> That's no guarantee it would succeed though - AMD64 also cleaned up a number of warts on the x86 architecture, like more registers.
As someone who works with AMD64 assembly very often - they didn't really clean it up all that much. Instruction encoding is still horrible, you still have a bunch of useless instructions even in 64-bit mode which waste valuable encoding space, you still have a bunch of instructions which hardcode registers for no good reason (e.g. the shift instructions have a hardcoded rcx). The list goes on. They pretty much did almost the minimal amount of work to make it 64-bit, but didn't actually go very far when it comes to making it a clean 64-bit ISA.
I'd love to see what Intel came up, but I'd be surprised if they did a worse job.
As someone who works with AMD64 assembly very often - they didn't really clean it up all that much. Instruction encoding is still horrible, you still have a bunch of useless instructions even in 64-bit mode which waste valuable encoding space, you still have a bunch of instructions which hardcode registers for no good reason (e.g. the shift instructions have a hardcoded rcx). The list goes on. They pretty much did almost the minimal amount of work to make it 64-bit, but didn't actually go very far when it comes to making it a clean 64-bit ISA.
I'd love to see what Intel came up, but I'd be surprised if they did a worse job.