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/******************************** -*- C -*- ****************************
*
* Byte code interpreter inlines
*
*
***********************************************************************/
/***********************************************************************
*
* Copyright 2000, 2001, 2002, 2006 Free Software Foundation, Inc.
* Written by Steve Byrne.
*
* This file is part of GNU Smalltalk.
*
* GNU Smalltalk 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.
*
* Linking GNU Smalltalk statically or dynamically with other modules is
* making a combined work based on GNU Smalltalk. Thus, the terms and
* conditions of the GNU General Public License cover the whole
* combination.
*
* In addition, as a special exception, the Free Software Foundation
* give you permission to combine GNU Smalltalk with free software
* programs or libraries that are released under the GNU LGPL and with
* independent programs running under the GNU Smalltalk virtual machine.
*
* You may copy and distribute such a system following the terms of the
* GNU GPL for GNU Smalltalk and the licenses of the other code
* concerned, provided that you include the source code of that other
* code when and as the GNU GPL requires distribution of source code.
*
* Note that people who make modified versions of GNU Smalltalk are not
* obligated to grant this special exception for their modified
* versions; it is their choice whether to do so. The GNU General
* Public License gives permission to release a modified version without
* this exception; this exception also makes it possible to release a
* modified version which carries forward this exception.
*
* GNU Smalltalk 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 Smalltalk; see the file COPYING. If not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
***********************************************************************/
/* Multiply a*b and in case of an overflow, answer OVERFLOWING_INT so
that we can work it out the same way we do with adds and
subtracts. */
static inline intptr_t mul_with_check (intptr_t a, intptr_t b);
/* using STACK_AT is correct: numArgs == 0 means that there's just the
* receiver on the stack, at 0. numArgs = 1 means that at location 0 is
* the arg, location 1 is the receiver. And so on. */
#define SEND_MESSAGE(sendSelector, sendArgs) do { \
OOP _receiver; \
_receiver = STACK_AT(sendArgs); \
_gst_send_message_internal(sendSelector, sendArgs, _receiver, \
OOP_INT_CLASS(_receiver)); \
} while(0)
intptr_t
mul_with_check (intptr_t a, intptr_t b)
{
intmax_t result = (intmax_t)a * b;
/* We define the largest int type in stdintx.h, but we can
only use it if it is two times the width of an intptr_t. */
if (sizeof (intmax_t) >= 2 * sizeof (intptr_t))
{
if UNCOMMON (result > MAX_ST_INT || result < MIN_ST_INT)
return (OVERFLOWING_INT);
else
return (result);
}
/* This fallback method uses a division to do overflow check */
else
{
if COMMON (((uintptr_t) (a | b)) < (1L << (ST_INT_SIZE / 2))
|| b == 0
|| result / b == a)
return (result);
else
return (OVERFLOWING_INT);
}
}
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