Below is the relevant snippet from pyport.h.  There are two reasons that
Py_LOCAL_INLINE doesn't actually emit the "inline" keyword (unless
compiling with MSC).  

First, "configure" does not have code to test the compiler and define
USE_INLINE if appropriate.

Second, the code undefines USE_INLINE even if defined! (oops? ;) )

The snippet is replicated with slightly different names near the top of
_sre.c.

#undef USE_INLINE /* XXX - set via configure? */

#if defined(_MSC_VER)
#if defined(PY_LOCAL_AGGRESSIVE)
/* enable more aggressive optimization for visual studio */
#pragma optimize("agtw", on)
#endif
/* ignore warnings if the compiler decides not to inline a function */
#pragma warning(disable: 4710)
/* fastest possible local call under MSVC */
#define Py_LOCAL(type) static type __fastcall
#define Py_LOCAL_INLINE(type) static __inline type __fastcall
#elif defined(USE_INLINE)
#define Py_LOCAL(type) static type
#define Py_LOCAL_INLINE(type) static inline type
#else
#define Py_LOCAL(type) static type
#define Py_LOCAL_INLINE(type) static type
#endif

Configure could call macro to define inline - cf. autoconf manuals.

Py_LOCAL_INLINE is also not used a lot. Usually, the compiler will inline small static functions by itself. Most of the time, we used #defines rather than functions when we want to inline short snippets of code.

Attached is a patch.  

The diff to configure is just what autoconf produces as a result of the diff to configure.in.

With the patch, pyconfig.h will:
- do nothing if the compiler supports the "inline" keyword
- #define inline to __inline or __inline__ if that's the compiler supports
- #define inline to nothing if the compiler doesn't support inlining

The patch also updates pyport.h and _sre.c appropriately.

I should add that the patch is against the py3k branch, since it's too late for performance improvements to land in trunk.

The patch looks ok to me.

Committed in r84379

Note: autoreconf failure caused by r84379 was fixed by r84512.

Ned, thanks for bringing that to my attention.  I might have missed it otherwise.

I had run "autoconf" but had not known to run "autoreconf", so I had missed the failure there.  *embarrassed*

Benjamin, thanks for fixing my error!