101 lines
2.8 KiB
Nim
101 lines
2.8 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 ../stint, unittest
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suite "Testing unsigned int multiplication implementation":
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test "Multiplication with result fitting in low half":
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let a = 10000.stuint(64)
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let b = 10000.stuint(64)
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check: cast[uint64](a*b) == 100_000_000'u64 # need 27-bits
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test "Multiplication with result overflowing low half":
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let a = 1_000_000.stuint(64)
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let b = 1_000_000.stuint(64)
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check: cast[uint64](a*b) == 1_000_000_000_000'u64 # need 40 bits
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test "Full overflow is handled like native unsigned types":
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let a = 1_000_000_000.stuint(64)
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let b = 1_000_000_000.stuint(64)
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let c = 1_000.stuint(64)
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check: cast[uint64](a*b*c) == 1_000_000_000_000_000_000_000'u64 # need 70-bits
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test "Nim v1.0.2 32 bit type inference rule changed":
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let x = 9975492817.stuint(256)
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let y = 16.stuint(256)
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check x * y == 159607885072.stuint(256)
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suite "Testing unsigned int division and modulo implementation":
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test "Divmod(100, 13) returns the correct result":
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let a = 100.stuint(64)
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let b = 13.stuint(64)
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let qr = divmod(a, b)
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check: cast[uint64](qr.quot) == 7'u64
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check: cast[uint64](qr.rem) == 9'u64
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test "Divmod(2^64, 3) returns the correct result":
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let a = 1.stuint(128) shl 64
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let b = 3.stuint(128)
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let qr = divmod(a, b)
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let q = cast[UintImpl[uint64]](qr.quot)
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let r = cast[UintImpl[uint64]](qr.rem)
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check: q.lo == 6148914691236517205'u64
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check: q.hi == 0'u64
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check: r.lo == 1'u64
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check: r.hi == 0'u64
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test "Divmod(1234567891234567890, 10) returns the correct result":
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let a = cast[StUint[64]](1234567891234567890'u64)
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let b = cast[StUint[64]](10'u64)
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let qr = divmod(a, b)
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let q = cast[uint64](qr.quot)
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let r = cast[uint64](qr.rem)
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check: q == 123456789123456789'u64
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check: r == 0'u64
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suite "Testing specific failures highlighted by property-based testing":
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test "Modulo: 65696211516342324 mod 174261910798982":
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let u = 65696211516342324'u64
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let v = 174261910798982'u64
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let a = cast[Stuint[64]](u)
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let b = cast[Stuint[64]](v)
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let z = u mod v
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let tz = cast[uint64](a mod b)
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check: z == tz
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test "Modulo: 15080397990160655 mod 600432699691":
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let u = 15080397990160655'u64
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let v = 600432699691'u64
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let a = cast[Stuint[64]](u)
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let b = cast[Stuint[64]](v)
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let z = u mod v
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let tz = cast[uint64](a mod b)
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check: z == tz
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