Re:Engineering Faster Sorters for Small Sets of Items
by thedance on Friday February 14, 2020 @01:14AM
(#22324344)
The most interesting thing to me is "the compiler reduces
its optimizations with increasing compilation effort, when compiling only a single source file." Is this GCC-specific, or does it also hold for clang? And can it be tuned away?
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Re:Engineering Faster Sorters for Small Sets of Items
by jdoerfert on Friday February 14, 2020 @02:42AM
(#22324729)
Clang will not "reduce compilation effort" and I do not believe GCC does that. There are heuristics that look at things like function size but I don't think that is what they mean. Generally speaking, translation units are independent if you do not run link-time-optimizations (LTO) and optimizations follow a (basically) predetermined order which might be influence by the input but not by the amount of work done.
Re:Engineering Faster Sorters for Small Sets of Items
by thedance on Friday February 14, 2020 @11:40AM
(#22327944)
I’ve never heard of or experienced gcc using some kind of cost model for compilation time, either. With all these huge protobuf-generated files you’d think I would have noticed if it existed.