I am trying to generate loop unrolling for a lookahead guard mechanism for a recursive descent parser.
Here is the code :-
And heres what GodBolt is giving me for Clang, its using xmm, when I really want this to boil down to a 64 bit AND and a JNZ :-
GCC is giving me alright results for this :-
If someone who knows about Clang optimization can have a look at this please ?
Many thanks in advance,
Okay I think I have rationalized things a touch :-
Both come down to a TEST instruction near enough basically :-
MS Visual Studio C++ is a nightmare still though :-
Solved MS VS C++ on command line, getting simular results, although not as good as Clang or GCC.
I am now looking at proper implementation in C++, and also C.