How to read the "Intel Intrinsics Guide"?

I am trying to get started with AVX512 intrinsics by reading the Intel Intrinsics Guide but so far I have found that it does not define the named datatypes or the pseudocode syntax used for explanation. Without such definitions, the so-called guide is not guiding me in the least.

For example, if I look up the function _mm512_slli_epi32 (__m512i a, unsigned int imm8) which takes a vector a of packed 32-bit integers and does something to it, the guide says the result is stored in something called dst (undefined) and the operation is as follows.

FOR j := 0 to 15
    i := j*32
    IF imm8[7:0] > 31
        dst[i+31:i] := 0
    ELSE
        dst[i+31:i] := ZeroExtend32(a[i+31:i] << imm8[7:0])
    FI
ENDFOR
dst[MAX:512] := 0

What on earth am I supposed to make out of this without proper documentation? There isn't even a link to documentation on the syntax used.

Kindly help. I am looking for a guide to "Intel Intrinsics Guide". Alternatively, I would also appreciate any other pedagogical introduction to Intel intrinsics. This answer does not help. Thanks!

Solution

Intel calls dst the return value of the instruction. Overall, that instruction does this:

inline std::array<int, 16> slli( std::array<int, 16> a, int imm )
{
    for( int& tmp : a )
        tmp = ( imm > 31 ) ? 0 : tmp << imm;
    return a;
}

Here’s my article: http://const.me/articles/simd/simd.pdf I hope a good introduction.