src/cpu_dep.c

   1 /*
   2 Copyright (C) 2001-2003, The Perl Foundation.
   3 $Id$
   4
   5 =head1 NAME
   6
   7 src/cpu_dep.c - CPU-dependent functions
   8
   9 =head1 DESCRIPTION
  10
  11 These functions are called while stackwalking during dead object
  12 destruction. They implement conditional CPU-specific behaviour related
  13 to register windowing.
  14
  15 Register windowing is a technique which avoids having to empty registers
  16 by moving a virtual window up/down the register stack restricting the
  17 number of registers which are visible.
  18
  19 Remember you read something about it in F<docs/infant.dev>?
  20
  21 =head2 Functions
  22
  23 =over 4
  24
  25 =cut
  26
  27 */
  28
  29 #include "parrot/parrot.h"
  30
  31 #ifdef __ia64__
  32
  33 #  include <ucontext.h>
  34 extern void *flush_reg_store(void);
  35 #  define BACKING_STORE_BASE 0x80000fff80000000
  36
  37 #endif
  38
  39 static void trace_system_stack(Interp *interp);
  40
  41 /*
  42
  43 =item C<void trace_system_areas(Interp *interp)>
  44
  45 Traces the system stack and any additional CPU-specific areas.
  46
  47 =cut
  48
  49 */
  50
  51 void
  52 trace_system_areas(Interp *interp)
  53 {
  54 #if defined(__sparc) /* Flush register windows */
  55     static union {
  56         unsigned int insns[4];
  57         double align_hack[2];
  58     } u = { {
  59 #  ifdef __sparcv9
  60                             0x81580000, /* flushw */
  61 #  else
  62                             0x91d02003, /* ta ST_FLUSH_WINDOWS */
  63 #  endif
  64                             0x81c3e008, /* retl */
  65                             0x01000000  /* nop */
  66     } };
  67
  68     static void (*fn_ptr)(void) = (void (*)(void))&u.align_hack[0];
  69     fn_ptr();
  70
  71 #elif defined(__ia64__)
  72
  73     struct ucontext ucp;
  74     void *current_regstore_top;
  75
  76     getcontext(&ucp);
  77     current_regstore_top = flush_reg_store();
  78
  79     trace_mem_block(interp, 0x80000fff80000000,
  80             (size_t)current_regstore_top);
  81 #else
  82
  83 #  ifdef PARROT_HAS_HEADER_SETJMP
  84     Parrot_jump_buff env;
  85
  86     /* Zero the Parrot_jump_buff, otherwise you will trace stale objects */
  87     memset(&env, 0, sizeof (env));
  88
  89     /* this should put registers in env, which then get marked in
  90      * trace_system_stack below
  91      */
  92     setjmp(env);
  93 #  endif
  94
  95 #endif
  96
  97
  98     trace_system_stack(interp);
  99 }
 100
 101 /*
 102
 103 =item C<static void
 104 trace_system_stack(Interp *interp)>
 105
 106 Traces the memory block starting at C<< interp->lo_var_ptr >>.
 107
 108 =cut
 109
 110 */
 111
 112 static void
 113 trace_system_stack(Interp *interp)
 114 {
 115     size_t lo_var_ptr = (size_t)interp->lo_var_ptr;
 116
 117     trace_mem_block(interp, (size_t)lo_var_ptr,
 118             (size_t)&lo_var_ptr);
 119 }
 120
 121 /*
 122
 123 =back
 124
 125 =head1 SEE ALSO
 126
 127 F<src/dod.c>, F<include/parrot/dod.h> and F<docs/infant.dev>.
 128
 129 =cut
 130
 131 */
 132
 133
 134 /*
 135  * Local variables:
 136  *   c-file-style: "parrot"
 137  * End:
 138  * vim: expandtab shiftwidth=4:
 139  */