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GeezerVison is showing github.com — gh-130415: Narrow types to constants in branches involving specialized comparisons with a constant by reidenong · Pull Request #144150 · python/cpython

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@reidenong

@reidenong reidenong commented Jan 22, 2026 •
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This uses the new predicate optimizer symbol to narrow types to constants in branches involving comparisons with a constant.

This PR provides the implementation for _COMPARE_OP_INT , _COMPARE_OP_STR, _COMPARE_OP_FLOAT.

  • Issue: Better constant narrowing in the JIT optimizer #130415

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reidenong added 2 commits January 22, 2026 20:04
@reidenong
Add failing regression tests
de4c33f
@reidenong
Add constant narrowing for _COMPARE_OP_INT
ddd202a
@reidenong
reidenong requested review from Fidget-Spinner, markshannon, savannahostrowski and tomasr8 as code owners January 22, 2026 13:30
@bedevere-app bedevere-app Bot mentioned this pull request Jan 22, 2026
Better constant narrowing in the JIT optimizer #130415
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@bedevere-app bedevere-app Bot added the awaiting review label Jan 22, 2026
reidenong added 3 commits January 22, 2026 22:24
@reidenong
Refine unit test names
030bc28
@reidenong
Add failing unit tests for float EQ, NE
7a03b22
@reidenong
Add constant narrowing for float EQ, NE
eaf3f23
@reidenong

reidenong commented Jan 22, 2026

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After discussion with Ken Jin I will be adding implementations for all _COMPARE_OP_* in this PR
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reidenong added 4 commits January 22, 2026 22:45
@reidenong
Fix whitespace
2b5e3e0
@reidenong
Refine unit tests
57ee7f3
@reidenong
Add failing unit tests for str comparison
b8b217b
@reidenong
Add constant narrowing for str EQ, NE
08c1464
@reidenong reidenong changed the title gh-130415: Narrow types to constants in branches involving comparisons with a constant gh-130415: Narrow types to constants in branches involving specialized comparisons with a constant Jan 22, 2026
Fidget-Spinner
Fidget-Spinner approved these changes Jan 24, 2026
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@bedevere-app bedevere-app Bot added awaiting merge and removed awaiting review labels Jan 24, 2026
@Fidget-Spinner Fidget-Spinner added the skip news label Jan 24, 2026
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Fidget-Spinner merged commit 6d972e0 into python:main Jan 24, 2026
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@bedevere-app bedevere-app Bot removed the awaiting merge label Jan 24, 2026
thunder-coding pushed a commit to thunder-coding/cpython that referenced this pull request Feb 15, 2026
@reidenong @thunder-coding
pythongh-130415: Narrow types to constants in branches involving spec…
fe0b289 
…ialized comparisons with a constant (pythonGH-144150)
@reidenong
reidenong deleted the narrow-types-to-constants-for-int-comparisons branch September 2, 2026 04:20
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@Fidget-Spinner Fidget-Spinner Fidget-Spinner approved these changes
@markshannon markshannon Awaiting requested review from markshannon markshannon is a code owner
@tomasr8 tomasr8 Awaiting requested review from tomasr8 tomasr8 is a code owner
@savannahostrowski savannahostrowski Awaiting requested review from savannahostrowski

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@reidenong @Fidget-Spinner
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