From: "A.Appleyard" <A DOT APPLEYARD AT fs2 DOT mt DOT umist DOT ac DOT uk>
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Date: Tue, 15 Aug 1995 08:34:05 BST
Subject: Re: inline asm?

  othe AT df DOT lth DOT se (Ola Theander) wrote:-
> I like to know if it's possible to include asm code in the C source code
> using djgpp.

  Here is a Gnu C(++) example:-
long _ax,_bx,_cx,_dx,_si,_di,_bp,_es; short _flags;
/* These swop the registers with the (values currently in _ax etc) */
#define __SR() /* save the registers */           ({asm("xchgl %eax,__ax"); \
    asm("xchgl %ebx,__bx"); asm("xchgl %ecx,__cx"); asm("xchgl %edx,__dx"); \
    asm("xchgl %esi,__si"); asm("xchgl %edi,__di"); asm("xchgl %ebp,__bp"); })
#define __RR() /* restore the registers */      ({ \
    asm("pushf"); asm("popw __flags"); __SR();})
#define SEL _go32_info_block.selector_for_linear_memory
inline void _farpokeb(uns short selector, uns long offset, uns char value) {
  asm("movw %0,%%fs" : : "r" (selector));
  asm(".byte 0x64\n" " movb %0,(%1)" : : "r" ((uns char)value), "r" (offset));}
inline void _farpokew(uns short selector, uns long offset, uns short value) {
  asm("movw %0,%%fs" : : "r" (selector));
  asm(".byte 0x64\n" " movw %0,(%1)" : : "r" (value), "r" (offset));}
inline void _farpokel(uns short selector, uns long offset, uns long value) {
  asm("movw %0,%%fs" : : "r" (selector));
  asm(".byte 0x64\n" " movl %0,(%1)" : : "r" (value), "r" (offset));}
inline uns char _farpeekb(uns short selector, uns long offset) {uns char R;
  asm("movw %0,%%fs" : : "r" (selector));
  asm(".byte 0x64\n" " movb (%1),%0" : "=r" ((int)R) : "r" (offset)); return R;}
inline uns short _farpeekw(uns short selector, uns long offset) {uns short R;
  asm("movw %0,%%fs" : : "r" (selector));
  asm(".byte 0x64\n" " movw (%1),%0" : "=r" (R) : "r" (offset)); return R;}
inline uns long _farpeekl(uns short selector, uns long offset) {uns long R;
  asm("movw %0,%%fs" : : "r" (selector));
  asm(".byte 0x64\n" " movl (%1),%0" : "=r" (R) : "r" (offset)); return R;}