On Fri, 28 Jun 2024, WangYuli wrote: > As you can see, regardless of the Clang or GCC version, this redundant > operation affects the generated > > assembly code. Boy, this code is horribly structured! Anyway, rather than making it yet worse with another #ifdef I'd suggest replacing both `while' loops with equivalent `for' ones with `len' being the worker variable, which will then make the code structure a little bit better and as a side effect address the missed optimisation automagically. You might also consider Herbert's suggestion to use IS_ENABLED, however in the current shape of code I find it kind of pointless anyway. Instead I think that it would make more sense to factor out the block bodies to small static inline helpers and then restructure the call sites so that IS_ENABLED controls the loops, the conditionals, and the choice between them as applicable. Maciej
