ARM, x86 and RISC-V Microprocessors Compared
A comparison of different design choices in the assembly language of three important microprocessor instruction-sets.
In the PC world x86 microprocessor from AMD and Intel dominate. On tablets and smartphones ARM chips from Qualcomm and Apple dominate. RISC-V is a new microprocessor instruction-set which various companies are starting to use.
Thus for those with some interest in assembly programming, I thought I would do a comparison of these chips, in how they deal with common operations and the rational for their differences.
Find this story hard to follow? Read: How Does a Modern Microprocessor Work?
Instruction Length
For RISC microprocessors such as ARM and RISC-V this is simply. Every instruction is 32-bit long (4-bytes). This is very common for RISC microprocessors: ARM, MIPS, RISC-V and PowerPC all use fixed length 32-bit instructions.
However don’t confuse this with whether it is a 64-bit or 32-bit microprocessor. A 64-bit microprocessor will typically have 64-bit registers which it can work on. However the instructions themselves will still typically be 32-bit. The reason is simple: You generally don’t need as much space as 64-bit for an…
