/* Utility routines for data type conversion for GNU C.
- Copyright (C) 1987, 1988, 1991, 1992 Free Software Foundation, Inc.
+ Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1997,
+ 1998 Free Software Foundation, Inc.
This file is part of GNU C.
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. */
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA. */
/* These routines are somewhat language-independent utility function
- intended to be called by the language-specific convert () functions. */
+ intended to be called by the language-specific convert () functions. */
#include "config.h"
+#include "system.h"
#include "tree.h"
#include "flags.h"
#include "convert.h"
+#include "toplev.h"
-/* Convert EXPR to some pointer type TYPE.
+/* Convert EXPR to some pointer or reference type TYPE.
- EXPR must be pointer, integer, enumeral, or literal zero;
- in other cases error is called. */
+ EXPR must be pointer, reference, integer, enumeral, or literal zero;
+ in other cases error is called. */
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)
+ switch (TREE_CODE (TREE_TYPE (expr)))
{
- if (type_precision (intype) == POINTER_SIZE)
+ case POINTER_TYPE:
+ case REFERENCE_TYPE:
+ return build1 (NOP_EXPR, type, expr);
+
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ case BOOLEAN_TYPE:
+ case CHAR_TYPE:
+ if (TYPE_PRECISION (TREE_TYPE (expr)) == POINTER_SIZE)
return build1 (CONVERT_EXPR, type, expr);
- expr = convert (type_for_size (POINTER_SIZE, 0), expr);
- /* Modes may be different but sizes should be the same. */
- if (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr)))
- != GET_MODE_SIZE (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
+ convert_to_pointer (type,
+ convert (type_for_size (POINTER_SIZE, 0), expr));
- return null_pointer_node;
+ default:
+ error ("cannot convert to a pointer type");
+ return convert_to_pointer (type, integer_zero_node);
+ }
}
/* Convert EXPR to some floating-point type TYPE.
EXPR must be float, integer, or enumeral;
- in other cases error is called. */
+ in other cases error is called. */
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 == COMPLEX_TYPE)
- return convert (type, fold (build1 (REALPART_EXPR,
- TREE_TYPE (TREE_TYPE (expr)), expr)));
-
- if (form == POINTER_TYPE)
- error ("pointer value used where a floating point value 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", TYPE_MODE (type));
- return tem;
- }
+ switch (TREE_CODE (TREE_TYPE (expr)))
+ {
+ case REAL_TYPE:
+ return build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
+ type, expr);
+
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ case BOOLEAN_TYPE:
+ case CHAR_TYPE:
+ return build1 (FLOAT_EXPR, type, expr);
+
+ case COMPLEX_TYPE:
+ return convert (type,
+ fold (build1 (REALPART_EXPR,
+ TREE_TYPE (TREE_TYPE (expr)), expr)));
+
+ case POINTER_TYPE:
+ case REFERENCE_TYPE:
+ error ("pointer value used where a floating point value was expected");
+ return convert_to_real (type, integer_zero_node);
+
+ default:
+ error ("aggregate value used where a float was expected");
+ return convert_to_real (type, integer_zero_node);
+ }
}
/* Convert EXPR to some integer (or enum) type TYPE.
convert_to_integer (type, expr)
tree type, expr;
{
- register tree intype = TREE_TYPE (expr);
- register enum tree_code form = TREE_CODE (intype);
+ enum tree_code ex_form = TREE_CODE (expr);
+ tree intype = TREE_TYPE (expr);
+ unsigned int inprec = TYPE_PRECISION (intype);
+ unsigned int outprec = TYPE_PRECISION (type);
+
+ /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can
+ be. Consider `enum E = { a, b = (enum E) 3 };'. */
+ if (!COMPLETE_TYPE_P (type))
+ {
+ error ("conversion to incomplete type");
+ return error_mark_node;
+ }
- if (form == POINTER_TYPE)
+ switch (TREE_CODE (intype))
{
+ case POINTER_TYPE:
+ case REFERENCE_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
- || form == BOOLEAN_TYPE || form == CHAR_TYPE)
- {
- register unsigned outprec = TYPE_PRECISION (type);
- register unsigned inprec = TYPE_PRECISION (intype);
- register enum tree_code ex_form = TREE_CODE (expr);
+ return convert_to_integer (type, 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_XOR_EXPR || ex_form == TRUTH_NOT_EXPR)
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ case BOOLEAN_TYPE:
+ case CHAR_TYPE:
+ /* If this is a logical operation, which just returns 0 or 1, we can
+ change the type of the expression. For some logical operations,
+ we must also change the types of the operands to maintain type
+ correctness. */
+
+ if (TREE_CODE_CLASS (ex_form) == '<')
{
TREE_TYPE (expr) = type;
return expr;
}
+
+ else if (ex_form == TRUTH_AND_EXPR || ex_form == TRUTH_ANDIF_EXPR
+ || ex_form == TRUTH_OR_EXPR || ex_form == TRUTH_ORIF_EXPR
+ || ex_form == TRUTH_XOR_EXPR)
+ {
+ TREE_OPERAND (expr, 0) = convert (type, TREE_OPERAND (expr, 0));
+ TREE_OPERAND (expr, 1) = convert (type, TREE_OPERAND (expr, 1));
+ TREE_TYPE (expr) = type;
+ return expr;
+ }
+
+ else if (ex_form == TRUTH_NOT_EXPR)
+ {
+ TREE_OPERAND (expr, 0) = convert (type, TREE_OPERAND (expr, 0));
+ TREE_TYPE (expr) = type;
+ return expr;
+ }
+
+ /* If we are widening the type, put in an explicit conversion.
+ Similarly if we are not changing the width. After this, we know
+ we are truncating 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. */
+ /* If TYPE is an enumeral type or a type with a precision less
+ than the number of bits in its mode, do the conversion to the
+ type corresponding to its mode, then do a nop conversion
+ to TYPE. */
+ else if (TREE_CODE (type) == ENUMERAL_TYPE
+ || outprec != GET_MODE_BITSIZE (TYPE_MODE (type)))
+ return build1 (NOP_EXPR, type,
+ convert (type_for_mode (TYPE_MODE (type),
+ TREE_UNSIGNED (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)
{
/* 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))
+ && tree_int_cst_lt (TREE_OPERAND (expr, 1),
+ convert (TREE_TYPE (TREE_OPERAND (expr, 1)),
+ integer_one_node)))
goto trunc1;
break;
/* 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_int_cst_sgn (TREE_OPERAND (expr, 1)) >= 0
&& TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST)
{
/* If shift count is less than the width of the truncated 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);
+ {
+ /* 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. */
+
+ tree t = convert_to_integer (type, integer_zero_node);
+
+ /* If the original expression had side-effects, we must
+ preserve it. */
+ if (TREE_SIDE_EFFECTS (expr))
+ return build (COMPOUND_EXPR, type, expr, t);
+ else
+ return t;
+ }
}
break;
case NEGATE_EXPR:
case BIT_NOT_EXPR:
- case ABS_EXPR:
+ /* This is not correct for ABS_EXPR,
+ since we must test the sign before truncation. */
{
register tree typex = type;
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))));
- }
- }
+ /* It is sometimes worthwhile to push the narrowing down through
+ the conditional and never loses. */
+ return fold (build (COND_EXPR, type, TREE_OPERAND (expr, 0),
+ convert (type, TREE_OPERAND (expr, 1)),
+ convert (type, TREE_OPERAND (expr, 2))));
+ default:
+ break;
}
return build1 (NOP_EXPR, type, expr);
- }
- if (form == REAL_TYPE)
- return build1 (FIX_TRUNC_EXPR, type, expr);
+ case REAL_TYPE:
+ return build1 (FIX_TRUNC_EXPR, type, expr);
- if (form == COMPLEX_TYPE)
- return convert (type, fold (build1 (REALPART_EXPR,
- TREE_TYPE (TREE_TYPE (expr)), expr)));
+ case COMPLEX_TYPE:
+ return convert (type,
+ fold (build1 (REALPART_EXPR,
+ TREE_TYPE (TREE_TYPE (expr)), expr)));
- error ("aggregate value used where an integer was expected");
-
- {
- register tree tem = build_int_2 (0, 0);
- TREE_TYPE (tem) = type;
- return tem;
- }
+ default:
+ error ("aggregate value used where an integer was expected");
+ return convert (type, integer_zero_node);
+ }
}
/* Convert EXPR to the complex type TYPE in the usual ways. */
convert_to_complex (type, expr)
tree type, expr;
{
- register enum tree_code form = TREE_CODE (TREE_TYPE (expr));
tree subtype = TREE_TYPE (type);
- if (form == REAL_TYPE || form == INTEGER_TYPE || form == ENUMERAL_TYPE)
+ switch (TREE_CODE (TREE_TYPE (expr)))
{
- expr = convert (subtype, expr);
- return build (COMPLEX_EXPR, type, expr,
+ case REAL_TYPE:
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ case BOOLEAN_TYPE:
+ case CHAR_TYPE:
+ return build (COMPLEX_EXPR, type, convert (subtype, expr),
convert (subtype, integer_zero_node));
- }
- if (form == COMPLEX_TYPE)
- {
- tree elt_type = TREE_TYPE (TREE_TYPE (expr));
- if (TYPE_MAIN_VARIANT (elt_type) == TYPE_MAIN_VARIANT (subtype))
- return expr;
- else if (TREE_CODE (expr) == COMPLEX_EXPR)
- return fold (build (COMPLEX_EXPR,
- type,
- convert (subtype, TREE_OPERAND (expr, 0)),
- convert (subtype, TREE_OPERAND (expr, 1))));
- else
- {
- expr = save_expr (expr);
+ case COMPLEX_TYPE:
+ {
+ tree elt_type = TREE_TYPE (TREE_TYPE (expr));
+
+ if (TYPE_MAIN_VARIANT (elt_type) == TYPE_MAIN_VARIANT (subtype))
+ return expr;
+ else if (TREE_CODE (expr) == COMPLEX_EXPR)
return fold (build (COMPLEX_EXPR,
type,
- convert (subtype,
- fold (build1 (REALPART_EXPR,
- TREE_TYPE (TREE_TYPE (expr)),
- expr))),
- convert (subtype,
- fold (build1 (IMAGPART_EXPR,
- TREE_TYPE (TREE_TYPE (expr)),
- expr)))));
- }
- }
+ convert (subtype, TREE_OPERAND (expr, 0)),
+ convert (subtype, TREE_OPERAND (expr, 1))));
+ else
+ {
+ expr = save_expr (expr);
+ return
+ fold (build (COMPLEX_EXPR,
+ type, convert (subtype,
+ fold (build1 (REALPART_EXPR,
+ TREE_TYPE (TREE_TYPE (expr)),
+ expr))),
+ convert (subtype,
+ fold (build1 (IMAGPART_EXPR,
+ TREE_TYPE (TREE_TYPE (expr)),
+ expr)))));
+ }
+ }
- if (form == POINTER_TYPE)
- error ("pointer value used where a complex was expected");
- else
- error ("aggregate value used where a complex was expected");
-
- return build (COMPLEX_EXPR, type,
- convert (subtype, integer_zero_node),
- convert (subtype, integer_zero_node));
+ case POINTER_TYPE:
+ case REFERENCE_TYPE:
+ error ("pointer value used where a complex was expected");
+ return convert_to_complex (type, integer_zero_node);
+
+ default:
+ error ("aggregate value used where a complex was expected");
+ return convert_to_complex (type, integer_zero_node);
+ }
}
OSDN Git Service
