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MFi386: revision 190919

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Simplify in/out functions.

  Remove a hack to generate more efficient code for port numbers below
  0x100, which has been obsolete for at least ten years, because GCC has
  an asm constraint to specify that.
This commit is contained in:
Yoshihiro Takahashi 2009-04-11 14:25:47 +00:00
parent 20f96000fa
commit e532d3fafa
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=190928
1 changed files with 8 additions and 29 deletions
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37
sys/pc98/pc98/machdep.c
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@ -2791,45 +2791,24 @@ user_dbreg_trap(void)
#ifdef KDB
/*
* Provide inb() and outb() as functions. They are normally only
* available as macros calling inlined functions, thus cannot be
* called from the debugger.
*
* The actual code is stolen from <machine/cpufunc.h>, and de-inlined.
* Provide inb() and outb() as functions. They are normally only available as
* inline functions, thus cannot be called from the debugger.
*/
#undef inb
#undef outb
/* silence compiler warnings */
u_char inb(u_int);
void outb(u_int, u_char);
u_char inb_(u_short);
void outb_(u_short, u_char);
u_char
inb(u_int port)
inb_(u_short port)
{
u_char data;
/*
* We use %%dx and not %1 here because i/o is done at %dx and not at
* %edx, while gcc generates inferior code (movw instead of movl)
* if we tell it to load (u_short) port.
*/
__asm __volatile("inb %%dx,%0" : "=a" (data) : "d" (port));
return (data);
return inb(port);
}
void
outb(u_int port, u_char data)
outb_(u_short port, u_char data)
{
u_char al;
/*
* Use an unnecessary assignment to help gcc's register allocator.
* This make a large difference for gcc-1.40 and a tiny difference
* for gcc-2.6.0. For gcc-1.40, al had to be ``asm("ax")'' for
* best results. gcc-2.6.0 can't handle this.
*/
al = data;
__asm __volatile("outb %0,%%dx" : : "a" (al), "d" (port));
outb(port, data);
}
#endif /* KDB */