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| author | Eric Snow <ericsnowcurrently@gmail.com> | 2021-06-15 22:35:25 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-06-15 22:35:25 (GMT) |
| commit | ac38a9f2dfbba95f5d4338eb11a0221d38ef9328 (patch) | |
| tree | cbe976854afe2fc55df27e5134abc9cdc727c601 /Misc | |
| parent | 1d10bf0bb9409a406c56b0de8870df998637fd0f (diff) | |
| download | cpython-ac38a9f2dfbba95f5d4338eb11a0221d38ef9328.zip cpython-ac38a9f2dfbba95f5d4338eb11a0221d38ef9328.tar.gz cpython-ac38a9f2dfbba95f5d4338eb11a0221d38ef9328.tar.bz2 | |
bpo-43693: Eliminate unused "fast locals". (gh-26587)
Currently, if an arg value escapes (into the closure for an inner function) we end up allocating two indices in the fast locals even though only one gets used. Additionally, using the lower index would be better in some cases, such as with no-arg `super()`. To address this, we update the compiler to fix the offsets so each variable only gets one "fast local". As a consequence, now some cell offsets are interspersed with the locals (only when an arg escapes to an inner function).
https://bugs.python.org/issue43693
Diffstat (limited to 'Misc')
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2021-06-07-15-13-44.bpo-43693.c_zDeY.rst | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-06-07-15-13-44.bpo-43693.c_zDeY.rst b/Misc/NEWS.d/next/Core and Builtins/2021-06-07-15-13-44.bpo-43693.c_zDeY.rst new file mode 100644 index 0000000..c3db810 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2021-06-07-15-13-44.bpo-43693.c_zDeY.rst @@ -0,0 +1,4 @@ +Computation of the offsets of cell variables is done in the compiler instead +of at runtime. This reduces the overhead of handling cell and free +variables, especially in the case where a variable is both an argument and +cell variable. |