source: libcfa/src/concurrency/CtxSwitch-i386.S @ c7a900a

arm-ehjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-expr
Last change on this file since c7a900a was c7a900a, checked in by Thierry Delisle <tdelisle@…>, 22 months ago

More renames and clean-ups

  • Property mode set to 100644
File size: 2.4 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// CtxSwitch-i386.S --
8//
9// Author           : Thierry Delisle
10// Created On       : Tue Dec 6 12:27:26 2016
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Fri Jul 21 22:29:25 2017
13// Update Count     : 1
14//
15// This  library is free  software; you  can redistribute  it and/or  modify it
16// under the terms of the GNU Lesser General Public License as published by the
17// Free Software  Foundation; either  version 2.1 of  the License, or  (at your
18// option) any later version.
19//
20// This library is distributed in the  hope that it will be useful, but WITHOUT
21// ANY  WARRANTY;  without even  the  implied  warranty  of MERCHANTABILITY  or
22// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
23// for more details.
24//
25// You should  have received a  copy of the  GNU Lesser General  Public License
26// along  with this library.
27//
28
29// This context switch routine depends on the fact that the stack of a new
30// thread has been set up to look like the thread has saved its context in
31// the normal manner.
32//
33// void CtxSwitch( machine_context *from, machine_context *to );
34
35// Offsets in the context structure. This needs to be synchronized with the
36// high level code a little better.
37
38#define PTR_BYTE        4
39#define SP_OFFSET       ( 0 * PTR_BYTE )
40#define FP_OFFSET       ( 1 * PTR_BYTE )
41#define PC_OFFSET       ( 2 * PTR_BYTE )
42
43        .text
44        .align 2
45        .globl __cfactx_switch
46        .type  __cfactx_switch, @function
47__cfactx_switch:
48
49        // Copy the "from" context argument from the stack to register eax
50        // Return address is at 0(%esp), with parameters following
51
52        movl 4(%esp),%eax
53
54        // Save volatile registers on the stack.
55
56        pushl %ebx
57        pushl %edi
58        pushl %esi
59
60        // Save old context in the "from" area.
61
62        movl %esp,SP_OFFSET(%eax)
63        movl %ebp,FP_OFFSET(%eax)
64
65        // Copy the "to" context argument from the stack to register eax
66        // Having pushed three words (= 12 bytes) on the stack, the
67        // argument is now at 8 + 12 = 20(%esp)
68
69        movl 20(%esp),%eax
70
71        // Load new context from the "to" area.
72
73        movl SP_OFFSET(%eax),%esp
74        movl FP_OFFSET(%eax),%ebp
75
76        // Load volatile registers from the stack.
77
78        popl %esi
79        popl %edi
80        popl %ebx
81
82        // Return to thread.
83
84        ret
85        .size  __cfactx_switch, .-__cfactx_switch
86
87// Local Variables: //
88// mode: c //
89// tab-width: 4 //
90// End: //
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