refactor(cmdexpand): prefer memmove over strmove #29235
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Again, why? |
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It avoids the string being scanned for its length. A micro-op basically. |
To avoid calling strlen for every STRMOVE in a loop since STRMOVE(dst, src) expands to memmove(dst, src, strlen(src) + 1) because here we know strlen(src) and that it is constant. |
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I'd be more excited about this if it prevented overflow and would shut up some code scanning tools. |
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Calling memmove in a loop is already quadratic. This changes it from 2 * n^2 operations to n^2. |
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When the length of the source string is known, use memmove over strmove to avoid the strlen.