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No pattern found for opcode Fadd: Xxr

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
38/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
compilers

Research direction

Reproduce the failure with the provided Docker command and autogen_bug.py example. Start at the assertion in /cinder/src/Jit/codegen/autogen.cpp:143 and trace the reported “No pattern found for opcode Fadd: Xxr” case, comparing behavior with and without @inline. Done means the inline version no longer aborts with this assertion.

Written by the indexing model from the issue text.

Description

sp-correctness staticpython
$ docker run -v $PWD:/vol -it --rm ghcr.io/facebookincubator/cinder-runtime:cinder-3.8 -X jit -m compiler --static vol/autogen_bug.py
JIT: /cinder/src/Jit/codegen/autogen.cpp:143 -- assertion failed: func != nullptr
No pattern found for opcode Fadd: Xxr
from __static__ import box, double, inline

@inline
def foo(a: double, b: double) -> double:
    return b - a

def main():
    c: double = 0.
    for _ in range(10):
        c += foo(.4, .97)
    print('done', box(c))

if __name__ == '__main__':
    main()

The problem goes away if @inline is removed.

See in seen in cinder-3.8.6c2de94

Dominant language
Python
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