Set87ControlWord Procedure |
Unit
QESBPCSMath
Declaration
Procedure Set87ControlWord(const ControlWord: TESBBitList);
Description
15-12 Reserved
On 8087/80287 12 was Infinity Control
0 Projective
1 Affine
11-10 Rounding Control
00 Round to nearest even
01 Round Down
10 Round Up
11 Chop - Truncate towards Zero
9-8 Precision Control
00 24 bits Single Precision
01 Reserved
10 53 bits Double Precision
11 64 bits Extended Precision (Default)
7-6 Reserved
On 8087 7 was Interrupt Enable Mask
5 Precesion Exception Mask
4 Underflow Exception Mask
3 Overflow Exception Mask
2 Zero Divide Exception Mask
1 Denormalised Operand Exception Mask
0 Invalid Operation Exception Mask
Implementation
procedure Set87ControlWord (const ControlWord: TESBBitList); var Temp: Word; asm mov [Temp], ax // Move Control Word into Memory location fldcw [Temp] // Load '87 Control Word End; |
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