Stream: git-wasmtime

Topic: wasmtime / issue #1064 Optimize `stack_store` and `stack_...

Wasmtime GitHub notifications bot (May 04 2022 at 20:42):

cfallin labeled issue #1064:

Currently, stack_store and stack_load are legalized into stack_addr followed by plain store and load, producing code like this:

    lea rax, qword ptr [rsp + 8]
        mov qword ptr [rax], rdi

We really want to just emit this:

        mov qword ptr [rsp + 8], rdi

Options include:
- Add encoding rules for stack_load and stack_store, making them legal. This is straightforward, but if we later want to extend this to allow extending loads and narrowing stores, we'll need a bunch more instructions.
- Extend load_complex/store_complex to have a way represent a base pointer which is the stack pointer, and then fold stack_addr into load/store.

Wasmtime GitHub notifications bot (Sep 25 2025 at 21:32):

cfallin closed issue #1064:

Currently, stack_store and stack_load are legalized into stack_addr followed by plain store and load, producing code like this:

    lea rax, qword ptr [rsp + 8]
        mov qword ptr [rax], rdi

We really want to just emit this:

        mov qword ptr [rsp + 8], rdi

Options include:
- Add encoding rules for stack_load and stack_store, making them legal. This is straightforward, but if we later want to extend this to allow extending loads and narrowing stores, we'll need a bunch more instructions.
- Extend load_complex/store_complex to have a way represent a base pointer which is the stack pointer, and then fold stack_addr into load/store.

Last updated: Dec 13 2025 at 19:03 UTC