From: Rafael Avila de Espindola Date: Tue, 4 Mar 2008 22:20:34 +0000 (+0000) Subject: fold-const.c (tree_simple_nonnegative_warnv_p): New. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=e918a58a835bf5e8c36ffff29d619fa778c2a347;p=gcc.git fold-const.c (tree_simple_nonnegative_warnv_p): New. 2008-03-04 Rafael Espindola * 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 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index f0425f8b219..a536011f817 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2008-03-04 Rafael Espindola + + * 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 PR 28322 diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 503da6a7d49..e32a737f292 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -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. */ - 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. */