if pred - ps

Start of an if bool - ps...else - ps...endif - ps block, with the condition taken from the content of the predicate register.

Syntax

if [!]pred.replicateSwizzle

Where:

[!] is an optional NOT modifier. This modifies the value in the predicate register.
pred is the Predicate Register.
replicateSwizzle is a single component that is copied (or replicated) to all four components (swizzled). Valid components are: [x, y, z, w] or [r, g, b, a].

Remarks

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

This instruction is used to skip a block of code, based on a channel of the predicate register. Each if_pred block must end with an else - ps or endif - ps instruction.

Restrictions include:

if_pred blocks can be nested. This counts to the total dynamic nesting depth along with if_comp blocks.

An if_pred block cannot straddle a loop block; it should either be completely inside it or surround it.