glibc/sysdeps/unix/sysv/linux/ia64/__start_context.S
2014-02-16 01:12:38 -05:00

52 lines
1.6 KiB
ArmAsm

/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by David Mosberger-Tang <davidm@hpl.hp.com>.
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
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <features.h>
/* When a context set up by __makecontext() is activated, control
transfers to __start_context. When we get here:
b1 = entry point of function to call
in0 = address of UCP to resume after function returns
in1 = global pointer for __start_context
out0 .. outN = arguments for function */
ENTRY(__start_context)
.prologue
alloc r2 = ar.pfs, 2, 0, 8, 0
.save rp, r4 // terminate call chain with a NULL rp
mov r4 = r0
;;
.body
br.call.sptk rp = b1
1:
mov gp = in1 // restore gp
cmp.ne p6,p0 = in0, r0 // uc_link != 0 ?
;;
(p6) mov out0 = in0
(p6) br.call.sptk rp = __setcontext
.Lexit:
mov out0 = 0
br.call.sptk rp = HIDDEN_JUMPTARGET(exit)
1: br.cond.sptk .Lexit
END(__start_context)