This commit is contained in:
gingerBill
2021-08-17 19:54:17 +01:00
6 changed files with 266 additions and 27 deletions

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@@ -1,8 +1,9 @@
@echo off
:odin run . -vet
:odin run . -vet -o:speed -no-bounds-check
: -o:size
:odin build . -build-mode:shared -show-timings -o:minimal -no-bounds-check -define:MATH_BIG_EXE=false && python test.py -fast-tests
:odin build . -build-mode:shared -show-timings -o:size -no-bounds-check -define:MATH_BIG_EXE=false && python test.py -fast-tests
:odin build . -build-mode:shared -show-timings -o:size -define:MATH_BIG_EXE=false && python test.py -fast-tests
odin build . -build-mode:shared -show-timings -o:speed -no-bounds-check -define:MATH_BIG_EXE=false && python test.py -fast-tests
odin build . -build-mode:shared -show-timings -o:speed -no-bounds-check -define:MATH_BIG_EXE=false && python test.py
: -fast-tests
:odin build . -build-mode:shared -show-timings -o:speed -define:MATH_BIG_EXE=false && python test.py -fast-tests

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@@ -206,16 +206,18 @@ demo :: proc() {
a, b, c, d, e, f := &Int{}, &Int{}, &Int{}, &Int{}, &Int{}, &Int{};
defer destroy(a, b, c, d, e, f);
atoi(a, "12980742146337069150589594264770969721", 10);
atoi(a, "615037959146039477924633848896619112832171971562900618409305032006863881436080", 10);
print("a: ", a, 10, true, true, true);
atoi(b, "4611686018427387904", 10);
atoi(b, "378271691190525325893712245607881659587045836991909505715443874842659307597325888631898626653926188084180707310543535657996185416604973577488563643125766400", 10);
print("b: ", b, 10, true, true, true);
if err := internal_divmod(c, d, a, b); err != nil {
fmt.printf("Error: %v\n", err);
}
print("c: ", c);
print("c: ", d);
factorial(c, 10_000);
// 120CCAA2076ADF69F75A97695E6C1C2A4E6F377DF92226E43B
cs, _ := itoa(c, 16);
defer delete(cs);
print("c: ", c, 10, true, true, true);
}
main :: proc() {

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@@ -432,18 +432,16 @@ int_init_multi :: proc(integers: ..^Int, allocator := context.allocator) -> (err
init_multi :: proc { int_init_multi, };
copy_digits :: proc(dest, src: ^Int, digits: int, allocator := context.allocator) -> (err: Error) {
copy_digits :: proc(dest, src: ^Int, digits: int, offset := int(0), allocator := context.allocator) -> (err: Error) {
context.allocator = allocator;
digits := digits;
/*
Check that `src` is usable and `dest` isn't immutable.
*/
assert_if_nil(dest, src);
#force_inline internal_clear_if_uninitialized(src) or_return;
digits = min(digits, len(src.digit), len(dest.digit));
return #force_inline internal_copy_digits(dest, src, digits);
return #force_inline internal_copy_digits(dest, src, digits, offset);
}
/*

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@@ -36,8 +36,6 @@ import "core:mem"
import "core:intrinsics"
import rnd "core:math/rand"
import "core:fmt"
/*
Low-level addition, unsigned. Handbook of Applied Cryptography, algorithm 14.7.
@@ -651,7 +649,6 @@ internal_int_mul :: proc(dest, src, multiplier: ^Int, allocator := context.alloc
Fast comba?
*/
err = #force_inline _private_int_sqr_comba(dest, src);
//err = #force_inline _private_int_sqr(dest, src);
} else {
err = #force_inline _private_int_sqr(dest, src);
}
@@ -678,9 +675,13 @@ internal_int_mul :: proc(dest, src, multiplier: ^Int, allocator := context.alloc
max_used >= 2 * min_used {
// err = s_mp_mul_balance(a,b,c);
} else if false && min_used >= MUL_TOOM_CUTOFF {
// err = s_mp_mul_toom(a, b, c);
} else if false && min_used >= MUL_KARATSUBA_CUTOFF {
// err = s_mp_mul_karatsuba(a, b, c);
/*
Toom path commented out until it no longer fails Factorial 10k or 100k,
as reveaved in the long test.
*/
err = #force_inline _private_int_mul_toom(dest, src, multiplier);
} else if min_used >= MUL_KARATSUBA_CUTOFF {
err = #force_inline _private_int_mul_karatsuba(dest, src, multiplier);
} else if digits < _WARRAY && min_used <= _MAX_COMBA {
/*
Can we use the fast multiplier?
@@ -1628,16 +1629,13 @@ internal_int_set_from_integer :: proc(dest: ^Int, src: $T, minimize := false, al
internal_set :: proc { internal_int_set_from_integer, internal_int_copy };
internal_copy_digits :: #force_inline proc(dest, src: ^Int, digits: int) -> (err: Error) {
internal_copy_digits :: #force_inline proc(dest, src: ^Int, digits: int, offset := int(0)) -> (err: Error) {
#force_inline internal_error_if_immutable(dest) or_return;
/*
If dest == src, do nothing
*/
if (dest == src) { return nil; }
#force_inline mem.copy_non_overlapping(&dest.digit[0], &src.digit[0], size_of(DIGIT) * digits);
return nil;
return #force_inline _private_copy_digits(dest, src, digits, offset);
}
/*

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@@ -89,6 +89,245 @@ _private_int_mul :: proc(dest, a, b: ^Int, digits: int, allocator := context.all
return internal_clamp(dest);
}
/*
Multiplication using the Toom-Cook 3-way algorithm.
Much more complicated than Karatsuba but has a lower asymptotic running time of O(N**1.464).
This algorithm is only particularly useful on VERY large inputs.
(We're talking 1000s of digits here...).
This file contains code from J. Arndt's book "Matters Computational"
and the accompanying FXT-library with permission of the author.
Setup from:
Chung, Jaewook, and M. Anwar Hasan. "Asymmetric squaring formulae."
18th IEEE Symposium on Computer Arithmetic (ARITH'07). IEEE, 2007.
The interpolation from above needed one temporary variable more than the interpolation here:
Bodrato, Marco, and Alberto Zanoni. "What about Toom-Cook matrices optimality."
Centro Vito Volterra Universita di Roma Tor Vergata (2006)
*/
_private_int_mul_toom :: proc(dest, a, b: ^Int, allocator := context.allocator) -> (err: Error) {
context.allocator = allocator;
S1, S2, T1, a0, a1, a2, b0, b1, b2 := &Int{}, &Int{}, &Int{}, &Int{}, &Int{}, &Int{}, &Int{}, &Int{}, &Int{};
defer destroy(S1, S2, T1, a0, a1, a2, b0, b1, b2);
/*
Init temps.
*/
internal_init_multi(S1, S2, T1) or_return;
/*
B
*/
B := min(a.used, b.used) / 3;
/*
a = a2 * x^2 + a1 * x + a0;
*/
internal_grow(a0, B) or_return;
internal_grow(a1, B) or_return;
internal_grow(a2, a.used - 2 * B) or_return;
a0.used, a1.used = B, B;
a2.used = a.used - 2 * B;
internal_copy_digits(a0, a, a0.used) or_return;
internal_copy_digits(a1, a, a1.used, B) or_return;
internal_copy_digits(a2, a, a2.used, 2 * B) or_return;
internal_clamp(a0);
internal_clamp(a1);
internal_clamp(a2);
/*
b = b2 * x^2 + b1 * x + b0;
*/
internal_grow(b0, B) or_return;
internal_grow(b1, B) or_return;
internal_grow(b2, b.used - 2 * B) or_return;
b0.used, b1.used = B, B;
b2.used = b.used - 2 * B;
internal_copy_digits(b0, b, b0.used) or_return;
internal_copy_digits(b1, b, b1.used, B) or_return;
internal_copy_digits(b2, b, b2.used, 2 * B) or_return;
internal_clamp(b0);
internal_clamp(b1);
internal_clamp(b2);
/*
\\ S1 = (a2+a1+a0) * (b2+b1+b0);
*/
internal_add(T1, a2, a1) or_return; /* T1 = a2 + a1; */
internal_add(S2, T1, a0) or_return; /* S2 = T1 + a0; */
internal_add(dest, b2, b1) or_return; /* dest = b2 + b1; */
internal_add(S1, dest, b0) or_return; /* S1 = c + b0; */
internal_mul(S1, S1, S2) or_return; /* S1 = S1 * S2; */
/*
\\S2 = (4*a2+2*a1+a0) * (4*b2+2*b1+b0);
*/
internal_add(T1, T1, a2) or_return; /* T1 = T1 + a2; */
internal_int_shl1(T1, T1) or_return; /* T1 = T1 << 1; */
internal_add(T1, T1, a0) or_return; /* T1 = T1 + a0; */
internal_add(dest, dest, b2) or_return; /* c = c + b2; */
internal_int_shl1(dest, dest) or_return; /* c = c << 1; */
internal_add(dest, dest, b0) or_return; /* c = c + b0; */
internal_mul(S2, T1, dest) or_return; /* S2 = T1 * c; */
/*
\\S3 = (a2-a1+a0) * (b2-b1+b0);
*/
internal_sub(a1, a2, a1) or_return; /* a1 = a2 - a1; */
internal_add(a1, a1, a0) or_return; /* a1 = a1 + a0; */
internal_sub(b1, b2, b1) or_return; /* b1 = b2 - b1; */
internal_add(b1, b1, b0) or_return; /* b1 = b1 + b0; */
internal_mul(a1, a1, b1) or_return; /* a1 = a1 * b1; */
internal_mul(b1, a2, b2) or_return; /* b1 = a2 * b2; */
/*
\\S2 = (S2 - S3) / 3;
*/
internal_sub(S2, S2, a1) or_return; /* S2 = S2 - a1; */
_private_int_div_3(S2, S2) or_return; /* S2 = S2 / 3; \\ this is an exact division */
internal_sub(a1, S1, a1) or_return; /* a1 = S1 - a1; */
internal_int_shr1(a1, a1) or_return; /* a1 = a1 >> 1; */
internal_mul(a0, a0, b0) or_return; /* a0 = a0 * b0; */
internal_sub(S1, S1, a0) or_return; /* S1 = S1 - a0; */
internal_sub(S2, S2, S1) or_return; /* S2 = S2 - S1; */
internal_int_shr1(S2, S2) or_return; /* S2 = S2 >> 1; */
internal_sub(S1, S1, a1) or_return; /* S1 = S1 - a1; */
internal_sub(S1, S1, b1) or_return; /* S1 = S1 - b1; */
internal_int_shl1(T1, b1) or_return; /* T1 = b1 << 1; */
internal_sub(S2, S2, T1) or_return; /* S2 = S2 - T1; */
internal_sub(a1, a1, S2) or_return; /* a1 = a1 - S2; */
/*
P = b1*x^4+ S2*x^3+ S1*x^2+ a1*x + a0;
*/
internal_shl_digit(b1, 4 * B) or_return;
internal_shl_digit(S2, 3 * B) or_return;
internal_add(b1, b1, S2) or_return;
internal_shl_digit(S1, 2 * B) or_return;
internal_add(b1, b1, S1) or_return;
internal_shl_digit(a1, 1 * B) or_return;
internal_add(b1, b1, a1) or_return;
internal_add(dest, b1, a0) or_return;
/*
a * b - P
*/
return nil;
}
/*
product = |a| * |b| using Karatsuba Multiplication using three half size multiplications.
Let `B` represent the radix [e.g. 2**_DIGIT_BITS] and let `n` represent
half of the number of digits in the min(a,b)
`a` = `a1` * `B`**`n` + `a0`
`b` = `b`1 * `B`**`n` + `b0`
Then, a * b => 1b1 * B**2n + ((a1 + a0)(b1 + b0) - (a0b0 + a1b1)) * B + a0b0
Note that a1b1 and a0b0 are used twice and only need to be computed once.
So in total three half size (half # of digit) multiplications are performed,
a0b0, a1b1 and (a1+b1)(a0+b0)
Note that a multiplication of half the digits requires 1/4th the number of
single precision multiplications, so in total after one call 25% of the
single precision multiplications are saved.
Note also that the call to `internal_mul` can end up back in this function
if the a0, a1, b0, or b1 are above the threshold.
This is known as divide-and-conquer and leads to the famous O(N**lg(3)) or O(N**1.584)
work which is asymptopically lower than the standard O(N**2) that the
baseline/comba methods use. Generally though, the overhead of this method doesn't pay off
until a certain size is reached, of around 80 used DIGITs.
*/
_private_int_mul_karatsuba :: proc(dest, a, b: ^Int, allocator := context.allocator) -> (err: Error) {
context.allocator = allocator;
x0, x1, y0, y1, t1, x0y0, x1y1 := &Int{}, &Int{}, &Int{}, &Int{}, &Int{}, &Int{}, &Int{};
defer destroy(x0, x1, y0, y1, t1, x0y0, x1y1);
/*
min # of digits, divided by two.
*/
B := min(a.used, b.used) >> 1;
/*
Init all the temps.
*/
internal_grow(x0, B) or_return;
internal_grow(x1, a.used - B) or_return;
internal_grow(y0, B) or_return;
internal_grow(y1, b.used - B) or_return;
internal_grow(t1, B * 2) or_return;
internal_grow(x0y0, B * 2) or_return;
internal_grow(x1y1, B * 2) or_return;
/*
Now shift the digits.
*/
x0.used, y0.used = B, B;
x1.used = a.used - B;
y1.used = b.used - B;
/*
We copy the digits directly instead of using higher level functions
since we also need to shift the digits.
*/
internal_copy_digits(x0, a, x0.used);
internal_copy_digits(y0, b, y0.used);
internal_copy_digits(x1, a, x1.used, B);
internal_copy_digits(y1, b, y1.used, B);
/*
Only need to clamp the lower words since by definition the
upper words x1/y1 must have a known number of digits.
*/
clamp(x0);
clamp(y0);
/*
Now calc the products x0y0 and x1y1,
after this x0 is no longer required, free temp [x0==t2]!
*/
internal_mul(x0y0, x0, y0) or_return; /* x0y0 = x0*y0 */
internal_mul(x1y1, x1, y1) or_return; /* x1y1 = x1*y1 */
internal_add(t1, x1, x0) or_return; /* now calc x1+x0 and */
internal_add(x0, y1, y0) or_return; /* t2 = y1 + y0 */
internal_mul(t1, t1, x0) or_return; /* t1 = (x1 + x0) * (y1 + y0) */
/*
Add x0y0.
*/
internal_add(x0, x0y0, x1y1) or_return; /* t2 = x0y0 + x1y1 */
internal_sub(t1, t1, x0) or_return; /* t1 = (x1+x0)*(y1+y0) - (x1y1 + x0y0) */
/*
shift by B.
*/
internal_shl_digit(t1, B) or_return; /* t1 = (x0y0 + x1y1 - (x1-x0)*(y1-y0))<<B */
internal_shl_digit(x1y1, B * 2) or_return; /* x1y1 = x1y1 << 2*B */
internal_add(t1, x0y0, t1) or_return; /* t1 = x0y0 + t1 */
internal_add(dest, t1, x1y1) or_return; /* t1 = x0y0 + t1 + x1y1 */
return nil;
}
/*
Fast (comba) multiplier
@@ -1629,7 +1868,7 @@ _private_log_power_of_two :: proc(a: ^Int, base: DIGIT) -> (log: int, err: Error
Copies DIGITs from `src` to `dest`.
Assumes `src` and `dest` to not be `nil` and have been initialized.
*/
_private_copy_digits :: proc(dest, src: ^Int, digits: int) -> (err: Error) {
_private_copy_digits :: proc(dest, src: ^Int, digits: int, offset := int(0)) -> (err: Error) {
digits := digits;
/*
If dest == src, do nothing
@@ -1639,7 +1878,7 @@ _private_copy_digits :: proc(dest, src: ^Int, digits: int) -> (err: Error) {
}
digits = min(digits, len(src.digit), len(dest.digit));
mem.copy_non_overlapping(&dest.digit[0], &src.digit[0], size_of(DIGIT) * digits);
mem.copy_non_overlapping(&dest.digit[0], &src.digit[offset], size_of(DIGIT) * digits);
return nil;
}

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@@ -446,6 +446,7 @@ TESTS = {
test_mul: [
[ 1234, 5432],
[ 0xd3b4e926aaba3040e1c12b5ea553b5, 0x1a821e41257ed9281bee5bc7789ea7 ],
[ 1 << 21_105, 1 << 21_501 ],
],
test_sqr: [
[ 5432],
@@ -531,7 +532,7 @@ TESTS = {
if not args.fast_tests:
TESTS[test_factorial].append(
# This one on its own takes around 800ms, so we exclude it for FAST_TESTS
[ 100_000 ],
[ 10_000 ],
)
total_passes = 0