llvm-project

f9065fce - [llvm][mustache] Avoid excessive hash lookups in EscapeStringStream (#160166)

[llvm][mustache] Avoid excessive hash lookups in EscapeStringStream (#160166) The naive char-by-char lookup performed OK, but we can skip ahead to the next match, avoiding all the extra hash lookups in the key map. Likely there is a faster method than this, but its already a 42% win in the BM_Mustache_StringRendering/Escaped benchmark, and an order of magnitude improvement for BM_Mustache_LargeOutputString. | Benchmark | Before (ns) | After (ns) | Speedup | | :--- | ---: | ---: | ---: | | `StringRendering/Escaped` | 29,440,922 | 16,583,603 | ~44% | | `LargeOutputString` | 15,139,251 | 929,891 | ~94% | | `HugeArrayIteration` | 102,148,245 | 95,943,960 | ~6% | | `PartialsRendering` | 308,330,014 | 303,556,563 | ~1.6% | Unreported benchmarks, like those for parsing, had no significant change.