3c38efbfe4
operator=(~) and assign(~) share similar names but, until now, have not shared the same functionality. This patch introduces the usage of QByteArray::assign() within the non-sharing assignment operator to effectively boost efficiency by reusing the available capacity. Since these assignment operators are frequently used in many places, both within Qt and non-Qt code, this patch comes with benchmarks. The preview of the benchmark results are compared with this patch and before this patch. The findings indicate a slight enhancement in performance associated with the assignment operator. Despite the results displaying only a minor improvement, progress has been made. Therefore use assign(QByteArrayView) as replacement. (x86_64-little_endian-lp64 shared (dynamic) release build (O3); by gcc 13.2.1, endeavouros ; 13th Gen Intel(R) Core(TM) i9-13900K benchmarks executed with -perf -iterations 1000000 * The last value at the EOL represent the string size. QByteArray &operator=(const char *ch) (current) 65 cycles/iter; 317 instructions/iter; 16.0 nsec/iter (5) 71.7 cycles/iter; 383 instructions/iter; 13.0 nsec/iter (10) 59.8 cycles/iter; 318 instructions/iter; 10.9 nsec/iter (20) 70.8 cycles/iter; 340 instructions/iter; 12.9 nsec/iter (50) 80.2 cycles/iter; 419 instructions/iter; 14.6 nsec/iter (100) 164.2 cycles/iter; 899 instructions/iter; 29.9 nsec/iter (500) 260.5 cycles/iter; 1522 instructions/iter; 45.6 nsec/iter (1'000) QByteArray &operator=(const char *ch) (before) 66.8 cycles/iter; 317 instructions/iter; 16.9 nsec/iter (5) 76.5 cycles/iter; 383 instructions/iter; 13.9 nsec/iter (10) 63.7 cycles/iter; 318 instructions/iter; 11.6 nsec/iter (20) 71.6 cycles/iter; 344 instructions/iter; 13.0 nsec/iter (50) 77.5 cycles/iter; 419 instructions/iter; 14.1 nsec/iter (100) 143.4 cycles/iter; 893 instructions/iter; 26.1 nsec/iter (500) 270.8 cycles/iter; 1516 instructions/iter; 48.2 nsec/iter (1'000) Task-number: QTBUG-106201 Change-Id: I0745c33f0f61f1d844a60960cc55f565320d5945 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> |
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| io | ||
| itemmodels | ||
| json | ||
| kernel | ||
| mimetypes | ||
| plugin | ||
| text | ||
| thread | ||
| time | ||
| tools | ||
| CMakeLists.txt | ||