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6c1c8f51b3
* IC: renamed to_packed_ast module to ic module * IC: don't store the --forceBuild flag, makes it easier to test * IC: enable hello world test * Codegen: refactorings for IC; changed the name mangling algorithm * fixed the HCR regressions * life is too short for HCR * tconvexhull is now allowed to use deepCopy * IC exposed a stdlib bug, required a refactoring * codegen: code cleanups * IC: even if a module is outdated, its dependencies might come from disk * IC: progress * IC: better name mangling, module IDs are not stable * IC: another refactoring helping with --ic:on --gc:arc * disable arraymancer on Windows for the time being * disable arraymancer altogether * IC: make basic test work with 'nim cpp' * IC: progress on --ic:on --gc:arc * wip; name mangling for type info
26 lines
1.0 KiB
Nim
26 lines
1.0 KiB
Nim
#
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#
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# Nim's Runtime Library
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# (c) Copyright 2012 Andreas Rumpf
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#
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# See the file "copying.txt", included in this
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# distribution, for details about the copyright.
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#
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## Contains the used algorithms for counting bits.
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proc countBits32*(n: uint32): int {.compilerproc.} =
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# generic formula is from: https://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
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var v = uint32(n)
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v = v - ((v shr 1'u32) and 0x55555555'u32)
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v = (v and 0x33333333'u32) + ((v shr 2'u32) and 0x33333333'u32)
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result = (((v + (v shr 4'u32) and 0xF0F0F0F'u32) * 0x1010101'u32) shr 24'u32).int
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proc countBits64*(n: uint64): int {.compilerproc, inline.} =
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# generic formula is from: https://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
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var v = uint64(n)
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v = v - ((v shr 1'u64) and 0x5555555555555555'u64)
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v = (v and 0x3333333333333333'u64) + ((v shr 2'u64) and 0x3333333333333333'u64)
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v = (v + (v shr 4'u64) and 0x0F0F0F0F0F0F0F0F'u64)
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result = ((v * 0x0101010101010101'u64) shr 56'u64).int
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