
Why does Julia use native machine integer arithmetic? - luu
http://docs.julialang.org/en/latest/manual/faq/#why-does-julia-use-native-machine-integer-arithmetic
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nostrademons
Most hardware architectures have a trap or condition set upon integer
overflow, eg. x86 has the 'jo' instruction to jump if the overflow flag is set
after an integer operation. Unfortunately, these are not exposed by C, so
there's no _portable_ way to access them, as long as you're writing the
interpreter in C. This is one of the big advantages of compiling to LLVM or
directly to the hardware; LLVM provides the llvm.*.with.overflow intrinsics to
access the overflow flag of the hardware, which lets you do bigints at
basically zero overhead.

