[thirdparty/glibc.git] / nptl / sysdeps / unix / sysv / linux / x86_64 / pthread_once.S

/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C 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 GNU C 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 GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef UP
# define LOCK lock
#else
# define LOCK
#endif

#define SYS_futex	202
#define FUTEX_WAKE	1

	.comm	__fork_generation, 4, 4

	.text


	.globl	__pthread_once
	.type	__pthread_once,@function
	.align	16
__pthread_once:
.LSTARTCODE:
	testl	$2, (%rdi)
	jz	1f
	xorl	%eax, %eax
	retq

	/* Preserve the function pointer.  */
1:	pushq	%rsi
.Lpush_rsi:
	xorq	%r10, %r10

	/* Not yet initialized or initialization in progress.
	   Get the fork generation counter now.  */
6:	movl	(%rdi), %eax

5:	movl	%eax, %edx

	testl	$2, %eax
	jnz	4f

	andl	$3, %edx
	orl	__fork_generation(%rip), %edx
	orl	$1, %edx

	LOCK
	cmpxchgl %edx, (%rdi)
	jnz	5b

	/* Check whether another thread already runs the initializer.  */
	testl	$1, %eax
	jz	3f	/* No -> do it.  */

	/* Check whether the initializer execution was interrupted
	   by a fork.  */
	xorl	%edx, %eax
	testl	$0xfffffffc, %eax
	jnz	3f	/* Different for generation -> run initializer.  */

	/* Somebody else got here first.  Wait.  */
	movq	%r10, %rsi		/* movq $FUTEX_WAIT, %rsi */
	movq	$SYS_futex, %rax
	syscall
	jmp	6b

	/* Preserve the pointer to the control variable.  */
3:	pushq	%rdi
.Lpush_rdi:

.LcleanupSTART:
	callq	*8(%rsp)
.LcleanupEND:

	/* Get the control variable address back.  */
	popq	%rdi
.Lpop_rdi:

	/* Sucessful run of the initializer.  Signal that we are done.  */
	LOCK
	incl	(%rdi)

	/* Wake up all other threads.  */
	movl	$0x7fffffff, %edx
	movl	$FUTEX_WAKE, %esi
	movq	$SYS_futex, %rax
	syscall

4:	addq	$8, %rsp
.Ladd:
	xorq	%rax, %rax
	retq

	.size	__pthread_once,.-__pthread_once


	.globl	__pthread_once_internal
__pthread_once_internal = __pthread_once

	.globl	pthread_once
pthread_once = __pthread_once


	.type	clear_once_control,@function
	.align	16
clear_once_control:
	movq	(%rsp), %rdi
	movq	%rax, %r8
	movl	$0, (%rdi)

	movl	$0x7fffffff, %edx
	movq	$FUTEX_WAKE, %rsi
	movq	$SYS_futex, %rax
	syscall

	movq	%r8, %rdi
.LcallUR:
	call	_Unwind_Resume@PLT
	hlt
.LENDCODE:
	.size	clear_once_control,.-clear_once_control


	.section .gcc_except_table,"a",@progbits
.LexceptSTART:
	.byte	0xff				# @LPStart format (omit)
	.byte	0xff				# @TType format (omit)
	.byte	0x01				# call-site format
						# DW_EH_PE_uleb128
	.uleb128 .Lcstend-.Lcstbegin
.Lcstbegin:
	.uleb128 .LcleanupSTART-.LSTARTCODE
	.uleb128 .LcleanupEND-.LcleanupSTART
	.uleb128 clear_once_control-.LSTARTCODE
	.uleb128  0
	.uleb128 .LcallUR-.LSTARTCODE
	.uleb128 .LENDCODE-.LcallUR
	.uleb128 0
	.uleb128  0
.Lcstend:


	.section .eh_frame,"a",@progbits
.LSTARTFRAME:
	.long	.LENDCIE-.LSTARTCIE		# Length of the CIE.
.LSTARTCIE:
	.long	0				# CIE ID.
	.byte	1				# Version number.
#ifdef SHARED
	.string	"zPLR"				# NUL-terminated augmentation
						# string.
#else
	.string	"zPL"				# NUL-terminated augmentation
						# string.
#endif
	.uleb128 1				# Code alignment factor.
	.sleb128 -8				# Data alignment factor.
	.byte	16				# Return address register
						# column.
#ifdef SHARED
	.uleb128 7				# Augmentation value length.
	.byte	0x9b				# Personality: DW_EH_PE_pcrel
						# + DW_EH_PE_sdata4
						# + DW_EH_PE_indirect
	.long	DW.ref.__gcc_personality_v0-.
	.byte	0x1b				# LSDA Encoding: DW_EH_PE_pcrel
						# + DW_EH_PE_sdata4.
	.byte	0x1b				# FDE Encoding: DW_EH_PE_pcrel
						# + DW_EH_PE_sdata4.
#else
	.uleb128 10				# Augmentation value length.
	.byte	0x0				# Personality: absolute
	.quad	__gcc_personality_v0
	.byte	0x0				# LSDA Encoding: absolute
#endif
	.byte 0x0c				# DW_CFA_def_cfa
	.uleb128 7
	.uleb128 8
	.byte	0x90				# DW_CFA_offset, column 0x10
	.uleb128 1
	.align 8
.LENDCIE:

	.long	.LENDFDE-.LSTARTFDE		# Length of the FDE.
.LSTARTFDE:
	.long	.LSTARTFDE-.LSTARTFRAME		# CIE pointer.
#ifdef SHARED
	.long	.LSTARTCODE-.			# PC-relative start address
						# of the code.
	.long	.LENDCODE-.LSTARTCODE		# Length of the code.
	.uleb128 4				# Augmentation size
	.long	.LexceptSTART-.
#else
	.quad	.LSTARTCODE			# Start address of the code.
	.quad	.LENDCODE-.LSTARTCODE		# Length of the code.
	.uleb128 8				# Augmentation size
	.quad	.LexceptSTART
#endif
	.byte	4				# DW_CFA_advance_loc4
	.long	.Lpush_rsi-.LSTARTCODE
	.byte	14				# DW_CFA_def_cfa_offset
	.uleb128 16
	.byte	4				# DW_CFA_advance_loc4
	.long	.Lpush_rdi-.Lpush_rsi
	.byte	14				# DW_CFA_def_cfa_offset
	.uleb128 24
	.byte	4				# DW_CFA_advance_loc4
	.long	.Lpop_rdi-.Lpush_rdi
	.byte	14				# DW_CFA_def_cfa_offset
	.uleb128 16
	.byte	4				# DW_CFA_advance_loc4
	.long	.Ladd-.Lpop_rdi
	.byte	14				# DW_CFA_def_cfa_offset
	.uleb128 8
	.byte	4				# DW_CFA_advance_loc4
	.long	clear_once_control-.Ladd
	.byte	14				# DW_CFA_def_cfa_offset
	.uleb128 24
#if 0
	.byte	4				# DW_CFA_advance_loc4
	.long	.Lpop_rdi2-clear_once_control
	.byte	14				# DW_CFA_def_cfa_offset
	.uleb128 16
#endif
	.align	8
.LENDFDE:


#ifdef SHARED
	.hidden	DW.ref.__gcc_personality_v0
	.weak	DW.ref.__gcc_personality_v0
	.section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits
	.align	8
	.type	DW.ref.__gcc_personality_v0, @object
	.size	DW.ref.__gcc_personality_v0, 8
DW.ref.__gcc_personality_v0:
	.quad	__gcc_personality_v0
#endif
Commit	Line	Data
a334319f	1	/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
654dff90 UD	2	This file is part of the GNU C Library.
	3	Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, write to the Free
	17	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	18	02111-1307 USA. */
	19
	20	#ifndef UP
	21	# define LOCK lock
	22	#else
	23	# define LOCK
	24	#endif
	25
	26	#define SYS_futex 202
	27	#define FUTEX_WAKE 1
	28
	29	.comm __fork_generation, 4, 4
	30
	31	.text
	32
	33
	34	.globl __pthread_once
	35	.type __pthread_once,@function
	36	.align 16
	37	__pthread_once:
3b985826	38	.LSTARTCODE:
654dff90 UD	39	testl $2, (%rdi)
	40	jz 1f
	41	xorl %eax, %eax
c2e5e085	42	retq
654dff90	43
c2e5e085 UD	44	/* Preserve the function pointer. */
c2e5e085 UD	45	1: pushq %rsi
3b985826	46	.Lpush_rsi:
c2e5e085	47	xorq %r10, %r10
654dff90 UD	48
	49	/* Not yet initialized or initialization in progress.
	50	Get the fork generation counter now. */
	51	6: movl (%rdi), %eax
	52
c2e5e085	53	5: movl %eax, %edx
654dff90 UD	54
654dff90 UD	55	testl $2, %eax
c2e5e085	56	jnz 4f
654dff90 UD	57
	58	andl $3, %edx
	59	orl __fork_generation(%rip), %edx
	60	orl $1, %edx
	61
	62	LOCK
	63	cmpxchgl %edx, (%rdi)
	64	jnz 5b
	65
	66	/* Check whether another thread already runs the initializer. */
	67	testl $1, %eax
	68	jz 3f /* No -> do it. */
	69
	70	/* Check whether the initializer execution was interrupted
	71	by a fork. */
	72	xorl %edx, %eax
	73	testl $0xfffffffc, %eax
	74	jnz 3f /* Different for generation -> run initializer. */
	75
	76	/* Somebody else got here first. Wait. */
a334319f UD	77	movq %r10, %rsi /* movq $FUTEX_WAIT, %rsi */
a334319f UD	78	movq $SYS_futex, %rax
654dff90 UD	79	syscall
	80	jmp 6b
	81
	82	/* Preserve the pointer to the control variable. */
	83	3: pushq %rdi
3b985826	84	.Lpush_rdi:
654dff90	85
3b985826	86	.LcleanupSTART:
a334319f	87	callq *8(%rsp)
3b985826	88	.LcleanupEND:
654dff90 UD	89
	90	/* Get the control variable address back. */
	91	popq %rdi
3b985826	92	.Lpop_rdi:
654dff90 UD	93
	94	/* Sucessful run of the initializer. Signal that we are done. */
	95	LOCK
	96	incl (%rdi)
	97
	98	/* Wake up all other threads. */
	99	movl $0x7fffffff, %edx
	100	movl $FUTEX_WAKE, %esi
a334319f	101	movq $SYS_futex, %rax
654dff90 UD	102	syscall
654dff90 UD	103
8b4a0b2f	104	4: addq $8, %rsp
a334319f UD	105	.Ladd:
a334319f UD	106	xorq %rax, %rax
c2e5e085	107	retq
654dff90 UD	108
	109	.size __pthread_once,.-__pthread_once
	110
7588880f UD	111
	112	.globl __pthread_once_internal
	113	__pthread_once_internal = __pthread_once
	114
654dff90 UD	115	.globl pthread_once
	116	pthread_once = __pthread_once
	117
	118
	119	.type clear_once_control,@function
	120	.align 16
	121	clear_once_control:
3b985826 UD	122	movq (%rsp), %rdi
3b985826 UD	123	movq %rax, %r8
654dff90 UD	124	movl $0, (%rdi)
654dff90 UD	125
654dff90	126	movl $0x7fffffff, %edx
a334319f UD	127	movq $FUTEX_WAKE, %rsi
a334319f UD	128	movq $SYS_futex, %rax
654dff90 UD	129	syscall
654dff90 UD	130
3b985826 UD	131	movq %r8, %rdi
	132	.LcallUR:
	133	call _Unwind_Resume@PLT
	134	hlt
	135	.LENDCODE:
654dff90	136	.size clear_once_control,.-clear_once_control
3b985826 UD	137
	138
	139	.section .gcc_except_table,"a",@progbits
	140	.LexceptSTART:
	141	.byte 0xff # @LPStart format (omit)
	142	.byte 0xff # @TType format (omit)
	143	.byte 0x01 # call-site format
	144	# DW_EH_PE_uleb128
	145	.uleb128 .Lcstend-.Lcstbegin
	146	.Lcstbegin:
	147	.uleb128 .LcleanupSTART-.LSTARTCODE
	148	.uleb128 .LcleanupEND-.LcleanupSTART
	149	.uleb128 clear_once_control-.LSTARTCODE
	150	.uleb128 0
	151	.uleb128 .LcallUR-.LSTARTCODE
	152	.uleb128 .LENDCODE-.LcallUR
	153	.uleb128 0
	154	.uleb128 0
	155	.Lcstend:
	156
	157
	158	.section .eh_frame,"a",@progbits
	159	.LSTARTFRAME:
	160	.long .LENDCIE-.LSTARTCIE # Length of the CIE.
	161	.LSTARTCIE:
	162	.long 0 # CIE ID.
	163	.byte 1 # Version number.
	164	#ifdef SHARED
	165	.string "zPLR" # NUL-terminated augmentation
	166	# string.
	167	#else
	168	.string "zPL" # NUL-terminated augmentation
	169	# string.
	170	#endif
	171	.uleb128 1 # Code alignment factor.
	172	.sleb128 -8 # Data alignment factor.
	173	.byte 16 # Return address register
	174	# column.
	175	#ifdef SHARED
	176	.uleb128 7 # Augmentation value length.
	177	.byte 0x9b # Personality: DW_EH_PE_pcrel
	178	# + DW_EH_PE_sdata4
	179	# + DW_EH_PE_indirect
	180	.long DW.ref.__gcc_personality_v0-.
	181	.byte 0x1b # LSDA Encoding: DW_EH_PE_pcrel
	182	# + DW_EH_PE_sdata4.
	183	.byte 0x1b # FDE Encoding: DW_EH_PE_pcrel
	184	# + DW_EH_PE_sdata4.
	185	#else
	186	.uleb128 10 # Augmentation value length.
	187	.byte 0x0 # Personality: absolute
	188	.quad __gcc_personality_v0
	189	.byte 0x0 # LSDA Encoding: absolute
	190	#endif
	191	.byte 0x0c # DW_CFA_def_cfa
	192	.uleb128 7
	193	.uleb128 8
	194	.byte 0x90 # DW_CFA_offset, column 0x10
	195	.uleb128 1
	196	.align 8
	197	.LENDCIE:
	198
	199	.long .LENDFDE-.LSTARTFDE # Length of the FDE.
	200	.LSTARTFDE:
201	.long .LSTARTFDE-.LSTARTFRAME # CIE pointer.
202	#ifdef SHARED
203	.long .LSTARTCODE-. # PC-relative start address
204	# of the code.
205	.long .LENDCODE-.LSTARTCODE # Length of the code.
206	.uleb128 4 # Augmentation size
207	.long .LexceptSTART-.
208	#else
209	.quad .LSTARTCODE # Start address of the code.
210	.quad .LENDCODE-.LSTARTCODE # Length of the code.
211	.uleb128 8 # Augmentation size
212	.quad .LexceptSTART
213	#endif
214	.byte 4 # DW_CFA_advance_loc4
215	.long .Lpush_rsi-.LSTARTCODE
216	.byte 14 # DW_CFA_def_cfa_offset
217	.uleb128 16
218	.byte 4 # DW_CFA_advance_loc4
219	.long .Lpush_rdi-.Lpush_rsi
220	.byte 14 # DW_CFA_def_cfa_offset
221	.uleb128 24
222	.byte 4 # DW_CFA_advance_loc4
a334319f	223	.long .Lpop_rdi-.Lpush_rdi
3b985826 UD	224	.byte 14 # DW_CFA_def_cfa_offset
	225	.uleb128 16
	226	.byte 4 # DW_CFA_advance_loc4
a334319f	227	.long .Ladd-.Lpop_rdi
3b985826 UD	228	.byte 14 # DW_CFA_def_cfa_offset
	229	.uleb128 8
	230	.byte 4 # DW_CFA_advance_loc4
a334319f	231	.long clear_once_control-.Ladd
3b985826	232	.byte 14 # DW_CFA_def_cfa_offset
a334319f	233	.uleb128 24
3b985826 UD	234	#if 0
3b985826 UD	235	.byte 4 # DW_CFA_advance_loc4
a334319f	236	.long .Lpop_rdi2-clear_once_control
3b985826 UD	237	.byte 14 # DW_CFA_def_cfa_offset
	238	.uleb128 16
	239	#endif
	240	.align 8
	241	.LENDFDE:
	242
	243
	244	#ifdef SHARED
	245	.hidden DW.ref.__gcc_personality_v0
	246	.weak DW.ref.__gcc_personality_v0
	247	.section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits
	248	.align 8
	249	.type DW.ref.__gcc_personality_v0, @object
	250	.size DW.ref.__gcc_personality_v0, 8
	251	DW.ref.__gcc_personality_v0:
	252	.quad __gcc_personality_v0
	253	#endif