loop - vs
Start a loop...endloop block.
Syntax
Where:
Remarks
Vertex shader versions |
1_1 |
2_0 |
2_x |
2_sw |
3_0 |
3_sw |
loop |
|
x |
x |
x |
x |
x |
- The Loop Counter Register (aL) holds the current loop count, and can be used for relative addressing into Constant Integer Register (c#) or Output Registers (o#) inside the loop block.
- i#.x specifies the iteration count. The legal range is [0, 255]. Note that this instruction does not increment or decrement the value of i#.x.
- i#.y specifies the initial value of the Loop Counter Register (aL) register. The legal range is [0, 255]. Note that this instruction does not increment or decrement the value of i#.y.
- i#.z specifies the step/stride size. The legal range is [-128, 127].
- i#.w is not used and must be set to 0.
- Loop blocks may be nested. See Flow Control Nesting Limits.
- When nested, the value of the Loop Counter Register (aL) refers to the immediate enclosing loop block.
- Loop blocks are allowed to be either completely inside an if* block or completely surrounding it. No straddling is allowed.
Example
loop aL, i3
add r1, r0, c2[aL]
endloop