# DRAFT List of 2-arg opcodes

These are A-Form, recommended Major Opcode 63 for full-width
and 59 for half-width (ending in s).

| 0.5|6.10|11.15|16.20| 21.25 | 26.30 |31| name          |  Form   |
| -- | -- | --- | --- | ----- | ----- |--| ----          | ------- |
| NN |FRT | FRA | FRB  | ///  | xxxxx |Rc| trigonometric | A-Form  |

As shown in Power ISA 3.1 Book III Appendix D Table 28 p1190
and Table 23 p1368,
Major Opcode 63 has room
for 9 A-Form 5-bit XO instructions,
Major Opcode 59 has 11 5-bit XO instructions,
with some overlap leading to a partially orthogonal
set across full and half width.

| opcode    | Description            | Major 63         | Major 59    |
| ------    | ----------------       | ---------------- | ----------- |
| fatan2(s) | atan2 arc tangent      | 00001            | 00001       |
| fatan2pi(s)|atan2 arc tangent / pi | 01001            | 00111       |
| fpow(s)   | x power of y           | 10000            | 10000       |
| fpown(s)  | x power of n (n int)   | 10001            | 10001       |
| fpowr(s)  | x power of y (x +ve)   | 10011            | 10011       |
| frootn(s) | x power 1/n (n integer)| 11011            | 11011       |
| fhypot(s) | hypotenuse             | 01101            | 10111       |
 
# DRAFT List of 1-arg transcendental opcodes

These are X-Form, and are identical in Special Registers Altered to `fsqrt`.
Recommended Major Opcode 63 for full-width and 59 for half-width (ending in s).

Special Registers Altered:

    FPRF FR FI FX OX UX XX
    VXSNAN VXIMZ VXZDZ
    CR1                    (if Rc=1)

| 0.5|6.10|11.15|16.20| 21..30      |31| name      |  Form   |
| -- | -- | --- | --- | ----------  |--| ----      | ------- |
| NN |FRT | /// | FRB  | 1xxxx0111x |Rc| transcendental | X-Form  |

Recommended 10-bit XO with the low 5 LSBs 01100:

| opcode   | Description              | Major 59 and 63 |
| ------    | ----------------       | ---------------- |
| frsqrt(s)| Reciprocal Square-root   | 10000 01110     |
| fcbrt(s) | Cube Root                | 10001 01110     |
| frecip(s)| Reciprocal               | 10010 01111     |
| fexp2m1(s)| power-2 minus 1      | 10100 01110     |
| flog2p1(s)| log2 plus 1               | 10101 01110     |
| fexp2(s) | power-of-2               | 10110 01110     |
| flog2(s) | log2                     | 10111 01111     |
| fexpm1(s)| exponential minus 1      | 11000 01110     |
| flogp1(s)| log plus 1               | 11001 01110     |
| fexp(s)  | exponential              | 11010 01110     |
| flog(s)  | natural log (base e)     | 11011 01111     |
| fexp10m1(s)| power-10 minus 1      | 11100 01110     |
| flog10p1(s)| log10 plus 1               | 11101 01110     |
| fexp10(s)| power-of-10              | 11110 01110     |
| flog10(s)| log base 10              |11111 01111     |

# DRAFT List of 1-arg trigonometric opcodes
 
These are X-Form, and are identical in Special Registers Altered to `fsqrt`.
Recommended Major Opcode 63 for full-width and 59 for half-width (ending in s)

Special Registers Altered:

    FPRF FR FI FX OX UX XX
    VXSNAN VXIMZ VXZDZ
    CR1                    (if Rc=1)

| 0.5|6.10|11.15|16.20| 21..30      |31| name      |  Form   |
| -- | -- | --- | --- | ----------  |--| ----      | ------- |
| NN |FRT | /// | FRB  | 10xxx011xx |Rc| trigonometric | X-Form  |

Recommended 10-bit XO with the low 5 LSBs 01101 to 01111:

| opcode      | Description              | Major 59 and 63 |
| ------    | ----------------       | ----------------   |
| fsin(s)     | sin (radians)            |  10000 01101   |
| fcos(s)     | cos (radians)            |  10000 01110    |
| ftan(s)     | tan (radians)            |  10000 01111   |
| fasin(s)    | arcsin (radians)         |  10001 01101    |
| facos(s)    | arccos (radians)         |  10001 01110    |
| fatan(s)    | arctan (radians)         |  10001 01111    |
| fsinpi(s)   | sin times pi             |  10010 01101    |
| fcospi(s)   | cos times pi             |  10010 01110    |
| ftanpi(s)   | tan times pi             |  10010 01111    |
| fasinpi(s)  | arcsin / pi              |  10011 01101    |
| facospi(s)  | arccos / pi              |  10011 01110    |
| fatanpi(s)  | arctan / pi              |  10011 01111    |
| fsinh(s)    | hyperbolic sin (radians) |  10100 01101    |
| fcosh(s)    | hyperbolic cos (radians) |  10100 01110    |
| ftanh(s)    | hyperbolic tan (radians) |  10100 01111    |
| fasinh(s)   | inverse hyperbolic sin   |  10101 01111    |
| facosh(s)   | inverse hyperbolic cos   |  10101 01111    |
| fatanh(s)   | inverse hyperbolic tan   |  10101 01111    |