25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER START
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * The contents of this file are subject to the terms of the
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Common Development and Distribution License (the "License").
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * You may not use this file except in compliance with the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * or http://www.opensolaris.org/os/licensing.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * See the License for the specific language governing permissions
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * and limitations under the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER END
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Use is subject to license terms.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis .file "round.s"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "libm.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr JasiukajtisLIBM_ANSI_PRAGMA_WEAK(round,function)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis .section .rodata
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis .align 4
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis.Lhalf: .float 0.5
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ENTRY(round)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis movl %esp,%ecx
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis subl $8,%esp
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fstcw -8(%ecx)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fldl 4(%ecx)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis movw -8(%ecx),%dx
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis andw $0xf3ff,%dx
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis movw %dx,-4(%ecx)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fldcw -4(%ecx) / set RD = to_nearest
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fld %st(0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis frndint / [x],x
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fstcw -4(%ecx)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis movw -4(%ecx),%dx
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis andw $0xf3ff,%dx
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis movw -8(%ecx),%ax
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis andw $0x0c00,%ax
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis orw %dx,%ax
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis movw %ax,-8(%ecx)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fldcw -8(%ecx) / restore RD
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fucom / check if x is already an integer
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fstsw %ax
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis sahf
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis jp 0f
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis je 0f
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fxch / x,[x]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fsub %st(1),%st / x-[x],[x]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fabs / |x-[x]|,[x]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis PIC_SETUP(1)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fcoms PIC_L(.Lhalf)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis PIC_WRAPUP
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fnstsw %ax
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis sahf
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis jae 2f / if |x-[x]| = 0.5 goto halfway,
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis / most cases will not take branch.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis0:
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis addl $8,%esp
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fstp %st(0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ret
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis2:
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis / x = n+0.5, recompute round(x) as x+sign(x)*0.5
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fldl 4(%ecx) / x, 0.5, [x]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis movl 8(%ecx),%eax / high part of x
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis andl $0x80000000,%eax
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis jnz 3f
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis faddp
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis addl $8,%esp
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fstp %st(1)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ret
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis3:
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis / here, x is negative, so return x-0.5
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fsubp %st,%st(1) / x-0.5,[x]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis addl $8,%esp
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis fstp %st(1)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ret
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis .align 4
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis SET_SIZE(round)