The document discusses the 8087 numeric co-processor and its instruction set for performing complex mathematical calculations. It describes various compare instructions like FCOM, FCOMP, FCOMPP, F1COM, F1COMP, and FTST that compare operands and set status flags. It also explains transcendental instructions like F2XM1, FYL2XP1, FYL2X, FPTAN, and FPATAN that perform operations such as logarithmic, exponential and trigonometric functions. Exceptions caused by instructions and examples of usage are also provided.

1. 8087 INSTRUCTION SET-
COMPARE AND
TRANSCENDENTAL.
Presented By,
Karan Onkar
Punjabi. Padwal.
Shweta Dimpal
Pinjarkar. Patil.

2. 8087 Numeric Co-Processor.
 The 8086 instruction set is not capable of performing
complex mathematical calculations, word operations,
etc.
 In order to perform complex operation efficiently, the
Intel has developed 8087 numeric data processor.

3. Compare Group.
The comparison instruction compare data at the top of
the stack (TOS), in relation to another element; and
return the result of comparison in the status register
condition code bits.

4. FCOM: Compare – Real.
 Description : Compares top of stack to the source
operand.
 Operation : Takes current top of stack and compares it
with the source. If instruction is executed
without a specific source operand then source
operand can be a register on the stack or
memory location.
 Syntax : FCOM source_operand,
FCOM (no operand).
 Exception
Flag : I,D.
 Example : FCOM, FCOM real_long,
FCOM real_short.

5. FCOMP : Compare Real and Pop.
 Description : Compares source and TOS and then
POPs the TOS.
 Operation : This instruction takes current top of the
stack, compares it with the source
operand, and then pops the stack.
 Syntax : FCOMP source_operand.
FCOMP (no operand).
 Exception : I,D.
Flag
 Example : FCOMP real_long,
FCOMP real_short.

6. FCOMPP : Compare Real and Pop
twice.
 Description : Compares TOS and ST(1), pops it
twice.
 Operation : This instruction compares TOS to
ST(1) of stack and pops stack
register twice.
 Syntax : FCOMPP (no operand).
 Exception : I,D.
Flag
 Example : FCOMPP

7. F1COM : Integer Compare.
 Description : Compares TOS and source.
 Operation : This instruction converts source
operand to temporary real and
compares TOS to it.
 Syntax : F1COM source_opreand.
 Exception : I,D.
Flag
 Example : F1COM INT_WORD,
F1COM INT_SHORT.

8. F1COMP : Integer Compare and
Pop.
 Description : Compares TOS and source, pops
TOS.
 Operation : This instruction converts source
operand to temporary real and compares
TOS to it. In addition it pops the top of
stack.
 Syntax : F1COMP source_opreand.
 Exception : I,D.
Flag
 Example : F1COMP INT_WORD,
F1COMP INT_SHORT.

9. FTST – TEST.
 Description : Compares TOS and set condition
codes.
 Operation : This instruction compares contents
of TOS register ST with + 0.0.
 Syntax : FTST (no operand).
 Exception : I,D.
Flag
 Example : FTST.

10. FXAM.
 Description : Sets condition codes of status word
on exam.
 Operation : This instruction examines contents
of TOS and register ST.
 Syntax : FXAM (no operand).
 Exception : NONE.
Flag
 Example : FXAM.

11. TRANSCENDENTAL GROUP.
All transcendental instructions, use ST or ST(1) as their
operands. Result is stored back in the stack.

12. F2XM1 : 2 raised to X Power 1.
 Description : Calculates 2 raised to X Power 1.
 Operation : This instruction calculates the ST(0)
function, where X=Top of stack 2
raised to X Power 1.
 Syntax : F2XM1 (no operand).
 Exception : NONE.
Flag
 Example : F2XM1.

13. FYL2XP1 : Y*log2(X+1).
 Description : Calculates Y*log2 (X+1).
 Operation : This instruction gets X value from
top of stack, ST, Y value from ST(1),
pops the stack and returns the result
of the calculation to the top of stack
register ST.
 Syntax : FYL2XP1 (no operand).
 Exception : P.
Flag
 Example : FYL2XP1.

14. FYL2X: Y log2 X.
 Description : Calculates Y log2 X.
 Operation : This instruction gets X value from top
of stack, ST, Y value from ST(1). The
instruction next pops the stack and
stores the calculated result back on
the stack, ST.
 Syntax : FYL2X (no operand).
 Exception : P.
Flag
 Example : FYL2X.

15. FPTAN : Partial Tangent.
 Description : Calculates tangent of an angle.
 Operation : This instruction computes Y/X=tan θ of
an angle. Range for θ is 0< θ < π / 4 and
is taken from top of the stack. Upon
completion, Y replaces θ on the stack.
Out of ranges values are not signaled.
Values of SIN, COS and so must be
derived form this operand.
 Syntax : FPTAN (no operand).
 Exception : I,P.
Flag
 Example : FPTAN.

16. FPATAN : Partial Arctangent of a
Function.
 Description : Calculates arctangent of an function.
 Operation : This instruction pops X value from
current top of stack, pops stack a second
time, takes the now current TOS for Y value.
Calculates (Y/X) and returns result to TOS
register. Range of Y and X
0 ≤ Y<X< ∞
 Syntax : FPATAN (no operand).
 Exception : U,P.
Flag
 Example : FPATAN.