Programming The Vertex Shader

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This information is only for the ones of you who are interested and have a bit of programming experience as well as a minimal understanding of 3D math.

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Instruction	Parameters	Action
nop	Row 0 - Cell 1	do nothing
mov	dest, src	move
mul	dest, src1, rc2	Set dest to the product of src1 and src2
add	dest, src1, rc2	Add src1 to src2. [And the optional negation creates subtraction]
mad	dest, src1, rc2, rc3	Multiply src1 by src2 and add src3 - into dst
rsq	dest, src	Reciprocal square root of src (much more useful than straight 'square root').dest.x = dest.y = dest.z = dest.w = 1/sqrt(src)
dp3	dest, src1, src2	3 Component dot product
dp4	dest, src1, src2	4 Component dot product
dst	dest, src1, src2	Calculate distance vector. src1 vector is (NA,dd,dd,NA) and src2 is (NA,1/d,NA,1/d).dest is set to (1,d,d*d,1/d)
lit	dest, src	Calculates lighting coefficients from two dot products and a power. src is:src.x = n o l (unit normal and light vectors)src.y = n o h (unit normal and halfangle vectors)src.z is unusedsrc.w = power (in range +128 to -128)
min	dest, src1, src2	Component-wise min operation
max	dest, src1, src2	Component-wise max operation
slt	dest, src1, src2	dest = (src1 < src2) ? 1 : 0
sge	dest, src1, src2	dst = (src1 >= src2) ? 1 : 0
expp	dest, src.w	dest.x = 2 (int)src.wdest.y = fractional part (src.w)dest.z = 2 src.wdest.w = 1.0
log	dest, src.w	dest.x = exponent((int)src.w)dest.y = mantissa(src.w)dest.z = log2(src.w)dest.w = 1.0
rcp	dest, src.w	dest.x = dest.y = dest.z = dest.w = 1 / src

These few instructions are already quite powerful. To make the handling easier, NVIDIA added a few more features, 'costless' negation and swizzling...