New submission from Brandt Bucher <brandtbuc...@gmail.com>:
...as discussed in https://github.com/faster-cpython/ideas/discussions/228. We can dramatically simplify our stack manipulations by getting rid of the `DUP_TOP*` and `ROT_*` families of instructions: - Replace `DUP_TOP` with `COPY(1)`. - Replace `DUP_TOP_TWO` with `COPY(2), COPY(2)`. - Introduce a new `SWAP` instruction. - Replace `ROT_TWO` with `SWAP(2)`. - Replace `ROT_THREE` with `SWAP(3), SWAP(2)`. - Remove `ROT_FOUR`. - Replace `ROT_N(n)` with `SWAP(n), SWAP(n - 1), ..., SWAP(2)`. It then becomes much simpler for the peephole optimizer to reason about code sequences involving these instructions (for example, it's pretty straightforward to truly *optimize* an arbitrary sequence of swaps). ---------- assignee: brandtbucher components: Interpreter Core messages: 411697 nosy: Mark.Shannon, brandtbucher priority: normal severity: normal status: open title: Simplify the VM's stack manipulations type: performance versions: Python 3.11 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue46528> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
