codekingpro/portable-devtools

1/*
2 * this is the internal transfer function.
3 *
4 * HISTORY
5 * 16-May-15  Alexey Borzenkov <snaury@gmail.com>
6 *      Move stack spilling code inside save/restore functions
7 * 30-Aug-13  Floris Bruynooghe <flub@devork.be>
8        Clean the register windows again before returning.
9        This does not clobber the PIC register as it leaves
10        the current window intact and is required for multi-
11        threaded code to work correctly.
12 * 08-Mar-11  Floris Bruynooghe <flub@devork.be>
13 *      No need to set return value register explicitly
14 *      before the stack and framepointer are adjusted
15 *      as none of the other registers are influenced by
16 *      this.  Also don't needlessly clean the windows
17 *      ('ta %0" :: "i" (ST_CLEAN_WINDOWS)') as that
18 *      clobbers the gcc PIC register (%l7).
19 * 24-Nov-02  Christian Tismer  <tismer@tismer.com>
20 *      needed to add another magic constant to insure
21 *      that f in slp_eval_frame(PyFrameObject *f)
22 *      STACK_REFPLUS will probably be 1 in most cases.
23 *      gets included into the saved stack area.
24 * 17-Sep-02  Christian Tismer  <tismer@tismer.com>
25 *      after virtualizing stack save/restore, the
26 *      stack size shrunk a bit. Needed to introduce
27 *      an adjustment STACK_MAGIC per platform.
28 * 15-Sep-02  Gerd Woetzel       <gerd.woetzel@GMD.DE>
29 *      added support for SunOS sparc with gcc
30 */
31
32#define STACK_REFPLUS 1
33
34#ifdef SLP_EVAL
35
36
37#define STACK_MAGIC 0
38
39
40#if defined(__sparcv9)
41#define SLP_FLUSHW __asm__ volatile ("flushw")
42#else
43#define SLP_FLUSHW __asm__ volatile ("ta 3") /* ST_FLUSH_WINDOWS */
44#endif
45
46/* On sparc we need to spill register windows inside save/restore functions */
47#define SLP_BEFORE_SAVE_STATE() SLP_FLUSHW
48#define SLP_BEFORE_RESTORE_STATE() SLP_FLUSHW
49
50
51static int
52slp_switch(void)
53{
54    int err;
55    int *stackref, stsizediff;
56
57    /* Put current stack pointer into stackref.
58     * Register spilling is done in save/restore.
59     */
60    __asm__ volatile ("mov %%sp, %0" : "=r" (stackref));
61
62    {
63        /* Thou shalt put SLP_SAVE_STATE into a local block */
64        /* Copy the current stack onto the heap */
65        SLP_SAVE_STATE(stackref, stsizediff);
66
67        /* Increment stack and frame pointer by stsizediff */
68        __asm__ volatile (
69            "add %0, %%sp, %%sp\n\t"
70            "add %0, %%fp, %%fp"
71            : : "r" (stsizediff));
72
73        /* Copy new stack from it's save store on the heap */
74        SLP_RESTORE_STATE();
75
76        __asm__ volatile ("mov %1, %0" : "=r" (err) : "i" (0));
77        return err;
78    }
79}
80
81#endif
82
83/*
84 * further self-processing support
85 */
86
87/*
88 * if you want to add self-inspection tools, place them
89 * here. See the x86_msvc for the necessary defines.
90 * These features are highly experimental und not
91 * essential yet.
92 */
93