machine-instruction – Tarik Billa

What is the loop inversion technique?

January 24, 2023 by Tarik

while (condition) { … } Workflow: check condition; if false, jump to outside of loop; run one iteration; jump to top. if (condition) do { … } while (condition); Workflow: check condition; if false, jump to beyond the loop; run one iteration; check condition; if true, jump to step 3. Comparing these two you can … Read more

How was the first compiler written?

October 21, 2022 by Tarik

Assembly instructions are (generally) a direct mapping to opcodes, which are (multi-)byte values of machine code that can be directly interpreted by the processor. It is quite possible to write a program in opcodes directly by looking them up from a table (such as this one for the 6039 microprocessor, for example) that lists them … Read more