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Diffstat (limited to 'src/include/i386/ctrl87.h')
| -rw-r--r-- | src/include/i386/ctrl87.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/src/include/i386/ctrl87.h b/src/include/i386/ctrl87.h new file mode 100644 index 0000000..02b4490 --- /dev/null +++ b/src/include/i386/ctrl87.h @@ -0,0 +1,120 @@ +/* + * This file is part of ms-dos port for XaoS + * ctrl87.h + * + */ + + +#ifndef __CONTROL87_H__ + + +#define __CONTROL87_H__ + + +#ifdef __CONTROL87_C__ +#define EXTERN +#else +#define EXTERN extern +#endif + + +/* 8087/80287 Status Word format */ + +#define SW_INVALID 0x0001 /* Invalid operation */ +#define SW_DENORMAL 0x0002 /* Denormalized operand */ +#define SW_ZERODIVIDE 0x0004 /* Zero divide */ +#define SW_OVERFLOW 0x0008 /* Overflow */ +#define SW_UNDERFLOW 0x0010 /* Underflow */ +#define SW_INEXACT 0x0020 /* Precision (Inexact result) */ + +/* 8087/80287 Control Word format */ + +#define MCW_EM 0x003f /* interrupt Exception Masks */ +#define EM_INVALID 0x0001 /* invalid */ +#define EM_DENORMAL 0x0002 /* denormal */ +#define EM_ZERODIVIDE 0x0004 /* zero divide */ +#define EM_OVERFLOW 0x0008 /* overflow */ +#define EM_UNDERFLOW 0x0010 /* underflow */ +#define EM_INEXACT 0x0020 /* inexact (precision) */ + +#define MCW_IC 0x1000 /* Infinity Control */ +#define IC_AFFINE 0x1000 /* affine */ +#define IC_PROJECTIVE 0x0000 /* projective */ + +#define MCW_RC 0x0c00 /* Rounding Control */ +#define RC_CHOP 0x0c00 /* chop */ +#define RC_UP 0x0800 /* up */ +#define RC_DOWN 0x0400 /* down */ +#define RC_NEAR 0x0000 /* near */ + +#define MCW_PC 0x0300 /* Precision Control */ +#define PC_24 0x0000 /* 24 bits */ +#define PC_53 0x0200 /* 53 bits */ +#define PC_64 0x0300 /* 64 bits */ + +/**************************************************************************/ +/************************* Type declarations **************************/ +/**************************************************************************/ + +/**************************************************************************/ +/************************ Function declarations ***********************/ +/**************************************************************************/ + +/* + _control87 changes floating-point control word. + + Declaration: + ------------ + unsigned short _control87(unsigned short newcw, unsigned short mask); + + Remarks: + -------- + _control87 retrieves or changes the floating-point control word. + + The floating-point control word is an unsigned short that specifies the + following modes in the 80x87 FPU: + o allowed exceptions + o infinity mode + o rounding mode + o precision mode + + Changing these modes allows you to mask or unmask floating-point exceptions. + + _control87 matches the bits in mask to the bits in newcw. + + If any mask bit = 1, the corresponding bit in newcw contains the new value + for the same bit in the floating-point control word. + + If mask = 0000, _control87 returns the floating-point control word without + altering it. + + Examples: + --------- + Switching to projective infinity mode: + _control87(IC_PROJECTIVE, MCW_IC); + + Disabling all exceptions: + _control87(MCW_EM, MCW_EM); + + Return Value: + ------------- + The bits in the value returned reflect the new floating-point control word. +*/ +EXTERN unsigned short _control87(unsigned short, unsigned short); + + +/**************************************************************************/ +/************************** Global variables **************************/ +/**************************************************************************/ + + + +#ifdef __CONTROL87_C__ +#else +#endif + + +#undef EXTERN + + +#endif |