- Add bitop

assets/bitop.lua

@@ -0,0 +1,366 @@
+local M = {_TYPE='module', _NAME='bitop.funcs', _VERSION='1.0-0'}
+
+local floor = math.floor
+
+local MOD = 2 ^ 32
+local MODM = MOD - 1
+
+local function memoize(f)
+
+    local mt = {}
+    local t = setmetatable({}, mt)
+
+    function mt:__index(k)
+        local v = f(k)
+        t[k] = v
+        return v
+    end
+
+    return t
+end
+
+local function make_bitop_uncached(t, m)
+    local function bitop(a, b)
+        local res, p = 0, 1
+        while a ~= 0 and b ~= 0 do
+            local am, bm = a % m, b % m
+            res = res + t[am][bm] * p
+            a = (a - am) / m
+            b = (b - bm) / m
+            p = p * m
+        end
+        res = res + (a + b) * p
+        return res
+    end
+    return bitop
+end
+
+local function make_bitop(t)
+    local op1 = make_bitop_uncached(t, 2 ^ 1)
+    local op2 = memoize(function(a)
+        return memoize(function(b)
+            return op1(a, b)
+        end)
+    end)
+    return make_bitop_uncached(op2, 2 ^ (t.n or 1))
+end
+
+-- ok? probably not if running on a 32-bit int Lua number type platform
+function M.tobit(x)
+    return x % 2 ^ 32
+end
+
+M.bxor = make_bitop{[0]={[0]=0, [1]=1}, [1]={[0]=1, [1]=0}, n=4}
+local bxor = M.bxor
+
+function M.bnot(a)
+    return MODM - a
+end
+local bnot = M.bnot
+
+function M.band(a, b)
+    return ((a + b) - bxor(a, b)) / 2
+end
+local band = M.band
+
+function M.bor(a, b)
+    return MODM - band(MODM - a, MODM - b)
+end
+local bor = M.bor
+
+local lshift, rshift -- forward declare
+
+function M.rshift(a, disp) -- Lua5.2 insipred
+    if disp < 0 then
+        return lshift(a, -disp)
+    end
+    return floor(a % 2 ^ 32 / 2 ^ disp)
+end
+rshift = M.rshift
+
+function M.lshift(a, disp) -- Lua5.2 inspired
+    if disp < 0 then
+        return rshift(a, -disp)
+    end
+    return (a * 2 ^ disp) % 2 ^ 32
+end
+lshift = M.lshift
+
+function M.tohex(x, n) -- BitOp style
+    n = n or 8
+    local up
+    if n <= 0 then
+        if n == 0 then
+            return ''
+        end
+        up = true
+        n = -n
+    end
+    x = band(x, 16 ^ n - 1)
+    return ('%0' .. n .. (up and 'X' or 'x')):format(x)
+end
+local tohex = M.tohex
+
+function M.extract(n, field, width) -- Lua5.2 inspired
+    width = width or 1
+    return band(rshift(n, field), 2 ^ width - 1)
+end
+local extract = M.extract
+
+function M.replace(n, v, field, width) -- Lua5.2 inspired
+    width = width or 1
+    local mask1 = 2 ^ width - 1
+    v = band(v, mask1) -- required by spec?
+    local mask = bnot(lshift(mask1, field))
+    return band(n, mask) + lshift(v, field)
+end
+local replace = M.replace
+
+function M.bswap(x) -- BitOp style
+    local a = band(x, 0xff);
+    x = rshift(x, 8)
+    local b = band(x, 0xff);
+    x = rshift(x, 8)
+    local c = band(x, 0xff);
+    x = rshift(x, 8)
+    local d = band(x, 0xff)
+    return lshift(lshift(lshift(a, 8) + b, 8) + c, 8) + d
+end
+local bswap = M.bswap
+
+function M.rrotate(x, disp) -- Lua5.2 inspired
+    disp = disp % 32
+    local low = band(x, 2 ^ disp - 1)
+    return rshift(x, disp) + lshift(low, 32 - disp)
+end
+local rrotate = M.rrotate
+
+function M.lrotate(x, disp) -- Lua5.2 inspired
+    return rrotate(x, -disp)
+end
+local lrotate = M.lrotate
+
+M.rol = M.lrotate -- LuaOp inspired
+M.ror = M.rrotate -- LuaOp insipred
+
+function M.arshift(x, disp) -- Lua5.2 inspired
+    local z = rshift(x, disp)
+    if x >= 0x80000000 then
+        z = z + lshift(2 ^ disp - 1, 32 - disp)
+    end
+    return z
+end
+local arshift = M.arshift
+
+function M.btest(x, y) -- Lua5.2 inspired
+    return band(x, y) ~= 0
+end
+
+--
+-- Start Lua 5.2 "bit32" compat section.
+--
+
+M.bit32 = {} -- Lua 5.2 'bit32' compatibility
+
+local function bit32_bnot(x)
+    return (-1 - x) % MOD
+end
+M.bit32.bnot = bit32_bnot
+
+local function bit32_bxor(a, b, c, ...)
+    local z
+    if b then
+        a = a % MOD
+        b = b % MOD
+        z = bxor(a, b)
+        if c then
+            z = bit32_bxor(z, c, ...)
+        end
+        return z
+    elseif a then
+        return a % MOD
+    else
+        return 0
+    end
+end
+M.bit32.bxor = bit32_bxor
+
+local function bit32_band(a, b, c, ...)
+    local z
+    if b then
+        a = a % MOD
+        b = b % MOD
+        z = ((a + b) - bxor(a, b)) / 2
+        if c then
+            z = bit32_band(z, c, ...)
+        end
+        return z
+    elseif a then
+        return a % MOD
+    else
+        return MODM
+    end
+end
+M.bit32.band = bit32_band
+
+local function bit32_bor(a, b, c, ...)
+    local z
+    if b then
+        a = a % MOD
+        b = b % MOD
+        z = MODM - band(MODM - a, MODM - b)
+        if c then
+            z = bit32_bor(z, c, ...)
+        end
+        return z
+    elseif a then
+        return a % MOD
+    else
+        return 0
+    end
+end
+M.bit32.bor = bit32_bor
+
+function M.bit32.btest(...)
+    return bit32_band(...) ~= 0
+end
+
+function M.bit32.lrotate(x, disp)
+    return lrotate(x % MOD, disp)
+end
+
+function M.bit32.rrotate(x, disp)
+    return rrotate(x % MOD, disp)
+end
+
+function M.bit32.lshift(x, disp)
+    if disp > 31 or disp < -31 then
+        return 0
+    end
+    return lshift(x % MOD, disp)
+end
+
+function M.bit32.rshift(x, disp)
+    if disp > 31 or disp < -31 then
+        return 0
+    end
+    return rshift(x % MOD, disp)
+end
+
+function M.bit32.arshift(x, disp)
+    x = x % MOD
+    if disp >= 0 then
+        if disp > 31 then
+            return (x >= 0x80000000) and MODM or 0
+        else
+            local z = rshift(x, disp)
+            if x >= 0x80000000 then
+                z = z + lshift(2 ^ disp - 1, 32 - disp)
+            end
+            return z
+        end
+    else
+        return lshift(x, -disp)
+    end
+end
+
+function M.bit32.extract(x, field, ...)
+    local width = ... or 1
+    if field < 0 or field > 31 or width < 0 or field + width > 32 then
+        error'out of range'
+    end
+    x = x % MOD
+    return extract(x, field, ...)
+end
+
+function M.bit32.replace(x, v, field, ...)
+    local width = ... or 1
+    if field < 0 or field > 31 or width < 0 or field + width > 32 then
+        error'out of range'
+    end
+    x = x % MOD
+    v = v % MOD
+    return replace(x, v, field, ...)
+end
+
+--
+-- Start LuaBitOp "bit" compat section.
+--
+
+M.bit = {} -- LuaBitOp "bit" compatibility
+
+function M.bit.tobit(x)
+    x = x % MOD
+    if x >= 0x80000000 then
+        x = x - MOD
+    end
+    return x
+end
+local bit_tobit = M.bit.tobit
+
+function M.bit.tohex(x, ...)
+    return tohex(x % MOD, ...)
+end
+
+function M.bit.bnot(x)
+    return bit_tobit(bnot(x % MOD))
+end
+
+local function bit_bor(a, b, c, ...)
+    if c then
+        return bit_bor(bit_bor(a, b), c, ...)
+    elseif b then
+        return bit_tobit(bor(a % MOD, b % MOD))
+    else
+        return bit_tobit(a)
+    end
+end
+M.bit.bor = bit_bor
+
+local function bit_band(a, b, c, ...)
+    if c then
+        return bit_band(bit_band(a, b), c, ...)
+    elseif b then
+        return bit_tobit(band(a % MOD, b % MOD))
+    else
+        return bit_tobit(a)
+    end
+end
+M.bit.band = bit_band
+
+local function bit_bxor(a, b, c, ...)
+    if c then
+        return bit_bxor(bit_bxor(a, b), c, ...)
+    elseif b then
+        return bit_tobit(bxor(a % MOD, b % MOD))
+    else
+        return bit_tobit(a)
+    end
+end
+M.bit.bxor = bit_bxor
+
+function M.bit.lshift(x, n)
+    return bit_tobit(lshift(x % MOD, n % 32))
+end
+
+function M.bit.rshift(x, n)
+    return bit_tobit(rshift(x % MOD, n % 32))
+end
+
+function M.bit.arshift(x, n)
+    return bit_tobit(arshift(x % MOD, n % 32))
+end
+
+function M.bit.rol(x, n)
+    return bit_tobit(lrotate(x % MOD, n % 32))
+end
+
+function M.bit.ror(x, n)
+    return bit_tobit(rrotate(x % MOD, n % 32))
+end
+
+function M.bit.bswap(x)
+    return bit_tobit(bswap(x % MOD))
+end
+
+return M

main.lua

@@ -40,6 +40,13 @@ love.setDeprecationOutput(false)
 love.keyboard.setTextInput(false)
 VERSION=require'version'
 
+-- Bit module
+local success
+success,bit=pcall(require,"bit")
+if not success then
+    bit=require"assets.bitop".bit
+end
+
 --------------------------------------------------------------
 -- Create directories