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markshannon opened this issue Mar 20, 2025 · 0 comments
Open

Top-of-stack caching in the interpreter #131498

markshannon opened this issue Mar 20, 2025 · 0 comments
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interpreter-core (Objects, Python, Grammar, and Parser dirs) performance Performance or resource usage type-feature A feature request or enhancement

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markshannon commented Mar 20, 2025 •
edited by bedevere-app bot
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Top-of-stack caching is technique where one or more values on the top of the stack are kept in local variables, with the assumption that the C compiler will put them in registers.

We should implement this for the interpreter (tier 1).
We cannot afford to increase the number of instructions by much, so we'll have to use a fixed size cache of 1.
This will likely only produce a modest speedup, as the total memory traffic is unlikely to decrease. There should be some ILP improvements.

The main benefit of TOS caching is likely to be in the JIT where we can use a variable sized cache.
We want to do it in the interpreter first though, as it will be simpler and requires a subset of the changes needed for the JIT.

Linked PRs
@bedevere-app bedevere-app bot mentioned this issue Mar 20, 2025
Merged
markshannon added a commit that referenced this issue Mar 20, 2025
@markshannon
GH-131498: Remove conditional stack effects (GH-131499)
7ebd71e 
* Adds some missing #includes
@picnixz picnixz added type-feature A feature request or enhancement interpreter-core (Objects, Python, Grammar, and Parser dirs) performance Performance or resource usage labels Mar 22, 2025
@brandtbucher brandtbucher mentioned this issue Mar 24, 2025
Closed
@bedevere-app bedevere-app bot mentioned this issue Mar 28, 2025
Merged
markshannon added a commit that referenced this issue Mar 31, 2025
@markshannon
GH-131498: Another refactoring of the code generator (GH-131827)
c535a13 
* Rename 'defined' attribute to 'in_local' to more accurately reflect how it is used

* Make death of variables explicit even for array variables.

* Convert in_memory from boolean to stack offset

* Don't apply liveness analyis to optimizer generated code

* Add 'out' parameter to stack.pop
@bedevere-app bedevere-app bot mentioned this issue Mar 31, 2025
Merged
@python python deleted a comment from hasanisaeed Mar 31, 2025
markshannon added a commit that referenced this issue Apr 2, 2025
@markshannon
GH-131498: Cases generator: Parse down to C statement level. (GH-131948)
ad053d8 
* Parse down to statement level in the cases generator

* Add handling for #if macros, treating them much like normal ifs.
@bedevere-app bedevere-app bot mentioned this issue Apr 4, 2025
Merged
markshannon added a commit that referenced this issue Apr 4, 2025
@markshannon
GH-131498: Cases generator: manage stacks automatically (GH-132074)
7099c75
picnixz pushed a commit to picnixz/cpython that referenced this issue Apr 5, 2025
@markshannon @picnixz
pythonGH-131498: Cases generator: manage stacks automatically (python…
0b437c4 
…GH-132074)
@bedevere-app bedevere-app bot mentioned this issue Apr 14, 2025
Merged
markshannon added a commit that referenced this issue Apr 14, 2025
@markshannon
GH-131498: Cases generator: Allow input and 'peek' variables to be mo…
844596c 
…dified (GH-132506)
seehwan pushed a commit to seehwan/cpython that referenced this issue Apr 16, 2025
@markshannon @seehwan80
pythonGH-131498: Remove conditional stack effects (pythonGH-131499)
475c7a7 
* Adds some missing #includes
seehwan pushed a commit to seehwan/cpython that referenced this issue Apr 16, 2025
@markshannon @seehwan80
pythonGH-131498: Another refactoring of the code generator (pythonGH-…
806dc49 
…131827)

* Rename 'defined' attribute to 'in_local' to more accurately reflect how it is used

* Make death of variables explicit even for array variables.

* Convert in_memory from boolean to stack offset

* Don't apply liveness analyis to optimizer generated code

* Add 'out' parameter to stack.pop
seehwan pushed a commit to seehwan/cpython that referenced this issue Apr 16, 2025
@markshannon @seehwan80
pythonGH-131498: Cases generator: Parse down to C statement level. (p…
3a447e5 
…ythonGH-131948)

* Parse down to statement level in the cases generator

* Add handling for #if macros, treating them much like normal ifs.
seehwan pushed a commit to seehwan/cpython that referenced this issue Apr 16, 2025
@markshannon @seehwan80
pythonGH-131498: Cases generator: manage stacks automatically (python…
8b7160f 
…GH-132074)
@bedevere-app bedevere-app bot mentioned this issue Apr 16, 2025
Merged
brandtbucher added a commit that referenced this issue Apr 18, 2025
@brandtbucher
GH-131498: Replace single-element arrays with scalars in bytecodes.c (G…
40ae889 
…H-132615)
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