Intel 80287 - Page 380

OVERVIEW OF NUMERIC PROCESSING
Table 1-12.
Infinity Operands and Results
Operation Projective Result Affine Result
Addition
+00 plus +00
Invalid operation +00
-00 plus-oo
Invalid operation
-00
+00 plus-oo Invalid operation Invalid operation
-00 plus +00
Invalid operation Invalid operation
±oo plus ±X
'00 '00
±X plus ±oo
'00 '00
Subtraction
+00 minus -00
Invalid operation +00
-00 minus +00
Invalid operation
-00
+00 minus +00 Invalid operation Invalid operation
-00 minus -00
Invalid operation
Invalid operation
±oo minus ±X
'00 '00
±X minus ±oo
too too
Multiplication
±oo·±oo
E9
E9
±oo· ±y
E9
E9
±O· ±oo, ±oo' ±O Invalid operation Invalid operation
Division
±oo -+- ±oo Invalid operation Invalid operation
±oo -+- ±X
E9 E9
±X -+- ±oo
E9 E9
FSQRT
-00
Invalid operation Invalid operation
+00
Invalid operation +00
FPREM
±oo rem
±oo Invalid operation Invalid operation
±oo rem
±X Invalid operation Invalid operation
±Y rem ±oo
'Y 'Y
±O rem ±oo
'0
'0
FRNDINT
±oo
'00 '00
FSCp..LE
± 00 scaled by ± 00 Invalid operation Invalid operation
±
00 scaled by ± X
'00 '00
± 0 scaled by ± 00
'0 '0
± Y scaled by ± 00 Invalid operation Invalid operation
FXTRACT
±oo Invalid operation Invalid operation
Compare
±oo:
±oo
A=B -00 < +00
±oo: ±Y A ? B (and) invalid operation
-00 <Y < +00
±oo: ±O A '? 8 (andi invaiiu UI-'tll i:liiu;-I
___ n __
v.J_V_I.......,
FTST
±oo A ? B (and) invalid operation
'00
NOTES:
X zero or nonzero operand
Y nonzero operand
sign of original operand
1-28
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