98 lines
1.7 KiB
Lua
98 lines
1.7 KiB
Lua
|
bit32 = {}
|
||
|
|
|
||
|
|
local N = 32
|
||
|
|
local P = 2^N
|
||
|
|
|
||
|
|
bit32.bnot = function(x)
|
||
|
|
x = x%P
|
||
|
|
return P-1-x
|
||
|
|
end
|
||
|
|
|
||
|
|
bit32.band = function(x, y)
|
||
|
|
-- Common usecases, they deserve to be optimized
|
||
|
|
if y == 0xff then return x%0x100 end
|
||
|
|
if y == 0xffff then return x%0x10000 end
|
||
|
|
if y == 0xffffffff then return x%0x100000000 end
|
||
|
|
|
||
|
|
x, y = x%P, y%P
|
||
|
|
local r = 0
|
||
|
|
local p = 1
|
||
|
|
for i = 1, N do
|
||
|
|
a, b = x%2, y%2
|
||
|
|
x, y = math.floor(x/2), math.floor(y/2)
|
||
|
|
if a+b == 2 then
|
||
|
|
r = r + p
|
||
|
|
end
|
||
|
|
p = 2*p
|
||
|
|
end
|
||
|
|
return r
|
||
|
|
end
|
||
|
|
|
||
|
|
bit32.bor = function(x, y)
|
||
|
|
-- Common usecases, they deserve to be optimized
|
||
|
|
if y == 0xff then return x%0x100 end
|
||
|
|
if y == 0xffff then return x%0x10000 end
|
||
|
|
|
||
|
|
x, y = x%P, y%P
|
||
|
|
local r = 0
|
||
|
|
local p = 1
|
||
|
|
for i = 1, N do
|
||
|
|
a, b = x%2, y%2
|
||
|
|
x, y = math.floor(x/2), math.floor(y/2)
|
||
|
|
if a+b >= 1 then
|
||
|
|
r = r + p
|
||
|
|
end
|
||
|
|
p = 2*p
|
||
|
|
end
|
||
|
|
return r
|
||
|
|
end
|
||
|
|
|
||
|
|
bit32.bxor = function(x, y)
|
||
|
|
x, y = x%P, y%P
|
||
|
|
local r = 0
|
||
|
|
local p = 1
|
||
|
|
for i = 1, N do
|
||
|
|
a, b = x%2, y%2
|
||
|
|
x, y = math.floor(x/2), math.floor(y/2)
|
||
|
|
if a+b == 1 then
|
||
|
|
r = r + p
|
||
|
|
end
|
||
|
|
p = 2*p
|
||
|
|
end
|
||
|
|
return r
|
||
|
|
end
|
||
|
|
|
||
|
|
bit32.lshift = function(x, s_amount)
|
||
|
|
if math.abs(s_amount) >= N then return 0 end
|
||
|
|
x = x%P
|
||
|
|
if s_amount < 0 then
|
||
|
|
return math.floor(x*(2^s_amount))
|
||
|
|
else
|
||
|
|
return (x*(2^s_amount))%P
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
bit32.rshift = function(x, s_amount)
|
||
|
|
if math.abs(s_amount) >= N then return 0 end
|
||
|
|
x = x%P
|
||
|
|
if s_amount > 0 then
|
||
|
|
return math.floor(x*(2^-s_amount))
|
||
|
|
else
|
||
|
|
return (x*(2^-s_amount))%P
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
bit32.arshift = function(x, s_amount)
|
||
|
|
if math.abs(s_amount) >= N then return 0 end
|
||
|
|
x = x%P
|
||
|
|
if s_amount > 0 then
|
||
|
|
local add = 0
|
||
|
|
if x >= P/2 then
|
||
|
|
add = P - 2^(N-s_amount)
|
||
|
|
end
|
||
|
|
return math.floor(x*(2^-s_amount))+add
|
||
|
|
else
|
||
|
|
return (x*(2^-s_amount))%P
|
||
|
|
end
|
||
|
|
end
|