codekingpro/portable-devtools

1/*
2 * this is the internal transfer function.
3 *
4 * HISTORY
5 * 3-May-13   Ralf Schmitt  <ralf@systemexit.de>
6 *     Add support for strange GCC caller-save decisions
7 *     (ported from switch_aarch64_gcc.h)
8 * 18-Aug-11  Alexey Borzenkov  <snaury@gmail.com>
9 *      Correctly save rbp, csr and cw
10 * 01-Apr-04  Hye-Shik Chang    <perky@FreeBSD.org>
11 *      Ported from i386 to amd64.
12 * 24-Nov-02  Christian Tismer  <tismer@tismer.com>
13 *      needed to add another magic constant to insure
14 *      that f in slp_eval_frame(PyFrameObject *f)
15 *      STACK_REFPLUS will probably be 1 in most cases.
16 *      gets included into the saved stack area.
17 * 17-Sep-02  Christian Tismer  <tismer@tismer.com>
18 *      after virtualizing stack save/restore, the
19 *      stack size shrunk a bit. Needed to introduce
20 *      an adjustment STACK_MAGIC per platform.
21 * 15-Sep-02  Gerd Woetzel       <gerd.woetzel@GMD.DE>
22 *      slightly changed framework for spark
23 * 31-Avr-02  Armin Rigo         <arigo@ulb.ac.be>
24 *      Added ebx, esi and edi register-saves.
25 * 01-Mar-02  Samual M. Rushing  <rushing@ironport.com>
26 *      Ported from i386.
27 */
28
29#define STACK_REFPLUS 1
30
31#ifdef SLP_EVAL
32
33/* #define STACK_MAGIC 3 */
34/* the above works fine with gcc 2.96, but 2.95.3 wants this */
35#define STACK_MAGIC 0
36
37#define REGS_TO_SAVE "r12", "r13", "r14", "r15"
38
39static int
40slp_switch(void)
41{
42    int err;
43    void* rbp;
44    void* rbx;
45    unsigned int csr;
46    unsigned short cw;
47    /* This used to be declared 'register', but that does nothing in
48    modern compilers and is explicitly forbidden in some new
49    standards. */
50    long *stackref, stsizediff;
51    __asm__ volatile ("" : : : REGS_TO_SAVE);
52    __asm__ volatile ("fstcw %0" : "=m" (cw));
53    __asm__ volatile ("stmxcsr %0" : "=m" (csr));
54    __asm__ volatile ("movq %%rbp, %0" : "=m" (rbp));
55    __asm__ volatile ("movq %%rbx, %0" : "=m" (rbx));
56    __asm__ ("movq %%rsp, %0" : "=g" (stackref));
57    {
58        SLP_SAVE_STATE(stackref, stsizediff);
59        __asm__ volatile (
60            "addq %0, %%rsp\n"
61            "addq %0, %%rbp\n"
62            :
63            : "r" (stsizediff)
64            );
65        SLP_RESTORE_STATE();
66        __asm__ volatile ("xorq %%rax, %%rax" : "=a" (err));
67    }
68    __asm__ volatile ("movq %0, %%rbx" : : "m" (rbx));
69    __asm__ volatile ("movq %0, %%rbp" : : "m" (rbp));
70    __asm__ volatile ("ldmxcsr %0" : : "m" (csr));
71    __asm__ volatile ("fldcw %0" : : "m" (cw));
72    __asm__ volatile ("" : : : REGS_TO_SAVE);
73    return err;
74}
75
76#endif
77
78/*
79 * further self-processing support
80 */
81
82/*
83 * if you want to add self-inspection tools, place them
84 * here. See the x86_msvc for the necessary defines.
85 * These features are highly experimental und not
86 * essential yet.
87 */
88