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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 /*
     22  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 	.file	"_xtoull.s"
     27 
     28 #include <SYS.h>
     29 
     30 	.set	cw,0
     31 	.set	cw_old,2
     32 	.text
     33 	.align	16
     34 two_to_63: .4byte	0x5f000000
     35 
     36 	ENTRY(__xtoull)	/* 387-stack to unsigned long long */
     37 	subq	$16,%rsp
     38 	fstcw	cw_old(%rsp)
     39 	movw	cw_old(%rsp),%ax
     40 	movw	%ax,%cx
     41 	andw	$0x0c00,%cx		/* save RC */
     42 	orw	$0x0c00,%ax
     43 	movw	%ax,cw(%rsp)
     44 	fldcw	cw(%rsp)
     45 	flds	two_to_63(%rip)
     46 	fcomip	%st(1),%st		/* compare 2**63 to x */
     47 	jp	.donotsub		/* jump if x is NaN */
     48 	ja	.donotsub		/* jump if 2**63 > x */
     49 	fsubs	two_to_63(%rip)		/* subtract 2**63 */
     50 .donotsub:
     51 	fistpll	8(%rsp)
     52 	fwait				/* in case fistpll causes exception */
     53 	movq	8(%rsp),%rax
     54 	jp	.donotadd
     55 	ja	.donotadd		/* flags did not change */
     56 	movq	$0x8000000000000000,%rcx
     57 	addq	%rcx,%rax		/* add back 2**63 */
     58 .donotadd:
     59 	fstcw	cw(%rsp)		/* fetch CW in case masks changed */
     60 	movw	cw(%rsp),%dx
     61 	andw	$0xf3ff,%dx
     62 	orw	%cx,%dx			/* restore RC */
     63 	movw	%dx,cw(%rsp)
     64 	fldcw	cw(%rsp)
     65 	addq	$16,%rsp
     66 	ret
     67 	SET_SIZE(__xtoull)
     68