gcc/ginclude/va-pyr.h

   1 /**
   2  *
   3  *      Varargs for PYR/GNU CC
   4  *
   5  * WARNING -- WARNING -- DANGER
   6  *
   7  * The code in this file implements varargs for gcc on a pyr in
   8  * a way that is compatible with code compiled by the Pyramid Technology
   9  * C compiler.
  10  * As such, it depends strongly on the Pyramid conventions for
  11  * parameter passing.ct and independent implementation.
  12  * These (somewhat bizarre) parameter-passing conventions are described
  13  * in the ``OSx Operating System Porting Guide''.
  14  *
  15  * A quick summary is useful:
  16  * 12 of the 48 register-windowed regs available for
  17  * parameter passing.  Parameters of a function call that are eligible
  18  * to be passed in registers are assigned registers from TR0/PR0 onwards;
  19  * all other arguments are passed on the stack.
  20  * Structure and union parameters are *never* passed in registers,
  21  * even if they are small enough to fit.  They are always passed on
  22  * the stack.
  23  *
  24  * Double-sized parameters cannot be passed in TR11, because
  25  * TR12 is not used for passing parameters.  If, in the absence of this
  26  * rule, a double-sized param would have been passed in TR11,
  27  * that parameter is passed on the stack and no parameters are
  28  * passed in TR11.
  29  *
  30  * It is only known to work for passing 32-bit integer quantities
  31  * (ie chars, shorts, ints/enums, longs), doubles, or pointers.
  32  * Passing structures on a Pyramid via varargs is a loser.
  33  * Passing an object larger than 8 bytes on a pyramid via varargs may
  34  * also be a loser.
  35  *
  36  */
  37
  38 \f
  39 /*
  40  *  pointer to next stack parameter in __va_buf[0]
  41  *  pointer to next parameter register in __va_buf[1]
  42  *  Count of registers seen at __va_buf[2]
  43  *  saved pr0..pr11 in __va_buf[3..14]
  44  *  # of calls to va_arg (debugging) at __va_buf[15]
  45  */
  46
  47 /* Define __gnuc_va_list.  */
  48
  49 #ifndef __GNUC_VA_LIST
  50 #define __GNUC_VA_LIST
  51
  52 typedef void *__voidptr;
  53 #if 1
  54
  55 typedef struct __va_regs {
  56       __voidptr __stackp,__regp,__count;
  57       __voidptr __pr0,__pr1,__pr2,__pr3,__pr4,__pr5,__pr6,__pr7,__pr8,__pr9,__pr10,__pr11;
  58   } __va_regs;
  59
  60 typedef __va_regs __va_buf;
  61 #else
  62
  63 /* __va_buf[0] = address of next arg passed on the stack
  64    __va_buf[1] = address of next arg passed in a register
  65    __va_buf[2] = register-# of next arg passed in a register
  66  */
  67 typedef __voidptr(*__va_buf);
  68
  69 #endif
  70
  71 typedef __va_buf __gnuc_va_list;
  72
  73 #endif /* not __GNUC_VA_LIST */
  74 \f
  75 /* If this is for internal libc use, don't define anything but
  76    __gnuc_va_list.  */
  77 #if defined (_STDARG_H) || defined (_VARARGS_H)
  78
  79 /* In GCC version 2, we want an ellipsis at the end of the declaration
  80    of the argument list.  GCC version 1 can't parse it.  */
  81
  82 #if __GNUC__ > 1
  83 #define __va_ellipsis ...
  84 #else
  85 #define __va_ellipsis
  86 #endif
  87
  88 #define va_alist \
  89   __va0,__va1,__va2,__va3,__va4,__va5,__va6,__va7,__va8,__va9,__va10,__va11, \
  90  __builtin_va_alist
  91
  92 /* The ... causes current_function_varargs to be set in cc1.  */
  93 #define va_dcl __voidptr va_alist; __va_ellipsis
  94
  95
  96 /* __asm ("rcsp %0" : "=r" ( _AP [0]));*/
  97
  98 #define va_start(_AP)  \
  99   _AP =  ((struct __va_regs) {                                          \
 100    &(_AP.__pr0), (void*)&__builtin_va_alist, (void*)0,                  \
 101         __va0,__va1,__va2,__va3,__va4,__va5,                            \
 102         __va6,__va7,__va8,__va9,__va10,__va11})
 103
 104
 105 /* Avoid errors if compiling GCC v2 with GCC v1.  */
 106 #if __GNUC__ == 1
 107 #define __extension__
 108 #endif
 109
 110 /* We cast to void * and then to TYPE * because this avoids
 111    a warning about increasing the alignment requirement.  */
 112 #define va_arg(_AP, _MODE)      \
 113 __extension__                                                           \
 114 (*({__voidptr *__ap = (__voidptr*)&_AP;                                 \
 115   register int __size = sizeof (_MODE);                                 \
 116   register int __onstack =                                              \
 117           (__size > 8 || ( (int)(__ap[2]) > 11) ||                      \
 118             (__size==8 && (int)(__ap[2])==11));                         \
 119   register int* __param_addr =  ((int*)((__ap) [__onstack]));           \
 120                                                                         \
 121   ((void *)__ap[__onstack])+=__size;                                    \
 122     if (__onstack==0 || (int)(__ap[2])==11)                             \
 123       __ap[2]+= (__size >> 2);                                          \
 124   (( _MODE *) (void *) __param_addr);                                   \
 125 }))
 126
 127 void va_end (__gnuc_va_list);           /* Defined in libgcc.a */
 128 #define va_end(_X)      ((void)0)
 129
 130 #endif /* defined (_STDARG_H) || defined (_VARARGS_H) */