131 lines
4.0 KiB
C
131 lines
4.0 KiB
C
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/**
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*
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* Varargs for PYR/GNU CC
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*
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* WARNING -- WARNING -- DANGER
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*
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* The code in this file implements varargs for gcc on a pyr in
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* a way that is compatible with code compiled by the Pyramid Technology
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* C compiler.
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* As such, it depends strongly on the Pyramid conventions for
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* parameter passing.ct and independent implementation.
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* These (somewhat bizarre) parameter-passing conventions are described
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* in the ``OSx Operating System Porting Guide''.
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*
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* A quick summary is useful:
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* 12 of the 48 register-windowed regs available for
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* parameter passing. Parameters of a function call that are eligible
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* to be passed in registers are assigned registers from TR0/PR0 onwards;
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* all other arguments are passed on the stack.
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* Structure and union parameters are *never* passed in registers,
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* even if they are small enough to fit. They are always passed on
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* the stack.
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*
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* Double-sized parameters cannot be passed in TR11, because
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* TR12 is not used for passing parameters. If, in the absence of this
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* rule, a double-sized param would have been passed in TR11,
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* that parameter is passed on the stack and no parameters are
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* passed in TR11.
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*
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* It is only known to work for passing 32-bit integer quantities
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* (ie chars, shorts, ints/enums, longs), doubles, or pointers.
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* Passing structures on a Pyramid via varargs is a loser.
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* Passing an object larger than 8 bytes on a pyramid via varargs may
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* also be a loser.
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*
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*/
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/*
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* pointer to next stack parameter in __va_buf[0]
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* pointer to next parameter register in __va_buf[1]
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* Count of registers seen at __va_buf[2]
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* saved pr0..pr11 in __va_buf[3..14]
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* # of calls to va_arg (debugging) at __va_buf[15]
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*/
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/* Define __gnuc_va_list. */
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#ifndef __GNUC_VA_LIST
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#define __GNUC_VA_LIST
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typedef void *__voidptr;
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#if 1
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typedef struct __va_regs {
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__voidptr __stackp,__regp,__count;
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__voidptr __pr0,__pr1,__pr2,__pr3,__pr4,__pr5,__pr6,__pr7,__pr8,__pr9,__pr10,__pr11;
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} __va_regs;
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typedef __va_regs __va_buf;
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#else
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/* __va_buf[0] = address of next arg passed on the stack
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__va_buf[1] = address of next arg passed in a register
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__va_buf[2] = register-# of next arg passed in a register
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*/
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typedef __voidptr(*__va_buf);
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#endif
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typedef __va_buf __gnuc_va_list;
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#endif /* not __GNUC_VA_LIST */
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/* If this is for internal libc use, don't define anything but
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__gnuc_va_list. */
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#if defined (_STDARG_H) || defined (_VARARGS_H)
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/* In GCC version 2, we want an ellipsis at the end of the declaration
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of the argument list. GCC version 1 can't parse it. */
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#if __GNUC__ > 1
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#define __va_ellipsis ...
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#else
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#define __va_ellipsis
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#endif
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#define va_alist \
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__va0,__va1,__va2,__va3,__va4,__va5,__va6,__va7,__va8,__va9,__va10,__va11, \
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__builtin_va_alist
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/* The ... causes current_function_varargs to be set in cc1. */
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#define va_dcl __voidptr va_alist; __va_ellipsis
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/* __asm ("rcsp %0" : "=r" ( _AP [0]));*/
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#define va_start(_AP) \
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_AP = ((struct __va_regs) { \
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&(_AP.__pr0), (void*)&__builtin_va_alist, (void*)0, \
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__va0,__va1,__va2,__va3,__va4,__va5, \
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__va6,__va7,__va8,__va9,__va10,__va11})
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/* Avoid errors if compiling GCC v2 with GCC v1. */
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#if __GNUC__ == 1
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#define __extension__
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#endif
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/* We cast to void * and then to TYPE * because this avoids
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a warning about increasing the alignment requirement. */
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#define va_arg(_AP, _MODE) \
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__extension__ \
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(*({__voidptr *__ap = (__voidptr*)&_AP; \
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register int __size = sizeof (_MODE); \
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register int __onstack = \
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(__size > 8 || ( (int)(__ap[2]) > 11) || \
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(__size==8 && (int)(__ap[2])==11)); \
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register int* __param_addr = ((int*)((__ap) [__onstack])); \
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\
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((void *)__ap[__onstack])+=__size; \
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if (__onstack==0 || (int)(__ap[2])==11) \
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__ap[2]+= (__size >> 2); \
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(( _MODE *) (void *) __param_addr); \
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}))
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void va_end (__gnuc_va_list); /* Defined in libgcc.a */
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#define va_end(_X) ((void)0)
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#endif /* defined (_STDARG_H) || defined (_VARARGS_H) */
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