gh-93554: Conditional jumps only jump forward

[iritkatriel]

• Issue: Conditional backward edges should help "warm up" code #93554

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @iritkatriel for commit 8a3d017 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.

[brandtbucher]

Thanks for doing this!

Just curious, have you benchmarked this change?

[brandtbucher]

We might also consider adding a test that loops ending in branches can still quicken code.

For example, something like:

def f(x: bool) -> None:
    for i in range(1_000_000):
        if x:
            pass

Today f(True) quickens the code, but f(False) doesn't. After this change, both should.

Ditto for while loops. This code should be quickened after only one call:

def w() -> None:
    i = 0
    while i < 1_000_000:
        i += 1

[iritkatriel]

Just curious, have you benchmarked this change?

I haven't yet.

[markshannon]

Small speedup

[iritkatriel]

We might also consider adding a test that loops ending in branches can still quicken code.

For example, something like:

def f(x: bool) -> None:
    for i in range(1_000_000):
        if x:
            pass

Today f(True) quickens the code, but f(False) doesn't. After this change, both should.

Ditto for while loops. This code should be quickened after only one call:

def w() -> None:
    i = 0
    while i < 1_000_000:
        i += 1

Where does such a test belong?

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @iritkatriel for commit e87887c 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.

[iritkatriel]

I'll merge this while the buildbots are happy with it, we can add more tests (for specialisation etc) in a followup PR.