WASM is not quite a stack machine

7 hours ago

Wasm is commonly described as a stack machine but differs from other stack-based languages.
Traditional stack machines use operations like dup and swap to manipulate the stack, enabling value reuse and complex expressions.
Wasm lacks these stack manipulation instructions, making it more akin to a register machine with compound expressions encoded in postfix notation.
Wasm's design limits optimizations like common subexpression elimination without introducing variables.
The postfix notation in binary Wasm is just an encoding choice, not an inherent stack machine feature.
This distinction means experience with other stack-based VMs doesn't fully translate to Wasm.

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