Bit arithmetic acceleration technique
1. If you multiply the value of the previous 2, you can use the left shift operation to accelerate the 300%
x = x * 2;
x = x * 64;
Switch
x = x << 1; 2 = 21
x = x << 6; 64 = 26
2. If the number of multiples in addition to the previous 2, you can use the right-shift operation to accelerate 350%
x = X/2;
x = X/64;
Switch
x = x >> 1;//2 = 21
x = x >> 6;//64 = 26
3. numeric to integer acceleration 10%
x = Int (1.232)
Switch
x = 1.232 >> 0;
4. swap two values (swap) and use XOR to accelerate 20%
var t:int = A;
A = b;
b = t;
Switch
A = A^b;
b = a^b;
A = A^b;
5. sign conversion, can join 300%
i =-I.;
Switch
i = ~i + 1; Not notation
Or
i = (i ^-1) + 1; XOR notation
6. Take the remainder, if the divisor is a multiple of 2, can use the and operation to accelerate the 600%
x = 131% 4;
Switch
x = 131 & (4-1);
7. Use the and operation to check if the integer is a multiple of 2 to accelerate the 600%
IsEven = (i% 2) = = 0;
Switch
IsEven = (I & 1) = = 0;
8. Accelerate the writing of Math.Abs 600% 1, 2 is faster than the wording of 1 20%
Notation 1
i = x < 0? -x:x;
Notation 2
i = (x ^ (x >>))-(x >> 31);
Notation 3
i=x^ (~ (x>>31) +1) + (x>>31);
9. Compare if you have the same symbol after multiplying the two values, accelerating 35%
Eqsign = A * b > 0;
equals
Eqsign = a ^ b > 0;
Other bit arithmetic techniques:
1. RGB Color Separation
var 24bitcolor:uint = 0xff00cc;
var r:uint = 24bitColor >> 16;
var g:uint = 24bitColor >> 8 & 0xFF;
var b:uint = 24bitColor & 0xFF;
2. RGB Color Merge
var r:uint = 0xFF;
var g:uint = 0x00;
var b:uint = 0xcc;
var 24bitcolor:uint = r << 16 | G << 8 | b
Bit arithmetic in C language