xref: /illumos-gate/usr/src/lib/libc/amd64/threads/tls_get_addr.S (revision 5d9d9091f564c198a760790b0bfa72c44e17912b)
1*5d9d9091SRichard Lowe/*
2*5d9d9091SRichard Lowe * CDDL HEADER START
3*5d9d9091SRichard Lowe *
4*5d9d9091SRichard Lowe * The contents of this file are subject to the terms of the
5*5d9d9091SRichard Lowe * Common Development and Distribution License (the "License").
6*5d9d9091SRichard Lowe * You may not use this file except in compliance with the License.
7*5d9d9091SRichard Lowe *
8*5d9d9091SRichard Lowe * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9*5d9d9091SRichard Lowe * or http://www.opensolaris.org/os/licensing.
10*5d9d9091SRichard Lowe * See the License for the specific language governing permissions
11*5d9d9091SRichard Lowe * and limitations under the License.
12*5d9d9091SRichard Lowe *
13*5d9d9091SRichard Lowe * When distributing Covered Code, include this CDDL HEADER in each
14*5d9d9091SRichard Lowe * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15*5d9d9091SRichard Lowe * If applicable, add the following below this CDDL HEADER, with the
16*5d9d9091SRichard Lowe * fields enclosed by brackets "[]" replaced with your own identifying
17*5d9d9091SRichard Lowe * information: Portions Copyright [yyyy] [name of copyright owner]
18*5d9d9091SRichard Lowe *
19*5d9d9091SRichard Lowe * CDDL HEADER END
20*5d9d9091SRichard Lowe */
21*5d9d9091SRichard Lowe/*
22*5d9d9091SRichard Lowe * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
23*5d9d9091SRichard Lowe * Use is subject to license terms.
24*5d9d9091SRichard Lowe */
25*5d9d9091SRichard Lowe
26*5d9d9091SRichard Lowe	.file	"tls_get_addr.s"
27*5d9d9091SRichard Lowe
28*5d9d9091SRichard Lowe/*
29*5d9d9091SRichard Lowe * To make thread-local storage accesses as fast as possible, we
30*5d9d9091SRichard Lowe * hand-craft the __tls_get_addr() function below, from this C code:
31*5d9d9091SRichard Lowe * void *
32*5d9d9091SRichard Lowe * __tls_get_addr(TLS_index *tls_index)
33*5d9d9091SRichard Lowe * {
34*5d9d9091SRichard Lowe *	ulwp_t *self = curthread;
35*5d9d9091SRichard Lowe *	tls_t *tlsent = self->ul_tlsent;
36*5d9d9091SRichard Lowe *	ulong_t moduleid;
37*5d9d9091SRichard Lowe *	caddr_t	base;
38*5d9d9091SRichard Lowe *
39*5d9d9091SRichard Lowe *	if ((moduleid = tls_index->ti_moduleid) < self->ul_ntlsent &&
40*5d9d9091SRichard Lowe *	    (base = tlsent[moduleid].tls_data) != NULL)
41*5d9d9091SRichard Lowe *		return (base + tls_index->ti_tlsoffset);
42*5d9d9091SRichard Lowe *
43*5d9d9091SRichard Lowe *	return (slow_tls_get_addr(tls_index));
44*5d9d9091SRichard Lowe * }
45*5d9d9091SRichard Lowe *
46*5d9d9091SRichard Lowe * ___tls_get_addr() is identical to __tls_get_addr() except that it
47*5d9d9091SRichard Lowe * assumes its argument is passed in %eax rather than on the stack.
48*5d9d9091SRichard Lowe */
49*5d9d9091SRichard Lowe
50*5d9d9091SRichard Lowe#include "SYS.h"
51*5d9d9091SRichard Lowe#include <../assym.h>
52*5d9d9091SRichard Lowe
53*5d9d9091SRichard Lowe	ENTRY_NP(__tls_get_addr)
54*5d9d9091SRichard Lowe	ALTENTRY(___tls_get_addr)
55*5d9d9091SRichard Lowe	movq	%fs:UL_TLSENT, %rax
56*5d9d9091SRichard Lowe	movq	TI_MODULEID (%rdi), %rdx
57*5d9d9091SRichard Lowe	cmpq	%fs:UL_NTLSENT, %rdx
58*5d9d9091SRichard Lowe	jae	slow_tls_get_addr	/* tail call */
59*5d9d9091SRichard Lowe	/* movq	TLS_DATA (%rax,%rdx,SIZEOF_TLS_T), %rax */
60*5d9d9091SRichard Lowe	shlq	$4, %rdx	/* SIZEOF_TLS_T == 16 */
61*5d9d9091SRichard Lowe	movq	TLS_DATA (%rax,%rdx), %rax
62*5d9d9091SRichard Lowe	testq	%rax, %rax
63*5d9d9091SRichard Lowe	je	slow_tls_get_addr	/* tail call */
64*5d9d9091SRichard Lowe	addq	TI_TLSOFFSET (%rdi), %rax
65*5d9d9091SRichard Lowe	ret
66*5d9d9091SRichard Lowe	SET_SIZE(___tls_get_addr)
67*5d9d9091SRichard Lowe	SET_SIZE(__tls_get_addr)
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