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128 lines
1.9 KiB
128 lines
1.9 KiB
/***
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*fpctrl.c - fp low level control and status routines
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*
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* Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
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*
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*Purpose:
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* IEEE control and status routines for internal use.
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* These routines use machine specific constants while _controlfp,
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* _statusfp, and _clearfp use an abstracted control/status word
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*
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*Revision History:
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*
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* 03-31-92 GDP written
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* 05-12-92 GJF Rewrote fdivr as fdivrp st(1),st to work around C8-32
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* assertions.
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*
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*/
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#include <trans.h>
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extern uintptr_t _get_fpsr(void);
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extern void _set_fpsr(uintptr_t);
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extern void _fclrf(void);
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/*** _statfp
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*() -
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*
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*Purpose:
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* return user status word
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*
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*Entry:
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*
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*Exit:
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*
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*Exceptions:
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*
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*******************************************************************************/
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uintptr_t _statfp()
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{
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unsigned __int64 status;
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status = _get_fpsr();
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return status;
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}
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/*** _clrfp
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*() -
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*
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*Purpose:
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* return user status word and clear status
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*
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*Entry:
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*
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*Exit:
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*
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*Exceptions:
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*
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*******************************************************************************/
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uintptr_t _clrfp()
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{
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uintptr_t status;
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status = _get_fpsr();
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_fclrf();
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return status;
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}
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/*** _ctrlfp
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*() -
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*
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*Purpose:
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* return and set user control word
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*
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*Entry:
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*
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*Exit:
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*
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*Exceptions:
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*
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*******************************************************************************/
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uintptr_t _ctrlfp(uintptr_t newctrl, uintptr_t _mask)
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{
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uintptr_t oldCw;
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uintptr_t newCw;
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oldCw = _get_fpsr();
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newCw = (uintptr_t) ((newctrl & _mask) | (oldCw & ~_mask));
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newCw |= (oldCw & ~(unsigned __int64)0x0001f3f);
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_set_fpsr(newCw);
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return oldCw;
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}
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/*** _set_statfp
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*() -
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*
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*Purpose:
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* force selected exception flags to 1
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*
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*Entry:
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*
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*Exit:
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*
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*Exceptions:
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*
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*******************************************************************************/
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void _set_statfp(uintptr_t sw)
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{
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unsigned __int64 status;
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status = _get_fpsr();
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status |= sw;
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_set_fpsr(status);
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}
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