"Made up of" isn't helpful. All assembly languages are equivalent to a sequence of bit operations. (…if you ignore side effects and memory operations.)
So you take your assembly instructions, write a sufficiently good model of assembly instructions<>bit operations, write a cost model (byte size of the assembly works as a cheap one), and then search for assembly instructions that perform the equivalent operation and minimize the cost model.
You're missing forest for the trees and lacking information to discuss this really. Check out this paper and similar ones if you want to learn about this area: https://arxiv.org/pdf/1711.04422
Answer: Verilog or VHDL. And these all synthesize down to AND/OR/XOR gates and eventually converted into NAND gates only.
Every assembly language statement is either data movement, or logic, or some combination of the two.
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We are talking about SAT solvers and superoptimizers. Are you at all familiar with this domain? Or have you even done a basic search on what the subject matter is?