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385 lines
6.5 KiB
385 lines
6.5 KiB
/***
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*ieee.c - ieee 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.
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*
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*Revision History:
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*
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* 04-01-02 GDP Rewritten to use abstract control and status words
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* 06-06-01 GB Added _DN_FLUSH
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*
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*/
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#ifndef _IA64_
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#define _IA64_
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#endif
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#include <trans.h>
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#include <float.h>
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#include <nt.h>
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#include <signal.h>
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extern unsigned __int64 _get_fpsr(void);
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extern void _set_fpsr(unsigned __int64);
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extern void _fclrf(void);
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static unsigned int _abstract_sw(unsigned __int64 sw);
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static unsigned int _abstract_cw(unsigned __int64 cw);
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static unsigned __int64 _hw_cw(unsigned int abstr);
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#define FS (1<<6)
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#define CWMASK 0x00001f7f
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#define FTZ 0x00000040
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/***
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* _statusfp() -
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*
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*Purpose:
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* return abstract fp 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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unsigned int _statusfp()
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{
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unsigned __int64 status;
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status = _get_fpsr();
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return _abstract_sw(status);
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}
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/***
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*_clearfp() -
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*
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*Purpose:
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* return abstract 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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unsigned int _clearfp()
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{
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unsigned __int64 status;
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status = _get_fpsr();
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_fclrf();
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return _abstract_sw(status);
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}
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/*** _control87
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*() -
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*
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*Purpose:
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* return and set abstract user fp control word
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* can modify EM_DENORMAL mask
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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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unsigned int _control87(unsigned int newctrl, unsigned int mask)
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{
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unsigned __int64 oldCw;
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unsigned __int64 newCw;
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unsigned int oldabs;
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unsigned int newabs;
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oldCw = _get_fpsr();
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oldabs = _abstract_cw(oldCw);
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newabs = (newctrl & mask) | (oldabs & ~mask);
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newCw = _hw_cw(newabs) | (oldCw & ~(unsigned __int64)CWMASK);
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_set_fpsr(newCw);
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return newabs;
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} /* _control87() */
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/*** _controlfp
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*() -
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*
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*Purpose:
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* return and set abstract user fp control word
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* cannot change denormal mask (ignores _EM_DENORMAL)
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* This is done for portable IEEE behavior on all platforms
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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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unsigned int _controlfp(unsigned int newctrl, unsigned int mask)
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{
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return _control87(newctrl, mask & ~_EM_DENORMAL);
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}
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/***
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* _abstract_cw() - abstract control word
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*
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*Purpose:
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* produce a fp control word in abstracted (machine independent) form
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*
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*Entry:
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* cw: machine control word
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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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unsigned int _abstract_cw(unsigned __int64 cw)
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{
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unsigned int abstr = 0;
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//
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// Set exception mask bits
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//
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if (cw & IEM_INVALID)
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abstr |= _EM_INVALID;
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if (cw & IEM_ZERODIVIDE)
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abstr |= _EM_ZERODIVIDE;
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if (cw & IEM_OVERFLOW)
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abstr |= _EM_OVERFLOW;
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if (cw & IEM_UNDERFLOW)
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abstr |= _EM_UNDERFLOW;
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if (cw & IEM_INEXACT)
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abstr |= _EM_INEXACT;
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if (cw & IEM_DENORMAL)
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abstr |= _EM_DENORMAL;
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//
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// Set rounding mode
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//
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switch (cw & IMCW_RC) {
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case IRC_NEAR:
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abstr |= _RC_NEAR;
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break;
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case IRC_UP:
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abstr |= _RC_UP;
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break;
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case IRC_DOWN:
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abstr |= _RC_DOWN;
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break;
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case IRC_CHOP:
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abstr |= _RC_CHOP;
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break;
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}
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// Flush to zero mode
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if (cw & FTZ) {
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abstr |= _DN_FLUSH;
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}
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//
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// Set Precision mode
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//
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switch (cw & IMCW_PC) {
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case IPC_64:
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abstr |= _PC_64;
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break;
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case IPC_53:
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abstr |= _PC_53;
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break;
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case IPC_24:
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abstr |= _PC_24;
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break;
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}
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return abstr;
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}
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/***
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* _hw_cw() - h/w control word
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*
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*Purpose:
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* produce a machine dependent fp control word
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*
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*
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*Entry:
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* abstr: abstract control word
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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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unsigned __int64 _hw_cw(unsigned int abstr)
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{
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//
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// Set standard infinity and denormal control bits
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//
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unsigned __int64 cw = 0;
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//
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// Set exception mask bits
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//
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if (abstr & _EM_INVALID)
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cw |= IEM_INVALID;
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if (abstr & _EM_ZERODIVIDE)
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cw |= IEM_ZERODIVIDE;
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if (abstr & _EM_OVERFLOW)
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cw |= IEM_OVERFLOW;
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if (abstr & _EM_UNDERFLOW)
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cw |= IEM_UNDERFLOW;
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if (abstr & _EM_INEXACT)
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cw |= IEM_INEXACT;
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if (abstr & _EM_DENORMAL)
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cw |= IEM_DENORMAL;
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//
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// Set rounding mode
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//
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switch (abstr & _MCW_RC) {
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case _RC_NEAR:
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cw |= IRC_NEAR;
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break;
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case _RC_UP:
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cw |= IRC_UP;
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break;
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case _RC_DOWN:
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cw |= IRC_DOWN;
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break;
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case _RC_CHOP:
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cw |= IRC_CHOP;
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break;
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}
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// Flush to zero mode
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if (abstr & _DN_FLUSH) {
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cw |= FTZ;
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}
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//
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// Set Precision mode
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//
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switch (abstr & _MCW_PC) {
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case _PC_64:
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cw |= IPC_64;
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break;
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case _PC_53:
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cw |= IPC_53;
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break;
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case _PC_24:
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cw |= IPC_24;
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break;
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}
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return cw;
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}
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/***
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* _abstract_sw() - abstract fp status word
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*
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*Purpose:
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* produce an abstract (machine independent) fp status word
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*
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*
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*Entry:
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* sw: machine status word
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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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unsigned int _abstract_sw(unsigned __int64 sw)
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{
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unsigned int abstr = 0;
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if (sw & ISW_INVALID)
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abstr |= _SW_INVALID;
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if (sw & ISW_ZERODIVIDE)
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abstr |= _SW_ZERODIVIDE;
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if (sw & ISW_OVERFLOW)
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abstr |= _SW_OVERFLOW;
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if (sw & ISW_UNDERFLOW)
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abstr |= _SW_UNDERFLOW;
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if (sw & ISW_INEXACT)
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abstr |= _SW_INEXACT;
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if (sw & ISW_DENORMAL)
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abstr |= _SW_DENORMAL;
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return abstr;
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}
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/***
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* _fpreset() - reset fp system
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*
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*Purpose:
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* reset fp environment to the default state
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* Also reset saved fp environment if invoked from a user's
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* signal handler
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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 _fpreset()
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{
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unsigned __int64 status = ICW | 0x9004802700002; /* fpsr.sf1.pc=3, wre=1, traps.dd=1 */
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PEXCEPTION_POINTERS excptrs = (PEXCEPTION_POINTERS) _pxcptinfoptrs;
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//
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// reset fp state
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//
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_set_fpsr(status);
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if (excptrs &&
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excptrs->ContextRecord->ContextFlags & CONTEXT_FLOATING_POINT) {
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// _fpreset has been invoked by a signal handler which in turn
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// has been invoked by the CRT filter routine. In this case
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// the saved fp context should be cleared, so that the change take
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// effect on continuation.
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excptrs->ContextRecord->StFPSR = ICW;
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}
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}
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