gh-146455: Fix O(N²) in add_const() after constant folding moved to CFG (GH-146456)
The add_const() function in flowgraph.c uses a linear search over the
consts list to find the index of a constant. After gh-126835 moved
constant folding from the AST optimizer to the CFG optimizer, this
function is now called N times for N inner tuple elements during
fold_tuple_of_constants(), resulting in O(N²) total time.
Fix by maintaining an auxiliary _Py_hashtable_t that maps object
pointers to their indices in the consts list, providing O(1) lookup.
For a file with 100,000 constant 2-tuples:
- Before: 10.38s (add_const occupies 83.76% of CPU time)
- After: 1.48s
(cherry picked from commit 5d416324c5)
Co-authored-by: zSirius <107359899+zSirius@users.noreply.github.com>
gh-148973: fix segfault on mismatch between consts size and oparg in compiler (GH-148974)
(cherry picked from commit c650b51c32)
Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
This moves the deprecation warning from compile time to run time.
(cherry picked from commit 86c3316183)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
We were incorrectly handling a few opcodes that leave their operands on the stack. Treat all of these conservatively; assume that they always leave operands on the stack.
(cherry picked from commit 6b77af257c)
In certain cases it's possible for locals loaded by `LOAD_FAST` instructions
to be on the stack when the local is killed by `DEL_FAST`. These `LOAD_FAST`
instructions should not be optimized into `LOAD_FAST_BORROW` as the strong
reference in the frame is killed while there is still a reference on the stack.
The function indicates whether or not the function has a return statement.
This is used by a later change related treating some functions like scripts.
Optimize `LOAD_FAST` opcodes into faster versions that load borrowed references onto the operand stack when we can prove that the lifetime of the local outlives the lifetime of the temporary that is loaded onto the stack.
Move some `#include <stdbool.h>` after `#include "Python.h"` when `pyconfig.h` is not
included first and when we are in a platform-agnostic context. This is to avoid having
features defined by `stdbool.h` before those decided by `Python.h`.
Codegen phase has an optimization that transforms
```
LOAD_CONST x
LOAD_CONST y
LOAD_CONXT z
BUILD_LIST/BUILD_SET (3)
```
->
```
BUILD_LIST/BUILD_SET (0)
LOAD_CONST (x, y, z)
LIST_EXTEND/SET_UPDATE 1
```
This optimization has now been moved to CFG phase to make #128802 work.
Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
Co-authored-by: Yan Yanchii <yyanchiy@gmail.com>
