gh-118335: Configure Tier 2 interpreter at build time (#118339)

The code for Tier 2 is now only compiled when configured
with `--enable-experimental-jit[=yes|interpreter]`.

We drop support for `PYTHON_UOPS` and -`Xuops`,
but you can disable the interpreter or JIT
at runtime by setting `PYTHON_JIT=0`.
You can also build it without enabling it by default
using `--enable-experimental-jit=yes-off`;
enable with `PYTHON_JIT=1`.

On Windows, the `build.bat` script supports
`--experimental-jit`, `--experimental-jit-off`,
`--experimental-interpreter`.

In the C code, `_Py_JIT` is defined as before
when the JIT is enabled; the new variable
`_Py_TIER2` is defined when the JIT *or* the
interpreter is enabled. It is actually a bitmask:
1: JIT; 2: default-off; 4: interpreter.
This commit is contained in:
Guido van Rossum 2024-04-30 18:26:34 -07:00 committed by GitHub
parent 9c468e2c5d
commit 7d83f7bcc4
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
32 changed files with 181 additions and 42 deletions

View file

@ -2492,6 +2492,7 @@
(void)this_instr;
next_instr += 1;
INSTRUCTION_STATS(ENTER_EXECUTOR);
#ifdef _Py_TIER2
int prevoparg = oparg;
CHECK_EVAL_BREAKER();
if (this_instr->op.code != ENTER_EXECUTOR ||
@ -2508,6 +2509,9 @@
tstate->previous_executor = Py_None;
Py_INCREF(executor);
GOTO_TIER_TWO(executor);
#else
Py_FatalError("ENTER_EXECUTOR is not supported in this build");
#endif /* _Py_TIER2 */
DISPATCH();
}
@ -3432,6 +3436,7 @@
CHECK_EVAL_BREAKER();
assert(oparg <= INSTR_OFFSET());
JUMPBY(-oparg);
#ifdef _Py_TIER2
#if ENABLE_SPECIALIZATION
_Py_BackoffCounter counter = this_instr[1].counter;
if (backoff_counter_triggers(counter) && this_instr->op.code == JUMP_BACKWARD) {
@ -3457,6 +3462,7 @@
ADVANCE_ADAPTIVE_COUNTER(this_instr[1].counter);
}
#endif /* ENABLE_SPECIALIZATION */
#endif /* _Py_TIER2 */
DISPATCH();
}