43 lines
1.3 KiB
Nim
43 lines
1.3 KiB
Nim
# Stint
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# Copyright 2018 Status Research & Development GmbH
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# Licensed under either of
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#
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# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
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# * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
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#
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# at your option. This file may not be copied, modified, or distributed except according to those terms.
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import ./datatypes, typetraits
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func initUintImpl*[InType, OutType](x: InType, _: typedesc[OutType]): OutType {.inline.} =
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const
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size_in = getSize(x)
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size_out = getSize(result)
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static:
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assert size_out >= size_in, "The result type size (" & $size_out &
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" for " & $OutType.name &
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") should be equal or bigger than the input type size (" & $size_in &
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" for " & $InType.name & ")."
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when OutType is SomeUnsignedInt:
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result = x.OutType
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elif size_in == size_out:
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result = cast[type result](x)
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else:
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result.lo = initUintImpl(x, type result.lo)
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func zero*[T: BaseUint](_: typedesc[T]): T {.inline.}=
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discard
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func one*[T: BaseUint or IntImpl](_: typedesc[T]): T {.inline.}=
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when T is SomeInteger:
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result = T(1)
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else:
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let r_ptr = cast[ptr array[getSize(result) div 8, byte]](result.addr)
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when system.cpuEndian == littleEndian:
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r_ptr[0] = 1
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else:
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r_ptr[r_ptr[].len - 1] = 1
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