This gives best performance for short strings, now that we have a h-advance cache as well.
The en-words benchmark in particular, now ot-font is faster than ft.
Second to last line is of interest:
Before:
-----------------------------------------------------------------------------------------------------
Benchmark Time CPU Iterations
-----------------------------------------------------------------------------------------------------
BM_Shape/en-words.txt/Roboto-Regular.ttf/hb 29.8 ms 29.8 ms 23
BM_Shape/en-words.txt/Roboto-Regular.ttf/ft 30.4 ms 30.4 ms 23
BM_Shape/en-words.txt/SourceSerifVariable-Roman.ttf/hb 16.3 ms 16.3 ms 43
BM_Shape/en-words.txt/SourceSerifVariable-Roman.ttf/ft 16.5 ms 16.5 ms 42
BM_Shape/en-words.txt/SourceSerifVariable-Roman.ttf/var/hb 18.0 ms 18.0 ms 39
BM_Shape/en-words.txt/SourceSerifVariable-Roman.ttf/var/ft 17.8 ms 17.8 ms 39
After:
behdad@Behdads-MacBook-Pro harfbuzz % ninja -Cbuild && build/perf/benchmark-shape --benchmark_filter=en-words
-----------------------------------------------------------------------------------------------------
Benchmark Time CPU Iterations
-----------------------------------------------------------------------------------------------------
BM_Shape/en-words.txt/Roboto-Regular.ttf/hb 30.0 ms 30.0 ms 23
BM_Shape/en-words.txt/Roboto-Regular.ttf/ft 30.3 ms 30.3 ms 23
BM_Shape/en-words.txt/SourceSerifVariable-Roman.ttf/hb 16.3 ms 16.3 ms 43
BM_Shape/en-words.txt/SourceSerifVariable-Roman.ttf/ft 16.4 ms 16.4 ms 43
BM_Shape/en-words.txt/SourceSerifVariable-Roman.ttf/var/hb 17.6 ms 17.6 ms 40
BM_Shape/en-words.txt/SourceSerifVariable-Roman.ttf/var/ft 17.8 ms 17.8 ms 39
If compiler doesn't inline StructAtOffset, this was an error since we
only disable cast-align at call-site. So, move the cast out.
../src/hb-machinery.hh: In instantiation of 'const Type& StructAtOffset(const void*, unsigned int) [with Type = unsigned int]':
../src/hb-font.cc:146:85: required from here
../src/hb-machinery.hh:63:12: error: cast from 'const char*' to 'const unsigned int*' increases required alignment of target type [-Werror=cast-align]
{ return * reinterpret_cast<const Type*> ((const char *) P + offset); }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/hb-machinery.hh: In instantiation of 'Type& StructAtOffset(void*, unsigned int) [with Type = unsigned int]':
../src/hb-font.cc:147:79: required from here
../src/hb-machinery.hh:66:12: error: cast from 'char*' to 'unsigned int*' increases required alignment of target type [-Werror=cast-align]
{ return * reinterpret_cast<Type*> ((char *) P + offset); }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Behdad Esfahbod
Nathan Willis
blueshade7
Ebrahim Byagowi
Evgeniy Reizner