[libcxx-commits] [PATCH] D131395: [libc++] Implement `lexicographical_compare_three_way`

[Adrian Vogelsgesang via Phabricator via libcxx-commits]

avogelsgesang added inline comments.


================
Comment at: libcxx/include/__algorithm/lexicographical_compare_three_way.h:45-47
+    ptrdiff_t __len1    = __last1 - __first1;
+    ptrdiff_t __len2    = __last2 - __first2;
+    ptrdiff_t __min_len = std::min(__len1, __len2);
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philnik wrote:
> (Thanks to @Quuxplusone for pointing it out!) Using `ptrdiff_t` is actually a bug because it might be smaller than the largest signed integer. Probably the easiest thing to do is to use `auto` instead and replace the `std::min()` with a ternary. For `__i` you could maybe use `decltype(__min_len)`. There might be a better way to do all this, I'm not sure.
Added a benchmark now. It shows a 30% improvement with the fast path


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D131395/new/

https://reviews.llvm.org/D131395