Alexandre Vassalotti <alexan...@peadrop.com> added the comment: Antoine Pitrou wrote: > [...] count the number of indirect jump instructions in ceval.c: > > grep -E "jmp[[:space:]]\*%" ceval.s > > There should be 85 to 90 of them, roughly. If there are many less, then > the compiler has tried to optimize them by "sharing" them.
I get 86 with GCC 4.x and SUNCC. However, with GCC 3.4 I only get a single computed goto. Is there some hidden option to make GCC avoid sharing jumps? > Because otherwise the measurements these options are meant to do would > be meaningless. Ah, I see now. Maybe you should add a quick comment that mentions this. > I don't have a Sun machine to test, so I'll leave to someone else to > check and enable if they want to. I tested it and it worked, no test failures to report. Just change the macro test: #ifdef __GNUC__ && \ ... to #ifdef (__GNUC__ || __SUNPRO_C) && \ ... I attached some additional benchmarks on SunOS. So far, it seems the benefits of the proposed optimization are highly compiler-dependent. Added file: http://bugs.python.org/file12521/amd-athlon64-x2-suncc-pybench.txt _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue4753> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
