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libjit/attic/jit-rules-alpha.c  view on Meta::CPAN

/*
 * jit-rules-alpha.c - Rules that define the characteristics of the alpha.
 *
 * Copyright (C) 2006  Southern Storm Software, Pty Ltd.
 *
 * This file is part of the libjit library.
 *
 * The libjit library is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation, either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * The libjit library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the libjit library.  If not, see
 * <http://www.gnu.org/licenses/>.
 */

#include "jit-internal.h"
#include "jit-rules.h"
#include "jit-apply-rules.h"

#if defined(JIT_BACKEND_ALPHA)

#include "jit-elf-defs.h"
#include "jit-gen-alpha.h"
#include "jit-reg-alloc.h"
#include "jit-setjmp.h"
#include <stdio.h>

/*
 * _alpha_has_ieeefp()
 *
 * When the Alpha architecture's floating point unit was first designed, 
 * the designers traded performance for functionality. As a result, all 
 * Alpha systems below EV6 do not fully implement the IEEE floating 
 * point standard. For those earlier systems, there is no hardware 
 * support for denormalized numbers or exceptional IEEE values like not 
 * a number and positive/negative infinity. For systems without hardware
 * support, the kernal can assist, but more you'll need to add 
 * instructions to trap into the kernel. Use this function to determine
 * if hardware ieeefp is available.
 *
 * To get the kernel to assist when needed, use the following code:
 *
 *	if (!_alpha_has_ieeefp())
 *		alpha_trapb(inst);
 *
 * RETURN VALUE:
 *  - TRUE if the CPU fully supports IEEE floating-point (i.e. >=ev6)
 *  - FALSE if the CPU needs kernel assistance
 */
int _alpha_has_ieeefp() {
        unsigned long __implver;

	/*
	 * __implver - major version number of the processor
	 *
	 * (__implver == 0)	ev4 class processors
	 * (__implver == 1)	ev5 class processors
	 * (__implver == 2)	ev6 class processors
	 */
        __asm__ ("implver %0" : "=r"(__implver));
	return (__implver >= 2);
}

/*
 * Round a size up to a multiple of the stack word size.
 */
#define ROUND_STACK(size)       \
	(((size) + (sizeof(alpha_inst) - 1)) & ~(sizeof(alpha_inst) - 1))


/*
 * Setup or teardown the alpha code output process.
 */