big: More ZII refactoring.

This commit is contained in:
Jeroen van Rijn
2021-07-21 09:06:28 +02:00
parent 2e372b33a3
commit d9efa6c8b5
5 changed files with 87 additions and 43 deletions

View File

@@ -25,7 +25,11 @@ import "core:intrinsics"
*/
int_add :: proc(dest, a, b: ^Int) -> (err: Error) {
dest := dest; x := a; y := b;
assert_initialized(dest); assert_initialized(a); assert_initialized(b);
if dest == nil || a == nil || b == nil {
return .Nil_Pointer_Passed;
} else if !is_initialized(a) || !is_initialized(b) {
return .Int_Not_Initialized;
}
/*
Handle both negative or both positive.
@@ -56,8 +60,11 @@ int_add :: proc(dest, a, b: ^Int) -> (err: Error) {
*/
int_add_digit :: proc(dest, a: ^Int, digit: DIGIT) -> (err: Error) {
dest := dest; digit := digit;
assert_initialized(dest); assert_initialized(a);
if dest == nil || a == nil {
return .Nil_Pointer_Passed;
} else if !is_initialized(a) {
return .Int_Not_Initialized;
}
/*
Fast paths for destination and input Int being the same.
*/
@@ -81,8 +88,7 @@ int_add_digit :: proc(dest, a: ^Int, digit: DIGIT) -> (err: Error) {
/*
Grow destination as required.
*/
err = grow(dest, a.used + 1);
if err != .OK {
if err = grow(dest, a.used + 1); err != .OK {
return err;
}
@@ -170,7 +176,11 @@ int_add_digit :: proc(dest, a: ^Int, digit: DIGIT) -> (err: Error) {
*/
int_sub :: proc(dest, number, decrease: ^Int) -> (err: Error) {
dest := dest; x := number; y := decrease;
assert_initialized(number); assert_initialized(decrease); assert_initialized(dest);
if dest == nil || number == nil || decrease == nil {
return .Nil_Pointer_Passed;
} else if !(is_initialized(number) && is_initialized(decrease)) {
return .Int_Not_Initialized;
}
if x.sign != y.sign {
/*
@@ -210,7 +220,11 @@ int_sub :: proc(dest, number, decrease: ^Int) -> (err: Error) {
*/
int_sub_digit :: proc(dest, a: ^Int, digit: DIGIT) -> (err: Error) {
dest := dest; digit := digit;
assert_initialized(dest); assert_initialized(a);
if dest == nil || a == nil {
return .Nil_Pointer_Passed;
} else if !is_initialized(a) {
return .Int_Not_Initialized;
}
/*
Fast paths for destination and input Int being the same.
@@ -306,7 +320,11 @@ int_sub_digit :: proc(dest, a: ^Int, digit: DIGIT) -> (err: Error) {
*/
_int_add :: proc(dest, a, b: ^Int) -> (err: Error) {
dest := dest; x := a; y := b;
assert_initialized(a); assert_initialized(b); assert_initialized(dest);
if dest == nil || a == nil || b == nil {
return .Nil_Pointer_Passed;
} else if !is_initialized(a) || !is_initialized(b) {
return .Int_Not_Initialized;
}
old_used, min_used, max_used, i: int;
@@ -318,8 +336,7 @@ _int_add :: proc(dest, a, b: ^Int) -> (err: Error) {
max_used = y.used;
old_used = dest.used;
err = grow(dest, max(max_used + 1, _DEFAULT_DIGIT_COUNT));
if err != .OK {
if err = grow(dest, max(max_used + 1, _DEFAULT_DIGIT_COUNT)); err != .OK {
return err;
}
dest.used = max_used + 1;
@@ -387,15 +404,18 @@ _int_add :: proc(dest, a, b: ^Int) -> (err: Error) {
*/
_int_sub :: proc(dest, number, decrease: ^Int) -> (err: Error) {
dest := dest; x := number; y := decrease;
assert_initialized(number); assert_initialized(decrease); assert_initialized(dest);
if dest == nil || number == nil || decrease == nil {
return .Nil_Pointer_Passed;
} else if !is_initialized(number) || !is_initialized(decrease) {
return .Int_Not_Initialized;
}
old_used := dest.used;
min_used := y.used;
max_used := x.used;
i: int;
err = grow(dest, max(max_used, _DEFAULT_DIGIT_COUNT));
if err != .OK {
if err = grow(dest, max(max_used, _DEFAULT_DIGIT_COUNT)); err != .OK {
return err;
}
dest.used = max_used;

View File

@@ -44,9 +44,9 @@ _SQR_TOOM_CUTOFF,
print :: proc(name: string, a: ^Int, base := i8(16)) {
as, err := itoa(a, base);
defer delete(as);
if err == .OK {
fmt.printf("%v (base: %v, bits used: %v): %v\n", name, base, count_bits(a), as);
cb, _ := count_bits(a);
fmt.printf("%v (base: %v, bits used: %v): %v\n", name, base, cb, as);
} else {
fmt.printf("%v (error: %v): %v\n", name, err, a);
}

View File

@@ -328,7 +328,12 @@ minus_one :: proc { int_minus_one, };
power_of_two :: proc(a: ^Int, power: int) -> (err: Error) {
assert_initialized(a);
/*
Check that `a` is usable.
*/
if a == nil {
return .Nil_Pointer_Passed;
}
if power < 0 || power > _MAX_BIT_COUNT {
return .Invalid_Input;
@@ -356,13 +361,17 @@ power_of_two :: proc(a: ^Int, power: int) -> (err: Error) {
/*
Count bits in an `Int`.
*/
count_bits :: proc(a: ^Int) -> (count: int) {
assert_initialized(a);
count_bits :: proc(a: ^Int) -> (count: int, err: Error) {
if a == nil {
return 0, .Nil_Pointer_Passed;
} else if !is_initialized(a) {
return 0, .Int_Not_Initialized;
}
/*
Fast path for zero.
*/
if is_zero(a) {
return 0;
return 0, .OK;
}
/*
Get the number of DIGITs and use it.
@@ -384,7 +393,12 @@ assert_initialized :: proc(a: ^Int, loc := #caller_location) {
}
_zero_unused :: proc(a: ^Int) {
assert_initialized(a);
if a == nil {
return;
} else if !is_initialized(a) {
return;
}
if a.used < len(a.digit) {
mem.zero_slice(a.digit[a.used:]);
}
@@ -397,15 +411,18 @@ _grow_if_uninitialized :: proc(dest: ^Int, minimize := false) -> (err: Error) {
return .OK;
}
clamp :: proc(a: ^Int) {
assert_initialized(a);
/*
Trim unused digits
This is used to ensure that leading zero digits are
trimmed and the leading "used" digit will be non-zero.
Typically very fast. Also fixes the sign if there
are no more leading digits.
*/
/*
Trim unused digits.
This is used to ensure that leading zero digits are trimmed and the leading "used" digit will be non-zero.
Typically very fast. Also fixes the sign if there are no more leading digits.
*/
clamp :: proc(a: ^Int) -> (err: Error) {
if a == nil {
return .Nil_Pointer_Passed;
} else if !is_initialized(a) {
return .Int_Not_Initialized;
}
for a.used > 0 && a.digit[a.used - 1] == 0 {
a.used -= 1;
@@ -414,5 +431,6 @@ clamp :: proc(a: ^Int) {
if is_zero(a) {
a.sign = .Zero_or_Positive;
}
}
return .OK;
}

View File

@@ -10,7 +10,11 @@ package big
*/
log_n_int :: proc(a: ^Int, base: DIGIT) -> (log: int, err: Error) {
assert_initialized(a);
if a == nil {
return 0, .Nil_Pointer_Passed;
} else if !is_initialized(a) {
return 0, .Int_Not_Initialized;
}
if is_neg(a) || is_zero(a) || base < 2 || DIGIT(base) > _DIGIT_MAX {
return -1, .Invalid_Input;
}
@@ -19,14 +23,14 @@ log_n_int :: proc(a: ^Int, base: DIGIT) -> (log: int, err: Error) {
Fast path for bases that are a power of two.
*/
if is_power_of_two(int(base)) {
return _log_power_of_two(a, base), .OK;
return _log_power_of_two(a, base);
}
/*
Fast path for `Int`s that fit within a single `DIGIT`.
*/
if a.used == 1 {
return log_n_digit(a.digit[0], DIGIT(base)), .OK;
return log_n_digit(a.digit[0], DIGIT(base));
}
// if (MP_HAS(S_MP_LOG)) {
@@ -42,14 +46,15 @@ log_n :: proc{log_n_int, log_n_digit};
Returns the log2 of an `Int`, provided `base` is a power of two.
Don't call it if it isn't.
*/
_log_power_of_two :: proc(a: ^Int, base: DIGIT) -> (log: int) {
_log_power_of_two :: proc(a: ^Int, base: DIGIT) -> (log: int, err: Error) {
base := base;
y: int;
for y = 0; base & 1 == 0; {
y += 1;
base >>= 1;
}
return (count_bits(a) - 1) / y;
log, err = count_bits(a);
return (log - 1) / y, err;
}
/*
@@ -69,20 +74,20 @@ small_pow :: proc(base: _WORD, exponent: _WORD) -> (result: _WORD) {
return result;
}
log_n_digit :: proc(a: DIGIT, base: DIGIT) -> (log: int) {
log_n_digit :: proc(a: DIGIT, base: DIGIT) -> (log: int, err: Error) {
/*
If the number is smaller than the base, it fits within a fraction.
Therefore, we return 0.
*/
if a < base {
return 0;
return 0, .OK;
}
/*
If a number equals the base, the log is 1.
*/
if a == base {
return 1;
return 1, .OK;
}
N := _WORD(a);
@@ -111,13 +116,13 @@ log_n_digit :: proc(a: DIGIT, base: DIGIT) -> (log: int) {
bracket_low = bracket_mid;
}
if N == bracket_mid {
return mid;
return mid, .OK;
}
}
if bracket_high == N {
return high;
return high, .OK;
} else {
return low;
return low, .OK;
}
}

View File

@@ -198,9 +198,10 @@ itoa_raw :: proc(a: ^Int, radix: i8, buffer: []u8, size := int(-1), zero_termina
buffer[available] = 0;
}
shift, count: int;
// mask := _WORD(radix - 1);
shift := int(log_n(DIGIT(radix), 2));
count := int(count_bits(a));
shift, err = log_n(DIGIT(radix), 2);
count, err = count_bits(a);
// digit: _WORD;
for offset := 0; offset < count; offset += 4 {