[pypy-dev] stackless patch

Christian Tismer tismer at stackless.com
Tue Feb 21 08:22:15 CET 2006


Hi Eric,

using your nice patch, I expected both a speed increase and a size
decrease. The latter did not happen, because the exception is
tested twice.

#define StacklessUnwindAndRPyExceptionHandling(unwind_label, 
resume_label, exception_label) \
             if (RPyExceptionOccurred()) {   \
                 if (slp_frame_stack_bottom) \
                     goto unwind_label;      \
             resume_label:                   \
                 if (RPyExceptionOccurred()) \
                     FAIL(exception_label);  \
             }

Just out of curiosity: does the code shrink if we do this? :

#define StacklessUnwindAndRPyExceptionHandling(unwind_label, 
resume_label, exception_label) \
             resume_label:                   \
             if (RPyExceptionOccurred()) {   \
                 if (slp_frame_stack_bottom) \
                     goto unwind_label;      \
                 FAIL(exception_label);  \
             }

Maybe this is slightly less machine code and not slower in the
common case. Is it correct, btw? :-)

ciao - chris
-- 
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