Optimize do_string_sub() by skipping vim_regsub() for literal substitutions#19707
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mattn wants to merge 1 commit intovim:masterfrom
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Optimize do_string_sub() by skipping vim_regsub() for literal substitutions#19707mattn wants to merge 1 commit intovim:masterfrom
mattn wants to merge 1 commit intovim:masterfrom
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When the substitution string contains no special characters ('&' or '\'),
use mch_memmove() directly instead of calling vim_regsub(). This avoids
unnecessary regex substitution processing for plain string replacements.
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Hm, I think you need to also consider the |
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vim_regsub()indo_string_sub()when the substitution string contains no special characters (&or\). In that case, usemch_memmove()directly instead of callingvim_regsub()twice (once for length calculation, once for copy). The newsubstitute_literal_copy()function detects literal substitution strings upfront.Benchmark with 100,000
substitute()calls (average of 3 runs):'b'→'XYZ')'b'→'')'う'→'カキク')repeat('abcdefg',100),'cd'→'XXXX')\0(not optimized)Short strings see modest improvement. Long strings with many matches get ~2x speedup. Substitutions using backreferences still go through
vim_regsub()and are unaffected.