glibc/sysdeps/unix/sysv/linux/alpha/makecontext.S

164 lines
3.7 KiB
ArmAsm

/* Copyright (C) 2004-2024 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-offsets.h>
ENTRY(__makecontext)
ldgp $29, 0($27)
#ifdef PROF
.set noat
lda AT, _mcount
jsr AT, (AT), _mcount
.set at
#endif
.prologue 1
/* Compute top of stack, including arguments. */
ldq $1, UC_STACK+SS_SP($16)
ldq $2, UC_STACK+SS_SIZE($16)
addq $1, $2, $8
subq $18, 6, $1
cmovlt $1, 0, $1
s8addq $1, 0, $2
subq $8, $2, $8
/* Copy all parameters. Switch statement header here. */
ldah $3, $jumptable($29) !gprelhigh
cmple $18, 6, $1
mov $18, $2
cmoveq $1, 7, $2
s4addq $2, $3, $3
ldl $4, $jumptable($3) !gprellow
addq $4, $29, $4
jmp $31, ($4), $args1
.section .rodata
.align 2
$jumptable:
.gprel32 $args0
.gprel32 $args1
.gprel32 $args2
.gprel32 $args3
.gprel32 $args4
.gprel32 $args5
.gprel32 $args6
.gprel32 $argsN
.text
/* Here we process arguments 7 through N. This is a straight
stack-to-stack copy. */
.align 4
$argsN:
subq $18, 6, $1
lda $2, 0($8)
lda $3, 3*8($30)
.align 4
1:
ldq $0, 0($3)
subq $1, 1, $1
lda $3, 8($3)
stq $0, 0($2)
lda $2, 8($2)
bne $1, 1b
/* Here we process arguments 6 through 0. This involves
copying into the register save areas of the ucontext. */
.align 4
$args6:
ldq $0, 2*8($30)
stq $0, UC_SIGCTX+SC_REGS+21*8($16)
unop
stq $0, UC_SIGCTX+SC_FPREGS+21*8($16)
$args5:
ldq $0, 1*8($30)
stq $0, UC_SIGCTX+SC_REGS+20*8($16)
unop
stq $0, UC_SIGCTX+SC_FPREGS+20*8($16)
$args4:
ldq $0, 0*8($30)
stq $0, UC_SIGCTX+SC_REGS+19*8($16)
unop
stq $0, UC_SIGCTX+SC_FPREGS+19*8($16)
$args3:
unop
stq $21, UC_SIGCTX+SC_REGS+18*8($16)
unop
stt $f21, UC_SIGCTX+SC_FPREGS+18*8($16)
$args2:
unop
stq $20, UC_SIGCTX+SC_REGS+17*8($16)
unop
stt $f20, UC_SIGCTX+SC_FPREGS+17*8($16)
$args1:
unop
stq $19, UC_SIGCTX+SC_REGS+16*8($16)
unop
stt $f19, UC_SIGCTX+SC_FPREGS+16*8($16)
$args0:
/* Set up the registers ready to invoke __startcontext.
We seed $27 with the target function address, and $9
with the link from ucp. */
ldah $0, __startcontext($29) !gprelhigh
ldq $1, UC_LINK($16)
lda $0, __startcontext($0) !gprellow
stq $17, UC_SIGCTX+SC_REGS+27*8($16)
stq $8, UC_SIGCTX+SC_REGS+30*8($16)
stq $0, UC_SIGCTX+SC_PC($16)
stq $1, UC_SIGCTX+SC_REGS+9*8($16)
/* No return value from makecontext. */
ret
END(__makecontext)
weak_alias (__makecontext, makecontext)
/* This function is where a new makecontext "thread" begins life.
We have already set up $27 for calling the target function, and
we've set $9 to the UC_LINK of the parent context.
If the function returns, we either jump to the linked context
(if non-null) or exit. */
.align 4
.ent __startcontext
__startcontext:
.frame $31, 0, $31, 0
.prologue 0
jsr $26, ($27), 0
ldgp $29, 0($26)
mov $9, $16
beq $9, 1f
#ifdef PIC
bsr $26, __setcontext !samegp
1: mov $31, $16
bsr $26, HIDDEN_JUMPTARGET(exit) !samegp
#else
jsr $26, __setcontext
ldgp $29, 0($26)
1: mov $31, $16
jsr $26, HIDDEN_JUMPTARGET(exit)
#endif
halt
.end __startcontext