Intel 8253 - Page 72

Intel387
TM
SX MATH COPROCESSOR
Encoding Clock Count Range
Instruction
Byte 0 Byte 1
Optional 32-Bit 32-Bit 64-Bit 16-Bit
Bytes 2–6 Real Integer Real Integer
ARITHMETIC
FADD
e
Add
Integer/real memory to ST(0) ESC MF 0 MOD 000 R/M SIB/DISP 14–31 36–58 19–38 38– 64
ST(i) and ST(0) ESCdP0 11000 ST(i) SIB/DISP 12–26
b
FSUB
e
Subtract
Integer/real memory with ST(0) ESC MF 0 MOD 10 R R/M SIB/DISP 14 –31 36–58 19–38 38 –64
c
ST(i) to ST(0) ESCdP0 1110 R R/M 12–26
d
FMUL
e
Multiply
Integer/real memory with ST(0) ESC MF 0 MOD 001 R/M SIB/DISP 21–33 45–73 27–57 46–74
ST(i) and ST(0) ESCdP0 1100 1 R/M 17–50
e
FDIV
e
Divide
Integer/real memory with ST(0) ESC MF 0 MOD 11 R R/M SIB/DISP 79 –87 103 –116
f
85–95 105–124
g
ST(i) and ST(0) ESCdP0 1111 R R/M 77–80
h
FSQRT
i
e
Square root ESC 001 1111 1010 97–111
FSCALE
e
Scale ST(0) by ST(1) ESC 001 1111 1101 44–82
FPREM
e
Partial remainder ESC 001 1111 1000 56 –140
FPREM1
e
Partial remainder (IEEE) ESC 001 1111 0101 81 – 168
FRNDINT
e
Round ST(0) to integer ESC 001 1111 1100 41–62
FXTRACT
e
Extract components
of ST(0)
ESC 001 1111 0100 42–63
FABS
e
Absolute value of ST(0) ESC 001 1110 0001 14–21
FCHS
e
Change sign of ST(0) ESC 001 1110 0000 17 – 24
TRANSCENDENTAL
FCOS
k
e
Cosine of ST(0) ESC 001 1111 1111 122–680
FPTAN
k
e
Partial tangent of ST(0) ESC 001 1111 0010 162–430
j
FPATAN
e
Partial arctangent of ST(0) ESC 001 1111 0011 250 – 420
FSIN
k
e
Sine of ST(0) ESC 001 1111 1110 121–680
FSINCOS
k
e
Sine and cosine of ST(0) ESC 001 1111 1011 150– 650
F2XM1
l
e
2
ST(0)
b
1 ESC 001 1111 0000 167–410
FYL2X
m
e
ST(1) * log
2
ST(0) ESC 001 1111 0001 99–436
FYL2XP1
n
e
ST(1) * log
2
[
ST(0)
a
1.0
]
ESC 001 1111 1001 210–447
Shaded areas indicate instructions not available in 8087/80287.
NOTES:
b. Add 3 clocks to the range when d
e
1.
c. Add 1 clock to each range when R
e
1.
d. Add 3 clocks to the range when d
e
0.
e. typical
e
52 (When d
e
0, 46 – 54, typical
e
49).
f. Add 1 clock to the range when R
e
1.
g. 135 – 141 when R
e
1.
h. Add 3 clocks to the range when d
e
1.
i.
b
0
s
ST(0)
s
a %
.
j. These timings hold for operands in the range
l
x
l
k
q. For operands not in this range, up to 76 additional clocks may be
needed to reduce the operand.
k. 0
s
ST(0)
k
2
63
.
l.
b
1.0
s
ST(0)
s
1.0.
m. 0
s
ST(0)
k
%
,
b%
k
ST(1)
k
a %
.
n. 0
s
l
ST(0)
l
k
[
2-SQRT(2)
]
/2,
b%
k
ST(1)
k
a %
.
43
43