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From: M. C. <mma...@gm...> - 2018-06-11 15:28:05
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Hi, The highest suggested optimization level for Valgrind seems to be `-O1`. What we are seeing is that clang runs much slower with `-O1` than gcc (~3x), even without Valgrind, and with Valgrind, the difference is considerable. To reproduce: https://github.com/m-chaturvedi/test_valgrind_slowdown I have asked the question of how can I make clang and gcc of comparable speeds on LLVM and gcc mailing lists to no avail. I was wondering if folks at Valgrind would have any suggestions about it, perhaps if there are any compiler wise difference in the highest optimization level one could use without affecting the results much? GCC: https://gcc.gnu.org/ml/gcc-help/2018-06/msg00023.html LLVM: http://lists.llvm.org/pipermail/llvm-dev/2018-May/123708.html Thanks, Mmanu Chaturvedi |