I saw no difference for between unwind's two versions with current GCC, clang, or icc with -O3: https://godbolt.org/z/n6avo5ovq https://godbolt.org/z/n6avo5ovq.

I saw no difference for between unwind's two versions with current GCC, clang, or icc with -O3: https://godbolt.org/z/n6avo5ovq https://godbolt.org/z/n6avo5ovq. Did you possibly forgot to use optimization? I was surprised though to see that icc inlined the call to strlen!