source: libcfa/src/concurrency/CtxSwitch-i386.S @ bf71cfd

aaron-thesisarm-ehcleanup-dtorsdeferred_resndemanglerjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprno_listpersistent-indexer
Last change on this file since bf71cfd was bf71cfd, checked in by Thierry Delisle <tdelisle@…>, 3 years ago

Moved up many directories in source

  • Property mode set to 100644
File size: 2.7 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  CtxSwitch
46CtxSwitch:
47
48        // Copy the "from" context argument from the stack to register eax
49        // Return address is at 0(%esp), with parameters following
50
51        movl 4(%esp),%eax
52
53        // Save floating & SSE control words on the stack.
54
55        sub    $8,%esp
56        stmxcsr 0(%esp)         // 4 bytes
57        fnstcw  4(%esp)         // 2 bytes
58
59        // Save volatile registers on the stack.
60
61        pushl %ebx
62        pushl %edi
63        pushl %esi
64
65        // Save old context in the "from" area.
66
67        movl %esp,SP_OFFSET(%eax)
68        movl %ebp,FP_OFFSET(%eax)
69//      movl 4(%ebp),%ebx       // save previous eip for debugger
70//      movl %ebx,PC_OFFSET(%eax)
71
72        // Copy the "to" context argument from the stack to register eax
73        // Having pushed three words (= 12 bytes) on the stack, the
74        // argument is now at 8 + 12 = 20(%esp)
75
76        movl 28(%esp),%eax
77
78        // Load new context from the "to" area.
79
80        movl SP_OFFSET(%eax),%esp
81        movl FP_OFFSET(%eax),%ebp
82
83        // Load volatile registers from the stack.
84
85        popl %esi
86        popl %edi
87        popl %ebx
88
89        // Load floating & SSE control words from the stack.
90
91        fldcw   4(%esp)
92        ldmxcsr 0(%esp)
93        add    $8,%esp
94
95        // Return to thread.
96
97        ret
98
99// Local Variables: //
100// mode: c //
101// tab-width: 4 //
102// End: //
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