fplib_glue.s

来自「基于组件方式开发操作系统的OSKIT源代码」· S 代码 · 共 160 行

/*	$NetBSD: fplib_glue.S,v 1.1 1997/10/12 21:18:08 mark Exp $	*/

/*-
 * Copyright (c) 1997 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Neil A. Carson and Mark Brinicombe
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <oskit/machine/asm.h>

#define SIGN_BIT_TWIDDLE	0x80000000

/********************************* COMPARISONS ********************************/

/*
 * 'Equal' wrapper. This returns 0 if the numbers are equal, or (1 | -1)
 * otherwise. So we need to invert the output.
 */
ENTRY(__eqsf2)
	stmfd		sp!, {lr}
	bl		EXT(float32_eq)
	eor		r0, r0, #1
	ldmfd		sp!, {pc}

ENTRY(__eqdf2)
	stmfd		sp!, {lr}
	bl		EXT(float64_eq)
	eor		r0, r0, #1
	ldmfd		sp!, {pc}

/*
 * 'Not Equal' wrapper. This returns -1 or 1 (say, 1!) if the numbers are
 * not equal, 0 otherwise. However no not equal call is provided, so we have
 * to use an 'equal' call and invert the result. The result is already
 * inverted though! Confusing?!
 */
ENTRY(__nesf2)
	stmfd		sp!, {lr}
	bl		EXT(float32_eq)
	eor		r0, r0, #1
	ldmfd		sp!, {pc}

ENTRY(__nedf2)
	stmfd		sp!, {lr}
	bl		EXT(float64_eq)
	eor		r0, r0, #1
	ldmfd		sp!, {pc}

/*
 * 'Greater Than' wrapper. This returns 1 if the number is greater, 0
 * or -1 otherwise. Unfortunately, no such function exists. We have to
 * instead compare the numbers using the 'less than' calls in order to
 * make up our mind. This means that we can call 'less than or equal' and
 * invert the result.
 */
ENTRY(__gtsf2)
	stmfd		sp!, {lr}
	bl		EXT(float32_le)
	eor		r0, r0, #1
	ldmfd		sp!, {pc}

ENTRY(__gtdf2)
	stmfd		sp!, {lr}
	bl		EXT(float64_le)
	eor		r0, r0, #1
	ldmfd		sp!, {pc}

/*
 * 'Greater Than or Equal' wrapper. We emulate this by inverting the result
 * of a 'less than' call.
 */
ENTRY(__gesf2)
	stmfd		sp!, {lr}
	bl		EXT(float32_lt)
	eor		r0, r0, #1
	cmp		r0, #0
	mvneq		r0, #0
	ldmfd		sp!, {pc}

ENTRY(__gedf2)
	stmfd		sp!, {lr}
	bl		EXT(float64_lt)
	eor		r0, r0, #1
	cmp		r0, #0
	mvneq		r0, #0
	ldmfd		sp!, {pc}

/*
 * 'Less Than' wrapper. A 1 from the ARM code needs to be turned into -1.
 */
ENTRY(__ltsf2)
	stmfd		sp!, {lr}
	bl		EXT(float32_lt)
	cmp		r0, #1
	mvneq		r0, #0
	ldmfd		sp!, {pc}

ENTRY(__ltdf2)
	stmfd		sp!, {lr}
	bl		EXT(float64_lt)
	cmp		r0, #1
	mvneq		r0, #0
	ldmfd		sp!, {pc}

/*
 * 'Less Than or Equal' wrapper. A 0 must turn into a 1, and a 1 into a 0.
 */
ENTRY(__lesf2)
	stmfd		sp!, {lr}
	bl		EXT(float32_le)
	eor		r0, r0, #1
	ldmfd		sp!, {pc}

ENTRY(__ledf2)
	stmfd		sp!, {lr}
	bl		EXT(float64_le)
	eor		r0, r0, #1
	ldmfd		sp!, {pc}

/*
 * Float negate... This isn't provided by the library, but it's hardly the
 * hardest function in the world to write... :) In fact, because of the
 * position in the registers of arguments, the double precision version can
 * go here too ;-)
 */
ENTRY(__negsf2)
ENTRY(__negdf2)
	eor		r0, r0, #SIGN_BIT_TWIDDLE
	mov		pc, lr