Which processor instructions are used most commonly?

Question

My objective is to do comparative study of a few instruction set architectures.
For each instruction set architecture, how can i find the most commonly used instructions?

This is the steps i am thinking of:

• Find common ISAs for a chosen domain
• Find popular programs for each such ISA
• Disassemble the program instructions (.code) (which tool?)
• Collect statistics on instruction format, opcode, type. (which tool?)

Here is a very good study on x86 machine code statistics: https://www.strchr.com/x86_machine_code_statistics

I have tried below command for disassembling, but it does not seem to disassemble properly. Disassembled code shows some das instructions, which should not be present in actual code.

ndisasm -b32 -a $(which which)

Answer 1

You can try this, to gather mnemonics from .text section:

objdump --no-show-raw-insn \
        -M intel           \
        -sDj .text $(which *program name*) | # <-- disassemble .text section
             sed -n '/<\.text>/, $ p'      | # <-- skip raw hex
             awk '{$1 = ""; print}'        | # <-- remove offsets
             sed '1d'                        # <-- delete annoying <.text> in first line

After that you can either get only mnemonics name, appending awk '{print $1}' to previous command, or mutating data somehow different.

After all of this add sort | uniq -c to previous steps. So my resulting command looked like:

objdump --no-show-raw-insn \
        -M intel           \
        -sDj .text $(which *program name*) | 
             sed -n '/<\.text>/, $ p'      | 
             awk '{$1 = ""; print}'        |
             sed '1d'                      |
             awk '{print $1}' | sort | uniq -c

Which prints out frequencies of every mnemonic from program's text section