logp - vs
Microsoft DirectX 9.0 SDK Update (October 2004)

logp - vs


Partial precision logp2(x).

Syntax

logp dst, src

where

Remarks

Vertex shader versions1_12_02_x2_sw3_03_sw
logpxxxxxx

The following code fragment shows the operations performed.

float f = abs(src);
if (f != 0)
    dest.x = dest.y = dest.z = dest.w = (float)(log(f)/log(2));
else
    dest.x = dest.y = dest.z = dest.w = -FLT_MAX;   

This instruction provides logarithm base 2 partial precision, up to 10 bits.



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