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/*
* Mach Operating System
* Copyright (c) 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
#ifndef _I386_FPU_H_
#define _I386_FPU_H_
/*
* Macro definitions for routines to manipulate the
* floating-point processor.
*/
#include <i386/proc_reg.h>
#include <i386/thread.h>
/*
* FPU instructions.
*/
#define fninit() \
asm volatile("fninit")
#define fnstcw(control) \
asm("fnstcw %0" : "=m" (*(unsigned short *)(control)))
#define fstcw(control) \
asm volatile("fstcw %0" : "=m" (*(unsigned short *)(control)))
#define fldcw(control) \
asm volatile("fldcw %0" : : "m" (*(unsigned short *) &(control)) )
#define fnstsw() \
({ \
unsigned short _status__; \
asm("fnstsw %0" : "=ma" (_status__)); \
_status__; \
})
#define fnclex() \
asm volatile("fnclex")
#define fnsave(state) \
asm volatile("fnsave %0" : "=m" (*state))
#define frstor(state) \
asm volatile("frstor %0" : : "m" (state))
#define fwait() \
asm("fwait");
/*
* If floating-point instructions are emulated,
* we must load the floating-point register selector
* when switching to a new thread.
*/
#if FPE
extern void disable_fpe();
extern void enable_fpe();
#define fpu_save_context(thread) \
{ \
if (fp_kind == FP_SOFT) \
disable_fpe(); \
else \
set_ts(); \
}
#define fpu_load_context(pcb) \
{ \
register struct i386_fpsave_state *ifps; \
if (fp_kind == FP_SOFT && (ifps = pcb->ims.ifps) != 0) \
enable_fpe(ifps); \
}
#else /* no FPE */
#define fpu_load_context(pcb)
/*
* Save thread`s FPU context.
* If only one CPU, we just set the task-switched bit,
* to keep the new thread from using the coprocessor.
* If multiple CPUs, we save the entire state.
*/
#if NCPUS > 1
#define fpu_save_context(thread) \
{ \
register struct i386_fpsave_state *ifps; \
ifps = (thread)->pcb->ims.ifps; \
if (ifps != 0 && !ifps->fp_valid) { \
/* registers are in FPU - save to memory */ \
ifps->fp_valid = TRUE; \
fnsave(&ifps->fp_save_state); \
set_ts(); \
} \
}
#else /* NCPUS == 1 */
#define fpu_save_context(thread) \
{ \
set_ts(); \
}
#endif /* NCPUS == 1 */
#endif /* no FPE */
extern int fp_kind;
#endif /* _I386_FPU_H_ */
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