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/* Save current context and install the given one.
Copyright (C) 2005-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include "ucontext_i.h"
/* int __swapcontext (ucontext_t *ouc, const ucontext_t *uc); */
.text
.align 5
ENTRY(__swapcontext)
/* Return value of getcontext. R0 is the only register whose
value is not preserved. */
mov #0, r0
mov.l r0, @(oR0,r4)
mov.l r1, @(oR1,r4)
mov.l r2, @(oR2,r4)
mov.l r3, @(oR3,r4)
mov.l r4, @(oR4,r4)
mov.l r5, @(oR5,r4)
mov.l r6, @(oR6,r4)
mov.l r7, @(oR7,r4)
mov r4, r0
add #(oMACL+4), r0
sts.l macl, @-r0
sts.l mach, @-r0
stc.l gbr, @-r0
/* Save T flag to SR. */
movt r1
mov.l r1, @-r0
sts.l pr, @-r0
/* The return address of getcontext is the restart pc. */
sts.l pr, @-r0
mov.l r15, @-r0
mov.l r14, @-r0
mov.l r13, @-r0
mov.l r12, @-r0
mov.l r11, @-r0
mov.l r10, @-r0
mov.l r9, @-r0
mov.l r8, @-r0
mov r5, r8
/* sigprocmask (SIG_SETMASK, &uc->uc_sigmask, &ouc->uc_sigmask). */
add #oSIGMASK, r5
mov r4, r6
add #oSIGMASK, r6
mov #SIG_SETMASK, r4
mov #+SYS_ify(sigprocmask), r3
trapa #0x13
mov r0, r1
mov #-12, r2
shad r2, r1
not r1, r1 // r1=0 means r0 = -1 to -4095
tst r1, r1 // i.e. error in linux
bf .Lswapcontext_restore
.Lsyscall_error:
SYSCALL_ERROR_HANDLER
.Lpseudo_end:
rts
nop
.Lswapcontext_restore:
mov r8, r0
add #(oPC), r0
mov.l @r0+, r2
lds.l @r0+, pr
/* Restore T frag. */
mov.l @r0+, r1
shlr r1
/* Skip GBR which is used for thread pointer. */
add #4, r0
lds.l @r0+, mach
lds.l @r0+, macl
mov r8, r0
add #(oR9), r0
mov.l @r0+, r9
mov.l @r0+, r10
mov.l @r0+, r11
mov.l @r0+, r12
mov.l @r0+, r13
mov.l @r0+, r14
mov.l @r0+, r15
mov r8, r0
mov.l @(oR0,r0), r1
mov.l r1, @-r15
cfi_adjust_cfa_offset(4)
cfi_rel_offset (r1, 0)
mov.l r2, @-r15
cfi_adjust_cfa_offset(4)
cfi_rel_offset (r2, 0)
mov.l @(oR1,r0), r1
mov.l @(oR2,r0), r2
mov.l @(oR3,r0), r3
mov.l @(oR4,r0), r4
mov.l @(oR5,r0), r5
mov.l @(oR6,r0), r6
mov.l @(oR7,r0), r7
mov.l @(oR8,r0), r8
mov.l @r15+, r0
cfi_adjust_cfa_offset(-4)
jmp @r0
mov.l @r15+, r0
PSEUDO_END(__swapcontext)
weak_alias (__swapcontext, swapcontext)
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