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| author | Victor Stinner <vstinner@python.org> | 2021-09-17 20:46:38 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-09-17 20:46:38 (GMT) |
| commit | e4044e9f893350b4623677c048d33414a77edf55 (patch) | |
| tree | 7a0aec99a457847f8912bc3c675a709eacf7bd10 | |
| parent | 51ebb7f4f5e9bdcf8279a1d91be9569706f6bead (diff) | |
| download | cpython-e4044e9f893350b4623677c048d33414a77edf55.zip cpython-e4044e9f893350b4623677c048d33414a77edf55.tar.gz cpython-e4044e9f893350b4623677c048d33414a77edf55.tar.bz2 | |
bpo-45116: Py_DEBUG ignores Py_ALWAYS_INLINE (GH-28419)
If the Py_DEBUG macro is defined, the Py_ALWAYS_INLINE macro does
nothing.
| -rw-r--r-- | Doc/c-api/intro.rst | 3 | ||||
| -rw-r--r-- | Include/pyport.h | 11 |
2 files changed, 13 insertions, 1 deletions
diff --git a/Doc/c-api/intro.rst b/Doc/c-api/intro.rst index aac28b1..3e7890c 100644 --- a/Doc/c-api/intro.rst +++ b/Doc/c-api/intro.rst @@ -124,6 +124,9 @@ complete listing. worse performances (due to increased code size for example). The compiler is usually smarter than the developer for the cost/benefit analysis. + If Python is :ref:`built in debug mode <debug-build>` (if the ``Py_DEBUG`` + macro is defined), the :c:macro:`Py_ALWAYS_INLINE` macro does nothing. + It must be specified before the function return type. Usage:: static inline Py_ALWAYS_INLINE int random(void) { return 4; } diff --git a/Include/pyport.h b/Include/pyport.h index af7fbe7..d27d083 100644 --- a/Include/pyport.h +++ b/Include/pyport.h @@ -568,10 +568,19 @@ extern "C" { // worse performances (due to increased code size for example). The compiler is // usually smarter than the developer for the cost/benefit analysis. // +// If Python is built in debug mode (if the Py_DEBUG macro is defined), the +// Py_ALWAYS_INLINE macro does nothing. +// // It must be specified before the function return type. Usage: // // static inline Py_ALWAYS_INLINE int random(void) { return 4; } -#if defined(__GNUC__) || defined(__clang__) || defined(__INTEL_COMPILER) +#if defined(Py_DEBUG) + // If Python is built in debug mode, usually compiler optimizations are + // disabled. In this case, Py_ALWAYS_INLINE can increase a lot the stack + // memory usage. For example, forcing inlining using gcc -O0 increases the + // stack usage from 6 KB to 15 KB per Python function call. +# define Py_ALWAYS_INLINE +#elif defined(__GNUC__) || defined(__clang__) || defined(__INTEL_COMPILER) # define Py_ALWAYS_INLINE __attribute__((always_inline)) #elif defined(_MSC_VER) # define Py_ALWAYS_INLINE __forceinline |