loop - ps

Starts a loop...endloop - ps block.

Syntax

loop aL, i#

 

Where:

• aL is the Loop Counter Register holding the current loop count.
• i# is a Constant Integer Register. See remarks.

Remarks

Pixel shader versions	1_1	1_2	1_3	1_4	2_0	2_x	2_sw	3_0	3_sw
loop								x	x

 

• The Loop Counter Register (aL) holds the current loop count and can be used for relative addressing into Input Color Register (v#) 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 by the loop block and has to be 0.
• Loop blocks may be nested. See Flow Control Limitations.
• 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, v2[ aL ]
endloop

Related topics

Pixel Shader Instructions