what is the mean of instruction mix ?

[kewenpan]

Recently i have read some professional books on instruction set .
i have some questions about instruction for your help.
these are the followed:
one.what is the mean of instruction mix?
i am not sure that instrution mix means put instrutions of variou cpi value together ?
how to caculate cpi of threads?
threads consists of variou instructions ,such as load/store instruction ,branch .......
cpi of threads = sumof (percentage of each instruction * cpi of instruction)?

two .what is relation ofinstructions mixandprogram performance?
instruction mix could improve the performance of program , why?

thank you for your reading and looking forward to your advice.

[TimP]

Instruction mix profiles might be gathered in order to get a rough idea about which instructions are most important to the performance of a workload. Considering that pipelined CPUs have been the norm for decades, and hyperthreads have been in and out of favor for years also, references which ignore those characteristics don't appear very useful.
Did you read in the AVX forum about the free Intel tools for collecting instruction mix?