a4cd5630b0
non-i386, non-unix, and generatable files have been trimmed, but can easily be added in later if needed. gcc-2.7.2.1 will follow shortly, it's a very small delta to this and it's handy to have both available for reference for such little cost. The freebsd-specific changes will then be committed, and once the dust has settled, the bmakefiles will be committed to use this code.
473 lines
15 KiB
C
473 lines
15 KiB
C
/* Utility routines for data type conversion for GNU C.
|
|
Copyright (C) 1987, 88, 91, 92, 94, 1995 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU C.
|
|
|
|
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.
|
|
|
|
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.
|
|
|
|
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, 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. */
|
|
|
|
#include "config.h"
|
|
#include "tree.h"
|
|
#include "flags.h"
|
|
#include "convert.h"
|
|
|
|
/* Convert EXPR to some pointer or reference type TYPE.
|
|
|
|
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))
|
|
{
|
|
expr = build_int_2 (0, 0);
|
|
TREE_TYPE (expr) = type;
|
|
return expr;
|
|
}
|
|
|
|
if (form == POINTER_TYPE || form == REFERENCE_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);
|
|
/* 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");
|
|
|
|
expr = build_int_2 (0, 0);
|
|
TREE_TYPE (expr) = type;
|
|
return expr;
|
|
}
|
|
|
|
/* Convert EXPR to some floating-point type TYPE.
|
|
|
|
EXPR must be float, integer, or enumeral;
|
|
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 (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
|
|
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 || form == REFERENCE_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;
|
|
}
|
|
}
|
|
|
|
/* Convert EXPR to some integer (or enum) type TYPE.
|
|
|
|
EXPR must be pointer, integer, discrete (enum, char, or bool), or float;
|
|
in other cases error is called.
|
|
|
|
The result of this is always supposed to be a newly created tree node
|
|
not in use in any existing structure. */
|
|
|
|
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 || form == 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);
|
|
|
|
/* 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. For 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;
|
|
}
|
|
else if (outprec >= inprec)
|
|
return build1 (NOP_EXPR, type, expr);
|
|
|
|
/* 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)
|
|
{
|
|
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),
|
|
convert (TREE_TYPE (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_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,
|
|
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. */
|
|
|
|
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 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,
|
|
fold (build (ex_form, typex,
|
|
convert (typex, arg0),
|
|
convert (typex, arg1),
|
|
0)));
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
|
|
case NEGATE_EXPR:
|
|
case BIT_NOT_EXPR:
|
|
/* This is not correct for ABS_EXPR,
|
|
since we must test the sign before truncation. */
|
|
{
|
|
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 (build1 (ex_form, typex,
|
|
convert (typex,
|
|
TREE_OPERAND (expr, 0)))));
|
|
}
|
|
}
|
|
|
|
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);
|
|
|
|
if (form == 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;
|
|
}
|
|
}
|
|
|
|
/* Convert EXPR to the complex type TYPE in the usual ways. */
|
|
|
|
tree
|
|
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)
|
|
{
|
|
expr = convert (subtype, expr);
|
|
return build (COMPLEX_EXPR, type, 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);
|
|
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 || form == REFERENCE_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));
|
|
}
|