X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fc-convert.c;h=947c79bcadb3e9ce891a8715b30b1ecec481028e;hb=aae061fde2843546ed8ff13a4e58cec9d0f5f47d;hp=89637cb7364c763f60023169fc2cd46a8b6dd0bb;hpb=ad59b569036d9ac5496c2b82ec9f233bdd8d6322;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/c-convert.c b/gcc/c-convert.c index 89637cb7364..947c79bcadb 100644 --- a/gcc/c-convert.c +++ b/gcc/c-convert.c @@ -1,21 +1,22 @@ /* Language-level data type conversion for GNU C. - Copyright (C) 1987, 1988, 1991 Free Software Foundation, Inc. + Copyright (C) 1987, 1988, 1991, 1998 Free Software Foundation, Inc. -This file is part of GNU CC. +This file is part of GCC. -GNU CC 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 later version. +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 later +version. -GNU CC is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. You should have received a copy of the GNU General Public License -along with GNU CC; see the file COPYING. If not, write to -the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ +along with GCC; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA +02111-1307, USA. */ /* This file contains the functions for converting C expressions @@ -24,8 +25,11 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ but what kind of conversions it does will depend on the language. */ #include "config.h" +#include "system.h" #include "tree.h" #include "flags.h" +#include "convert.h" +#include "toplev.h" /* Change of width--truncation and extension of integers or reals-- is represented with NOP_EXPR. Proper functioning of many things @@ -37,7 +41,7 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ Here is a list of all the functions that assume that widening and narrowing is always done with a NOP_EXPR: - In c-convert.c, convert_to_integer. + In convert.c, convert_to_integer. In c-typeck.c, build_binary_op (boolean ops), and truthvalue_conversion. In expr.c: expand_expr, for operands of a MULT_EXPR. In fold-const.c: fold. @@ -45,330 +49,7 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Subroutines of `convert'. */ -static tree -convert_to_pointer (type, expr) - tree type, expr; -{ - register tree intype = TREE_TYPE (expr); - register enum tree_code form = TREE_CODE (intype); - - if (integer_zerop (expr)) - { - if (type == TREE_TYPE (null_pointer_node)) - return null_pointer_node; - expr = build_int_2 (0, 0); - TREE_TYPE (expr) = type; - return expr; - } - - if (form == POINTER_TYPE) - return build1 (NOP_EXPR, type, expr); - - - if (form == INTEGER_TYPE || form == ENUMERAL_TYPE) - { - if (type_precision (intype) == POINTER_SIZE) - return build1 (CONVERT_EXPR, type, expr); - expr = convert (type_for_size (POINTER_SIZE, 0), expr); - if (TYPE_MODE (TREE_TYPE (expr)) != TYPE_MODE (type)) - /* There is supposed to be some integral type - that is the same width as a pointer. */ - abort (); - return convert_to_pointer (type, expr); - } - - error ("cannot convert to a pointer type"); - - return null_pointer_node; -} - -static tree -convert_to_real (type, expr) - tree type, expr; -{ - register enum tree_code form = TREE_CODE (TREE_TYPE (expr)); - if (form == REAL_TYPE) - return build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR, - type, expr); - - if (form == INTEGER_TYPE || form == ENUMERAL_TYPE) - return build1 (FLOAT_EXPR, type, expr); - - if (form == POINTER_TYPE) - error ("pointer value used where a float was expected"); - else - error ("aggregate value used where a float was expected"); - - { - register tree tem = make_node (REAL_CST); - TREE_TYPE (tem) = type; - TREE_REAL_CST (tem) = REAL_VALUE_ATOF ("0.0"); - return tem; - } -} - -/* The result of this is always supposed to be a newly created tree node - not in use in any existing structure. */ - -static tree -convert_to_integer (type, expr) - tree type, expr; -{ - register tree intype = TREE_TYPE (expr); - register enum tree_code form = TREE_CODE (intype); - - if (form == POINTER_TYPE) - { - if (integer_zerop (expr)) - expr = integer_zero_node; - else - expr = fold (build1 (CONVERT_EXPR, - type_for_size (POINTER_SIZE, 0), expr)); - intype = TREE_TYPE (expr); - form = TREE_CODE (intype); - if (intype == type) - return expr; - } - - if (form == INTEGER_TYPE || form == ENUMERAL_TYPE) - { - register unsigned outprec = TYPE_PRECISION (type); - register unsigned inprec = TYPE_PRECISION (intype); - register enum tree_code ex_form = TREE_CODE (expr); - - /* If we are widening the type, put in an explicit conversion. - Similarly if we are not changing the width. However, if this is - a logical operation that just returns 0 or 1, we can change the - type of the expression (see below). */ - - if (TREE_CODE_CLASS (ex_form) == '<' - || ex_form == TRUTH_AND_EXPR || ex_form == TRUTH_ANDIF_EXPR - || ex_form == TRUTH_OR_EXPR || ex_form == TRUTH_ORIF_EXPR - || ex_form == TRUTH_NOT_EXPR) - { - TREE_TYPE (expr) = type; - return expr; - } - else if (outprec >= inprec) - return build1 (NOP_EXPR, type, expr); - -/* Here detect when we can distribute the truncation down past some arithmetic. - For example, if adding two longs and converting to an int, - we can equally well convert both to ints and then add. - For the operations handled here, such truncation distribution - is always safe. - It is desirable in these cases: - 1) when truncating down to full-word from a larger size - 2) when truncating takes no work. - 3) when at least one operand of the arithmetic has been extended - (as by C's default conversions). In this case we need two conversions - if we do the arithmetic as already requested, so we might as well - truncate both and then combine. Perhaps that way we need only one. - - Note that in general we cannot do the arithmetic in a type - shorter than the desired result of conversion, even if the operands - are both extended from a shorter type, because they might overflow - if combined in that type. The exceptions to this--the times when - two narrow values can be combined in their narrow type even to - make a wider result--are handled by "shorten" in build_binary_op. */ - - switch (ex_form) - { - case RSHIFT_EXPR: - /* We can pass truncation down through right shifting - when the shift count is a nonpositive constant. */ - if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST - && tree_int_cst_lt (TREE_OPERAND (expr, 1), integer_one_node)) - goto trunc1; - break; - - case LSHIFT_EXPR: - /* We can pass truncation down through left shifting - when the shift count is a nonnegative constant. */ - if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST - && ! tree_int_cst_lt (TREE_OPERAND (expr, 1), integer_zero_node) - && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST) - { - /* If shift count is less than the width of the truncated type, - really shift. */ - if (tree_int_cst_lt (TREE_OPERAND (expr, 1), TYPE_SIZE (type))) - /* In this case, shifting is like multiplication. */ - goto trunc1; - else - /* If it is >= that width, result is zero. - Handling this with trunc1 would give the wrong result: - (int) ((long long) a << 32) is well defined (as 0) - but (int) a << 32 is undefined and would get a warning. */ - return convert_to_integer (type, integer_zero_node); - } - break; - - case MAX_EXPR: - case MIN_EXPR: - case MULT_EXPR: - { - tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type); - tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type); - - /* Don't distribute unless the output precision is at least as big - as the actual inputs. Otherwise, the comparison of the - truncated values will be wrong. */ - if (outprec >= TYPE_PRECISION (TREE_TYPE (arg0)) - && outprec >= TYPE_PRECISION (TREE_TYPE (arg1)) - /* If signedness of arg0 and arg1 don't match, - we can't necessarily find a type to compare them in. */ - && (TREE_UNSIGNED (TREE_TYPE (arg0)) - == TREE_UNSIGNED (TREE_TYPE (arg1)))) - goto trunc1; - break; - } - - case PLUS_EXPR: - case MINUS_EXPR: - case BIT_AND_EXPR: - case BIT_IOR_EXPR: - case BIT_XOR_EXPR: - case BIT_ANDTC_EXPR: - trunc1: - { - tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type); - tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type); - - if (outprec >= BITS_PER_WORD - || TRULY_NOOP_TRUNCATION (outprec, inprec) - || inprec > TYPE_PRECISION (TREE_TYPE (arg0)) - || inprec > TYPE_PRECISION (TREE_TYPE (arg1))) - { - /* Do the arithmetic in type TYPEX, - then convert result to TYPE. */ - register tree typex = type; - - /* Can't do arithmetic in enumeral types - so use an integer type that will hold the values. */ - if (TREE_CODE (typex) == ENUMERAL_TYPE) - typex = type_for_size (TYPE_PRECISION (typex), - TREE_UNSIGNED (typex)); - - /* But now perhaps TYPEX is as wide as INPREC. - In that case, do nothing special here. - (Otherwise would recurse infinitely in convert. */ - if (TYPE_PRECISION (typex) != inprec) - { - /* Don't do unsigned arithmetic where signed was wanted, - or vice versa. - Exception: if either of the original operands were - unsigned then can safely do the work as unsigned. - And we may need to do it as unsigned - if we truncate to the original size. */ - typex = ((TREE_UNSIGNED (TREE_TYPE (expr)) - || TREE_UNSIGNED (TREE_TYPE (arg0)) - || TREE_UNSIGNED (TREE_TYPE (arg1))) - ? unsigned_type (typex) : signed_type (typex)); - return convert (type, - build_binary_op (ex_form, - convert (typex, arg0), - convert (typex, arg1), - 0)); - } - } - } - break; - - case NEGATE_EXPR: - case BIT_NOT_EXPR: - { - register tree typex = type; - - /* Can't do arithmetic in enumeral types - so use an integer type that will hold the values. */ - if (TREE_CODE (typex) == ENUMERAL_TYPE) - typex = type_for_size (TYPE_PRECISION (typex), - TREE_UNSIGNED (typex)); - - /* But now perhaps TYPEX is as wide as INPREC. - In that case, do nothing special here. - (Otherwise would recurse infinitely in convert. */ - if (TYPE_PRECISION (typex) != inprec) - { - /* Don't do unsigned arithmetic where signed was wanted, - or vice versa. */ - typex = (TREE_UNSIGNED (TREE_TYPE (expr)) - ? unsigned_type (typex) : signed_type (typex)); - return convert (type, - build_unary_op (ex_form, - convert (typex, TREE_OPERAND (expr, 0)), - 1)); - } - } - - case NOP_EXPR: - /* If truncating after truncating, might as well do all at once. - If truncating after extending, we may get rid of wasted work. */ - return convert (type, get_unwidened (TREE_OPERAND (expr, 0), type)); - - case COND_EXPR: - /* Can treat the two alternative values like the operands - of an arithmetic expression. */ - { - tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type); - tree arg2 = get_unwidened (TREE_OPERAND (expr, 2), type); - - if (outprec >= BITS_PER_WORD - || TRULY_NOOP_TRUNCATION (outprec, inprec) - || inprec > TYPE_PRECISION (TREE_TYPE (arg1)) - || inprec > TYPE_PRECISION (TREE_TYPE (arg2))) - { - /* Do the arithmetic in type TYPEX, - then convert result to TYPE. */ - register tree typex = type; - - /* Can't do arithmetic in enumeral types - so use an integer type that will hold the values. */ - if (TREE_CODE (typex) == ENUMERAL_TYPE) - typex = type_for_size (TYPE_PRECISION (typex), - TREE_UNSIGNED (typex)); - - /* But now perhaps TYPEX is as wide as INPREC. - In that case, do nothing special here. - (Otherwise would recurse infinitely in convert. */ - if (TYPE_PRECISION (typex) != inprec) - { - /* Don't do unsigned arithmetic where signed was wanted, - or vice versa. */ - typex = (TREE_UNSIGNED (TREE_TYPE (expr)) - ? unsigned_type (typex) : signed_type (typex)); - return convert (type, - fold (build (COND_EXPR, typex, - TREE_OPERAND (expr, 0), - convert (typex, arg1), - convert (typex, arg2)))); - } - else - /* It is sometimes worthwhile - to push the narrowing down through the conditional. */ - return fold (build (COND_EXPR, type, - TREE_OPERAND (expr, 0), - convert (type, TREE_OPERAND (expr, 1)), - convert (type, TREE_OPERAND (expr, 2)))); - } - } - } - - return build1 (NOP_EXPR, type, expr); - } - - if (form == REAL_TYPE) - return build1 (FIX_TRUNC_EXPR, type, expr); - - error ("aggregate value used where an integer was expected"); - - { - register tree tem = build_int_2 (0, 0); - TREE_TYPE (tem) = type; - return tem; - } -} /* Create an expression whose value is that of EXPR, converted to type TYPE. The TREE_TYPE of the value @@ -380,12 +61,14 @@ tree convert (type, expr) tree type, expr; { - register tree e = expr; - register enum tree_code code = TREE_CODE (type); + tree e = expr; + enum tree_code code = TREE_CODE (type); if (type == TREE_TYPE (expr) - || TREE_CODE (expr) == ERROR_MARK) + || TREE_CODE (expr) == ERROR_MARK + || code == ERROR_MARK || TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK) return expr; + if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr))) return fold (build1 (NOP_EXPR, type, expr)); if (TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK) @@ -405,10 +88,24 @@ convert (type, expr) #endif if (code == INTEGER_TYPE || code == ENUMERAL_TYPE) return fold (convert_to_integer (type, e)); - if (code == POINTER_TYPE) + if (code == BOOLEAN_TYPE) + { + tree t = truthvalue_conversion (expr); + /* If truthvalue_conversion returns a NOP_EXPR, we must fold it here + to avoid infinite recursion between fold () and convert (). */ + if (TREE_CODE (t) == NOP_EXPR) + return fold (build1 (NOP_EXPR, type, TREE_OPERAND (t, 0))); + else + return fold (build1 (NOP_EXPR, type, t)); + } + if (code == POINTER_TYPE || code == REFERENCE_TYPE) return fold (convert_to_pointer (type, e)); if (code == REAL_TYPE) return fold (convert_to_real (type, e)); + if (code == COMPLEX_TYPE) + return fold (convert_to_complex (type, e)); + if (code == VECTOR_TYPE) + return fold (convert_to_vector (type, e)); error ("conversion to non-scalar type requested"); return error_mark_node;