I was comparing the last preceding poke with the *last* peek,
rather than the *first* peek.
Unfortunately this bug obscured another bug:
When the last preceding poke is UNUSED, the first peek disappears,
leaving the variable unassigned. This is how I fixed it:
- Rename CopyEffect to CopyItem.
- Change CopyItem to contain StackItems instead of StackEffects.
- Update those StackItems when adjusting the manager higher or lower.
- Assert that those StackItems' offsets are equivalent.
- Other clever things.
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Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
This finishes the work begun in gh-107760. When, while projecting a superblock, we encounter a call to a short, simple function, the superblock will now enter the function using `_PUSH_FRAME`, continue through it, and leave it using `_POP_FRAME`, and then continue through the original code. Multiple frame pushes and pops are even possible. It is also possible to stop appending to the superblock in the middle of a called function, when running out of space or encountering an unsupported bytecode.
* Split `CALL_PY_EXACT_ARGS` into uops
This is only the first step for doing `CALL` in Tier 2.
The next step involves tracing into the called code object and back.
After that we'll have to do the remaining `CALL` specialization.
Finally we'll have to deal with `KW_NAMES`.
Note: this moves setting `frame->return_offset` directly in front of
`DISPATCH_INLINED()`, to make it easier to move it into `_PUSH_FRAME`.
- Generalize the syntax for the type of a stack effect to allow a trailing `*`,
so we can declare something as e.g. `PyCodeObject *`.
- When generating assignments for stack effects,
the type of the value on the stack should be the default (i.e., `PyObject *`)
even when the variable copied to/from it has a different type,
so that an appropriate cast is generated
However, not when the variable is an array --
then the type is taken from the variable (as it is always `PyObject **`).
Introducing a new file, stacking.py, that takes over several responsibilities related to symbolic evaluation of push/pop operations, with more generality.