constantine/tests/math/t_bigints_mul_vs_gmp.nim

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Nim

# Constantine
# Copyright (c) 2018-2019 Status Research & Development GmbH
# Copyright (c) 2020-Present Mamy André-Ratsimbazafy
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
import
# Standard library
std/[random, macros, times, strutils],
# Third-party
gmp, stew/byteutils,
# Internal
../../constantine/math/io/io_bigints,
../../constantine/math/arithmetic,
../../constantine/platforms/abstractions,
# Test utilities
../../helpers/prng_unsafe
echo "\n------------------------------------------------------\n"
# We test up to 1024-bit, more is really slow
var bitSizeRNG {.compileTime.} = initRand(1234)
macro testRandomModSizes(numSizes: static int, rBits, aBits, bBits, body: untyped): untyped =
## Generate `numSizes` random bit sizes known at compile-time to test against GMP
## for A mod M
result = newStmtList()
for _ in 0 ..< numSizes:
let aBitsVal = bitSizeRNG.rand(126 .. 2048)
let bBitsVal = bitSizeRNG.rand(126 .. 2048)
let rBitsVal = bitSizeRNG.rand(62 .. 4096+128)
result.add quote do:
block:
const `aBits` = `aBitsVal`
const `bBits` = `bBitsVal`
const `rBits` = `rBitsVal`
block:
`body`
const # https://gmplib.org/manual/Integer-Import-and-Export.html
GMP_WordLittleEndian {.used.} = -1'i32
GMP_WordNativeEndian {.used.} = 0'i32
GMP_WordBigEndian {.used.} = 1'i32
GMP_MostSignificantWordFirst = 1'i32
GMP_LeastSignificantWordFirst {.used.} = -1'i32
proc main() =
var rng: RngState
let seed = uint32(getTime().toUnix() and (1'i64 shl 32 - 1)) # unixTime mod 2^32
rng.seed(seed)
echo "\n------------------------------------------------------\n"
echo "test_bigints_mod_vs_gmp xoshiro512** seed: ", seed
var r, a, b: mpz_t
mpz_init(r)
mpz_init(a)
mpz_init(b)
testRandomModSizes(12, rBits, aBits, bBits):
# echo "--------------------------------------------------------------------------------"
echo "Testing: random mul r (", align($rBits, 4), "-bit) <- a (", align($aBits, 4), "-bit) * b (", align($bBits, 4), "-bit) (full mul bits: ", align($(aBits+bBits), 4), "), r large enough? ", rBits >= aBits+bBits
# Build the bigints
let aTest = rng.random_unsafe(BigInt[aBits])
var bTest = rng.random_unsafe(BigInt[bBits])
#########################################################
# Conversion to GMP
const aLen = (aBits + 7) div 8
const bLen = (bBits + 7) div 8
var aBuf: array[aLen, byte]
var bBuf: array[bLen, byte]
aBuf.marshal(aTest, bigEndian)
bBuf.marshal(bTest, bigEndian)
mpz_import(a, aLen, GMP_MostSignificantWordFirst, 1, GMP_WordNativeEndian, 0, aBuf[0].addr)
mpz_import(b, bLen, GMP_MostSignificantWordFirst, 1, GMP_WordNativeEndian, 0, bBuf[0].addr)
#########################################################
# Multiplication
mpz_mul(r, a, b)
# If a*b overflow the result size we truncate
const numWords = wordsRequired(rBits)
when numWords < wordsRequired(aBits+bBits):
echo " truncating from ", wordsRequired(aBits+bBits), " words to ", numWords, " (2^", WordBitwidth * numWords, ")"
r.mpz_tdiv_r_2exp(r, WordBitwidth * numWords)
# Constantine
var rTest: BigInt[rBits]
rTest.prod(aTest, bTest)
#########################################################
# Check
{.push warnings: off.} # deprecated csize
var aW, bW, rW: csize # Word written by GMP
{.pop.}
const rLen = numWords * WordBitWidth
var rGMP: array[rLen, byte]
discard mpz_export(rGMP[0].addr, rW.addr, GMP_MostSignificantWordFirst, 1, GMP_WordNativeEndian, 0, r)
var rConstantine: array[rLen, byte]
marshal(rConstantine, rTest, bigEndian)
# Note: in bigEndian, GMP aligns left while constantine aligns right
doAssert rGMP.toOpenArray(0, rW-1) == rConstantine.toOpenArray(rLen-rW, rLen-1), block:
# Reexport as bigEndian for debugging
discard mpz_export(aBuf[0].addr, aW.addr, GMP_MostSignificantWordFirst, 1, GMP_WordNativeEndian, 0, a)
discard mpz_export(bBuf[0].addr, bW.addr, GMP_MostSignificantWordFirst, 1, GMP_WordNativeEndian, 0, b)
"\nMultiplication with operands\n" &
" a (" & align($aBits, 4) & "-bit): " & aBuf.toHex & "\n" &
" b (" & align($bBits, 4) & "-bit): " & bBuf.toHex & "\n" &
"into r of size " & align($rBits, 4) & "-bit failed:" & "\n" &
" GMP: " & rGMP.toHex() & "\n" &
" Constantine: " & rConstantine.toHex() & "\n" &
"(Note that GMP aligns bytes left while constantine aligns bytes right)"
main()