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Cherry Mui authored
Currently, a symbol's outer symbol, the "special" attribute, and whether a symbol is a generator symbol are represented as maps, and are accessed in some loops over nearly all reachable symbols. The map lookups are a bit expensive. For outer symbol, a non-trivial portion of the symbols have outer symbol set (e.g. type symbols, which we put into container symbols like "type:*"). Using a slice to access more efficiently. For the special and generator symbol attributes, use a bitmap. There are not many symbols have those attributes, so the bitmap is quite sparse. The bitmap is not too large anyway, so use it for now. If we want to further reduce memory usage we could consider some other data structure like a Bloom filter. Linking cmd/compile in external linking mode (on macOS/amd64) Symtab 12.9ms ± 9% 6.4ms ± 5% -50.08% (p=0.000 n=19+18) Dodata 64.9ms ±12% 57.1ms ±12% -11.90% (p=0.000 n=20+20) Asmb 36.7ms ±11% 32.8ms ± 9% -10.61% (p=0.000 n=20+18) Asmb2 26.6ms ±15% 21.9ms ±12% -17.75% (p=0.000 n=20+18) There is some increase of memory usage Munmap_GC 40.9M ± 1% 43.2M ± 0% +5.54% (p=0.000 n=20+19) The next CL will bring the memory usage back. Change-Id: Ie4347eb96c51f008b9284270de37fc880bb52d2c Reviewed-on: https://go-review.googlesource.com/c/go/+/487415 Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by:
Austin Clements <austin@google.com>
Cherry Mui authoredCurrently, a symbol's outer symbol, the "special" attribute, and whether a symbol is a generator symbol are represented as maps, and are accessed in some loops over nearly all reachable symbols. The map lookups are a bit expensive. For outer symbol, a non-trivial portion of the symbols have outer symbol set (e.g. type symbols, which we put into container symbols like "type:*"). Using a slice to access more efficiently. For the special and generator symbol attributes, use a bitmap. There are not many symbols have those attributes, so the bitmap is quite sparse. The bitmap is not too large anyway, so use it for now. If we want to further reduce memory usage we could consider some other data structure like a Bloom filter. Linking cmd/compile in external linking mode (on macOS/amd64) Symtab 12.9ms ± 9% 6.4ms ± 5% -50.08% (p=0.000 n=19+18) Dodata 64.9ms ±12% 57.1ms ±12% -11.90% (p=0.000 n=20+20) Asmb 36.7ms ±11% 32.8ms ± 9% -10.61% (p=0.000 n=20+18) Asmb2 26.6ms ±15% 21.9ms ±12% -17.75% (p=0.000 n=20+18) There is some increase of memory usage Munmap_GC 40.9M ± 1% 43.2M ± 0% +5.54% (p=0.000 n=20+19) The next CL will bring the memory usage back. Change-Id: Ie4347eb96c51f008b9284270de37fc880bb52d2c Reviewed-on: https://go-review.googlesource.com/c/go/+/487415 Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by:
Austin Clements <austin@google.com>
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