math.big: remove import math dependency (math.big only uses min/max/abs)

Author: spytheman

vlib/math/big/array_ops.v

@@ -1,7 +1,5 @@
 module big
 
-import math
-
 // Compares the magnitude of the two unsigned integers represented the given
 // digit arrays. Returns -1 if a < b, 0 if a == b and +1 if a > b. Here
 // a is operand_a and b is operand_b (for brevity).
@@ -42,8 +40,8 @@ fn add_digit_array(operand_a []u32, operand_b []u32, mut sum []u32) {
 	}
 
 	// First pass intersects with both operands
-	smaller_limit := math.min(operand_a.len, operand_b.len)
-	larger_limit := math.max(operand_a.len, operand_b.len)
+	smaller_limit := imin(operand_a.len, operand_b.len)
+	larger_limit := imax(operand_a.len, operand_b.len)
 	mut a, mut b := if operand_a.len >= operand_b.len {
 		operand_a, operand_b
 	} else {
@@ -311,7 +309,7 @@ fn bitwise_or_digit_array(operand_a []u32, operand_b []u32, mut storage []u32) {
 
 [direct_array_access]
 fn bitwise_and_digit_array(operand_a []u32, operand_b []u32, mut storage []u32) {
-	lower := math.min(operand_a.len, operand_b.len)
+	lower := imin(operand_a.len, operand_b.len)
 	for index in 0 .. lower {
 		storage[index] = operand_a[index] & operand_b[index]
 	}

vlib/math/big/integer.v

@@ -1,13 +1,10 @@
 module big
 
-import math
 import math.bits
 import strings
 import strconv
 
-const (
-	digit_array = '0123456789abcdefghijklmnopqrstuvwxyz'.bytes()
-)
+const digit_array = '0123456789abcdefghijklmnopqrstuvwxyz'.bytes()
 
 // big.Integer
 // -----------
@@ -55,7 +52,7 @@ pub fn integer_from_int(value int) Integer {
 		return zero_int
 	}
 	return Integer{
-		digits: [u32(math.abs(value))]
+		digits: [u32(iabs(value))]
 		signum: int_signum(value)
 	}
 }
@@ -327,7 +324,7 @@ pub fn (integer Integer) - (subtrahend Integer) Integer {
 fn (integer Integer) add(addend Integer) Integer {
 	a := integer.digits
 	b := addend.digits
-	mut storage := []u32{len: math.max(a.len, b.len) + 1}
+	mut storage := []u32{len: imax(a.len, b.len) + 1}
 	add_digit_array(a, b, mut storage)
 	return Integer{
 		signum: integer.signum
@@ -585,7 +582,7 @@ pub fn (mut a Integer) set_bit(i u32, value bool) {
 pub fn (a Integer) bitwise_or(b Integer) Integer {
 	check_sign(a)
 	check_sign(b)
-	mut result := []u32{len: math.max(a.digits.len, b.digits.len)}
+	mut result := []u32{len: imax(a.digits.len, b.digits.len)}
 	bitwise_or_digit_array(a.digits, b.digits, mut result)
 	return Integer{
 		digits: result
@@ -597,7 +594,7 @@ pub fn (a Integer) bitwise_or(b Integer) Integer {
 pub fn (a Integer) bitwise_and(b Integer) Integer {
 	check_sign(a)
 	check_sign(b)
-	mut result := []u32{len: math.max(a.digits.len, b.digits.len)}
+	mut result := []u32{len: imax(a.digits.len, b.digits.len)}
 	bitwise_and_digit_array(a.digits, b.digits, mut result)
 	return Integer{
 		digits: result
@@ -620,7 +617,7 @@ pub fn (a Integer) bitwise_not() Integer {
 pub fn (a Integer) bitwise_xor(b Integer) Integer {
 	check_sign(a)
 	check_sign(b)
-	mut result := []u32{len: math.max(a.digits.len, b.digits.len)}
+	mut result := []u32{len: imax(a.digits.len, b.digits.len)}
 	bitwise_xor_digit_array(a.digits, b.digits, mut result)
 	return Integer{
 		digits: result
@@ -941,7 +938,7 @@ fn gcd_binary(x Integer, y Integer) Integer {
 
 	mut az := a.msb()
 	bz := b.msb()
-	shift := math.min(az, bz)
+	shift := umin(az, bz)
 	b = b.rshift(bz)
 
 	for a.signum != 0 {

vlib/math/big/min_max.v

@@ -0,0 +1,26 @@
+module big
+
+[inline]
+fn imax(a int, b int) int {
+	return if a > b { a } else { b }
+}
+
+[inline]
+fn imin(a int, b int) int {
+	return if a < b { a } else { b }
+}
+
+[inline]
+fn umax(a u32, b u32) u32 {
+	return if a > b { a } else { b }
+}
+
+[inline]
+fn umin(a u32, b u32) u32 {
+	return if a < b { a } else { b }
+}
+
+[inline]
+fn iabs(v int) int {
+	return if v > 0 { v } else { -v }
+}

vlib/math/big/special_array_ops.v

@@ -1,6 +1,5 @@
 module big
 
-import math
 import math.bits
 import strings
 
@@ -113,7 +112,7 @@ fn karatsuba_multiply_digit_array(operand_a []u32, operand_b []u32, mut storage
 	}
 
 	// thanks to the base cases we can pass zero-length arrays to the mult func
-	half := math.max(operand_a.len, operand_b.len) / 2
+	half := imax(operand_a.len, operand_b.len) / 2
 	a_l := operand_a[0..half]
 	a_h := operand_a[half..]
 	mut b_l := []u32{}
@@ -132,8 +131,8 @@ fn karatsuba_multiply_digit_array(operand_a []u32, operand_b []u32, mut storage
 	mut p_3 := []u32{len: a_l.len + b_l.len + 1}
 	multiply_digit_array(a_l, b_l, mut p_3)
 
-	mut tmp_1 := []u32{len: math.max(a_h.len, a_l.len) + 1}
-	mut tmp_2 := []u32{len: math.max(b_h.len, b_l.len) + 1}
+	mut tmp_1 := []u32{len: imax(a_h.len, a_l.len) + 1}
+	mut tmp_2 := []u32{len: imax(b_h.len, b_l.len) + 1}
 	add_digit_array(a_h, a_l, mut tmp_1)
 	add_digit_array(b_h, b_l, mut tmp_2)
 
@@ -288,8 +287,8 @@ fn rshift_digits_in_place(mut a []u32, amount int) {
 fn add_in_place(mut a []u32, b []u32) {
 	len_a := a.len
 	len_b := b.len
-	max := math.max(len_a, len_b)
-	min := math.min(len_a, len_b)
+	max := imax(len_a, len_b)
+	min := imin(len_a, len_b)
 	mut carry := u64(0)
 	for index in 0 .. min {
 		partial := carry + a[index] + b[index]
@@ -316,8 +315,8 @@ fn add_in_place(mut a []u32, b []u32) {
 fn subtract_in_place(mut a []u32, b []u32) {
 	len_a := a.len
 	len_b := b.len
-	max := math.max(len_a, len_b)
-	min := math.min(len_a, len_b)
+	max := imax(len_a, len_b)
+	min := imin(len_a, len_b)
 	mut carry := u32(0)
 	mut new_carry := u32(0)
 	for index in 0 .. min {