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5553 :: Binary resulting much larger with --opt:size?

• drkameleon (orginal) [2019-11-18T08:07:12+01:00] view original

  I've just noticed sth very weird.

  I have 2 different tasks in my nimble file. One builds the project with --opt:size and one with --opt:speed. The thing is the resulting binary with the first option is over 900KB, while with --opt:speed it get down to 600-sth(!). How is that possible?

  Nim version: 1.0.3 [MacOSX: amd64] - Compiled at 2019-11-09 (git hash: 7ea60f78b5bd90bd34c5b15e1a80d23fd41c36a8)

  command options for 'mini' build:

  
  nim c --gcc.options.speed="-O4 -Ofast -flto -march=native -fno-strict-aliasing -ffast-math -ldl" --gcc.options.linker="-flto -ldl" --clang.options.speed="-O4 -Ofast -flto -march=native -fno-strict-aliasing -ffast-math -ldl" --clang.options.linker="-flto -ldl" -d:release -d:mini -d:danger --passL:parser.a --threads:on --hints:off --opt:speed --gc:regions --path:src -o:arturo -f --nimcache:_cache --embedsrc --checks:off --overflowChecks:on src/main.nim
  Run

  command options for 'full' (speed) build:

  
  nim c --gcc.options.speed="-O4 -Ofast -flto -march=native -fno-strict-aliasing -ffast-math -ldl" --gcc.options.linker="-flto -ldl" --clang.options.speed="-O4 -Ofast -flto -march=native -fno-strict-aliasing -ffast-math -ldl" --clang.options.linker="-flto -ldl" -d:release -d:danger --passL:parser.a --threads:on --hints:off --opt:speed --gc:regions --path:src -o:arturo -f --nimcache:_cache --embedsrc --checks:off --overflowChecks:on src/main.nim
  Run

  Any ideas?

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• Araq (orginal) [2019-11-18T09:23:11+01:00] view original

  The only difference is the -d:mini flag, you don't use --opt:size.

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• drkameleon (orginal) [2019-11-18T09:31:13+01:00] view original

  Well, I am - I just miss-copypasted the command-line options. (the mini flag only thing it does is omit some part of the code in the corresponding release, for further size cuts)

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• mratsim (orginal) [2019-11-18T10:11:50+01:00] view original

  -O4 will conflict with building for size -Os

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• drkameleon (orginal) [2019-11-18T10:42:32+01:00] view original

  I don't think they are interfering. The -O4 option is only set for speed and I'm getting the exact same result (900+KB vs 600+KB) even after completely removing it.

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• mratsim (orginal) [2019-11-18T10:52:44+01:00] view original

  --opt:speed implies -O3

  --opt:size implies -Os

  passing -O4 will impli -O3

  It's either -O3 or -Os, you can't have both at the same time hence the conflict.

  Now it seems like there might still be an issue but without reproducible example it's hard to investigate. You can check with bloaty (https://github.com/google/bloaty) to have an idea if it's just text symbols that are taking space or if it's actual code for example.

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