Beginning x64 Assembly Programming: From Novice to AVX Professional

© Jo Van Hoey 2019

J. Van HoeyBeginning x64 Assembly Programminghttps://doi.org/10.1007/978-1-4842-5076-1_34

34. SSE String Masks

Jo Van Hoey¹ 

(1)

Hamme, Belgium

 

Now that we know how to shuffle, we can discuss string masks.

Remember that SSE provides two string manipulation instructions that use a mask: pcmpistrm and pcmpestrm. We will be using implicit length instructions. At first, using masks looks complicated, but once you get the hang of it, you will see how powerful masking can be.

Searching for Characters

Listing 34-1, Listing 34-4, and Listing 34-3 show the example.

; sse_string4.asm

; find a character

extern print16b

extern printf

section .data

      string1      db    "qdacdekkfijlmdoza"

                   db    "becdfgdklkmdddaf"

                   db    "fffffffdedeee",10,0 ...