPR:
return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
strict_overflow_p);
default:
{
tree type = TREE_TYPE (t);
if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
&& truth_value_p (TREE_CODE (t)))
/* Truth values evaluate to 0 or 1, which is nonnegative unless we
have a signed:1 type (where the value is -1 and 0). */
return true;
}
return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
TREE_TYPE (t));
}
/* We don't know sign of `t', so be conservative and return false. */
return false;
}
/* Return true if T is known to be non-negative. If the return
value is based on the assumption that signed overflow is undefined,
set *STRICT_OVERFLOW_P to true; otherwise, don't change
*STRICT_OVERFLOW_P. */
bool
tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
{
enum tree_code code;
if (t == error_mark_node)
return false;
code = TREE_CODE (t);
switch (TREE_CODE_CLASS (code))
{
case tcc_binary:
case tcc_comparison:
return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
TREE_TYPE (t),
TREE_OPERAND (t, 0),
TREE_OPERAND (t, 1),
strict_overflow_p);
case tcc_unary:
return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
TREE_TYPE (t),
TREE_OPERAND (t, 0),
strict_overflow_p);
case tcc_constant:
case tcc_declaration:
case tcc_reference:
return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
default:
break;
}
switch (code)
{
case TRUTH_AND_EXPR:
case TRUTH_OR_EXPR:
case TRUTH_XOR_EXPR:
return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
TREE_TYPE (t),
TREE_OPERAND (t, 0),
TREE_OPERAND (t, 1),
strict_overflow_p);
case TRUTH_NOT_EXPR:
return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
TREE_TYPE (t),
TREE_OPERAND (t, 0),
strict_overflow_p);
case COND_EXPR:
case CONSTRUCTOR:
case OBJ_TYPE_REF:
case ASSERT_EXPR:
case ADDR_EXPR:
case WITH_SIZE_EXPR:
case EXC_PTR_EXPR:
case SSA_NAME:
case FILTER_EXPR:
return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
default:
return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
}
}
/* Return true if `t' is known to be non-negative. Handle warnings
about undefined signed overflow. */