Microsoft DirectX 8.0 (C++) |
The Direct3DX vertex shader assembler provides macro instructions for application convenience in performing common simple operations. These macros are expanded by the driver into some of the standard vertex shader instructions, for details see the reference topic for each macro instruction.
exp | Exponential base 2 full precision |
frc | Fraction |
log | Logarithm base 2 full precision |
m3x2 | 3×2 vector matrix multiply |
m3x3 | 3×3 vector matrix multiply |
m3x4 | 3×4 vector matrix multiply |
m4x3 | 4×3 vector matrix multiply |
m4x4 | 4×4 vector matrix multiply |
For the purpose of determining if you exceed the maximum instruction count limit of 128, the macro instructions are guaranteed to expand to no more than the number of actual instructions listed.
Because these are passed to the implementation in the same manner as true instructions, the implementation is free to optimize them. Therefore, no assumptions can be made about timing cycle counts required.