dp4 - ps
Computes the four-component dot product of the source registers.
|dp4 dst, src0, src1|
- dst is the destination register.
- src0 is a source register.
- src1 is a source register.
|Pixel shader versions||1_1||1_2||1_3||1_4||2_0||2_x||2_sw||3_0||3_sw|
The following code snippet shows the operations performed:
dest.x = dest.y = dest.z = dest.w = (src0.x * src1.x) + (src0.y * src1.y) + (src0.z * src1.z) + (src0.w * src1.w);
Limitations for ps_1_2 and ps_1_3:
- Each shader can use up to a maximum of four dp4 instructions.
- Each dp4 instruction counts as two arithmetic instructions.
Limitations for 1_X versions:
- This instruction cannot be co-issued because dp4 runs in both the vector and alpha pipeline.