58 lines
1.7 KiB
Nim
58 lines
1.7 KiB
Nim
# Stint
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# Copyright 2018-Present 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
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# Internal
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./datatypes,
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./primitives/addcarry_subborrow
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# Addsub
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# --------------------------------------------------------
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{.push raises: [], inline, noInit, gcsafe.}
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func sum*(r: var Stuint, a, b: Stuint) =
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## Addition for multi-precision unsigned int
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var carry = Carry(0)
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for i in 0 ..< r.limbs.len:
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addC(carry, r[i], a[i], b[i], carry)
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r.clearExtraBitsOverMSB()
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func `+=`*(a: var Stuint, b: Stuint) =
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## In-place addition for multi-precision unsigned int
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a.sum(a, b)
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func diff*(r: var Stuint, a, b: Stuint) =
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## Substraction for multi-precision unsigned int
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var borrow = Borrow(0)
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for i in 0 ..< r.limbs.len:
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subB(borrow, r[i], a[i], b[i], borrow)
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r.clearExtraBitsOverMSB()
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func `-=`*(a: var Stuint, b: Stuint) =
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## In-place substraction for multi-precision unsigned int
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a.diff(a, b)
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func inc*(a: var Stuint, w: Word = 1) =
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var carry = Carry(0)
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addC(carry, a.limbs[0], a.limbs[0], w, carry)
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for i in 1 ..< a.limbs.len:
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addC(carry, a.limbs[i], a.limbs[i], 0, carry)
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a.clearExtraBitsOverMSB()
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func sum*(r: var Stuint, a: Stuint, b: SomeUnsignedInt) =
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## Addition for multi-precision unsigned int
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## with an unsigned integer
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r = a
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r.inc(Word(b))
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func `+=`*(a: var Stuint, b: SomeUnsignedInt) =
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## In-place addition for multi-precision unsigned int
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## with an unsigned integer
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a.inc(Word(b))
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