diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -177,12 +177,21 @@ extern "C" { buffer where the result characters are written to. */ #define _PyUnicode_CONVERT_BYTES(from_type, to_type, begin, end, to) \ do { \ - const from_type *iter_; to_type *to_; \ - for (iter_ = (begin), to_ = (to_type *)(to); \ - iter_ < (end); \ - ++iter_, ++to_) { \ - *to_ = (to_type)*iter_; \ + to_type *_to = (to_type *) to; \ + const from_type *_iter = (begin); \ + const from_type *_end = (end); \ + Py_ssize_t n = (_end) - (_iter); \ + const from_type *_unrolled_end = \ + _iter + (n & ~ (Py_ssize_t) 3); \ + while (_iter < (_unrolled_end)) { \ + _to[0] = (to_type) _iter[0]; \ + _to[1] = (to_type) _iter[1]; \ + _to[2] = (to_type) _iter[2]; \ + _to[3] = (to_type) _iter[3]; \ + _iter += 4; _to += 4; \ } \ + while (_iter < (_end)) \ + *_to++ = (to_type) *_iter++; \ } while (0) /* The Unicode string has been modified: reset the hash */