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Diffstat (limited to 'testes/bitwise.lua')
-rwxr-xr-x | testes/bitwise.lua | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/testes/bitwise.lua b/testes/bitwise.lua new file mode 100755 index 00000000..786679f4 --- /dev/null +++ b/testes/bitwise.lua @@ -0,0 +1,328 @@ +-- $Id: bitwise.lua,v 1.26 2016/11/07 13:11:28 roberto Exp $ +-- See Copyright Notice in file all.lua + +print("testing bitwise operations") + +local numbits = string.packsize('j') * 8 + +assert(~0 == -1) + +assert((1 << (numbits - 1)) == math.mininteger) + +-- basic tests for bitwise operators; +-- use variables to avoid constant folding +local a, b, c, d +a = 0xFFFFFFFFFFFFFFFF +assert(a == -1 and a & -1 == a and a & 35 == 35) +a = 0xF0F0F0F0F0F0F0F0 +assert(a | -1 == -1) +assert(a ~ a == 0 and a ~ 0 == a and a ~ ~a == -1) +assert(a >> 4 == ~a) +a = 0xF0; b = 0xCC; c = 0xAA; d = 0xFD +assert(a | b ~ c & d == 0xF4) + +a = 0xF0.0; b = 0xCC.0; c = "0xAA.0"; d = "0xFD.0" +assert(a | b ~ c & d == 0xF4) + +a = 0xF0000000; b = 0xCC000000; +c = 0xAA000000; d = 0xFD000000 +assert(a | b ~ c & d == 0xF4000000) +assert(~~a == a and ~a == -1 ~ a and -d == ~d + 1) + +a = a << 32 +b = b << 32 +c = c << 32 +d = d << 32 +assert(a | b ~ c & d == 0xF4000000 << 32) +assert(~~a == a and ~a == -1 ~ a and -d == ~d + 1) + +assert(-1 >> 1 == (1 << (numbits - 1)) - 1 and 1 << 31 == 0x80000000) +assert(-1 >> (numbits - 1) == 1) +assert(-1 >> numbits == 0 and + -1 >> -numbits == 0 and + -1 << numbits == 0 and + -1 << -numbits == 0) + +assert((2^30 - 1) << 2^30 == 0) +assert((2^30 - 1) >> 2^30 == 0) + +assert(1 >> -3 == 1 << 3 and 1000 >> 5 == 1000 << -5) + + +-- coercion from strings to integers +assert("0xffffffffffffffff" | 0 == -1) +assert("0xfffffffffffffffe" & "-1" == -2) +assert(" \t-0xfffffffffffffffe\n\t" & "-1" == 2) +assert(" \n -45 \t " >> " -2 " == -45 * 4) + +-- out of range number +assert(not pcall(function () return "0xffffffffffffffff.0" | 0 end)) + +-- embedded zeros +assert(not pcall(function () return "0xffffffffffffffff\0" | 0 end)) + +print'+' + + +package.preload.bit32 = function () --{ + +-- no built-in 'bit32' library: implement it using bitwise operators + +local bit = {} + +function bit.bnot (a) + return ~a & 0xFFFFFFFF +end + + +-- +-- in all vararg functions, avoid creating 'arg' table when there are +-- only 2 (or less) parameters, as 2 parameters is the common case +-- + +function bit.band (x, y, z, ...) + if not z then + return ((x or -1) & (y or -1)) & 0xFFFFFFFF + else + local arg = {...} + local res = x & y & z + for i = 1, #arg do res = res & arg[i] end + return res & 0xFFFFFFFF + end +end + +function bit.bor (x, y, z, ...) + if not z then + return ((x or 0) | (y or 0)) & 0xFFFFFFFF + else + local arg = {...} + local res = x | y | z + for i = 1, #arg do res = res | arg[i] end + return res & 0xFFFFFFFF + end +end + +function bit.bxor (x, y, z, ...) + if not z then + return ((x or 0) ~ (y or 0)) & 0xFFFFFFFF + else + local arg = {...} + local res = x ~ y ~ z + for i = 1, #arg do res = res ~ arg[i] end + return res & 0xFFFFFFFF + end +end + +function bit.btest (...) + return bit.band(...) ~= 0 +end + +function bit.lshift (a, b) + return ((a & 0xFFFFFFFF) << b) & 0xFFFFFFFF +end + +function bit.rshift (a, b) + return ((a & 0xFFFFFFFF) >> b) & 0xFFFFFFFF +end + +function bit.arshift (a, b) + a = a & 0xFFFFFFFF + if b <= 0 or (a & 0x80000000) == 0 then + return (a >> b) & 0xFFFFFFFF + else + return ((a >> b) | ~(0xFFFFFFFF >> b)) & 0xFFFFFFFF + end +end + +function bit.lrotate (a ,b) + b = b & 31 + a = a & 0xFFFFFFFF + a = (a << b) | (a >> (32 - b)) + return a & 0xFFFFFFFF +end + +function bit.rrotate (a, b) + return bit.lrotate(a, -b) +end + +local function checkfield (f, w) + w = w or 1 + assert(f >= 0, "field cannot be negative") + assert(w > 0, "width must be positive") + assert(f + w <= 32, "trying to access non-existent bits") + return f, ~(-1 << w) +end + +function bit.extract (a, f, w) + local f, mask = checkfield(f, w) + return (a >> f) & mask +end + +function bit.replace (a, v, f, w) + local f, mask = checkfield(f, w) + v = v & mask + a = (a & ~(mask << f)) | (v << f) + return a & 0xFFFFFFFF +end + +return bit + +end --} + + +print("testing bitwise library") + +local bit32 = require'bit32' + +assert(bit32.band() == bit32.bnot(0)) +assert(bit32.btest() == true) +assert(bit32.bor() == 0) +assert(bit32.bxor() == 0) + +assert(bit32.band() == bit32.band(0xffffffff)) +assert(bit32.band(1,2) == 0) + + +-- out-of-range numbers +assert(bit32.band(-1) == 0xffffffff) +assert(bit32.band((1 << 33) - 1) == 0xffffffff) +assert(bit32.band(-(1 << 33) - 1) == 0xffffffff) +assert(bit32.band((1 << 33) + 1) == 1) +assert(bit32.band(-(1 << 33) + 1) == 1) +assert(bit32.band(-(1 << 40)) == 0) +assert(bit32.band(1 << 40) == 0) +assert(bit32.band(-(1 << 40) - 2) == 0xfffffffe) +assert(bit32.band((1 << 40) - 4) == 0xfffffffc) + +assert(bit32.lrotate(0, -1) == 0) +assert(bit32.lrotate(0, 7) == 0) +assert(bit32.lrotate(0x12345678, 0) == 0x12345678) +assert(bit32.lrotate(0x12345678, 32) == 0x12345678) +assert(bit32.lrotate(0x12345678, 4) == 0x23456781) +assert(bit32.rrotate(0x12345678, -4) == 0x23456781) +assert(bit32.lrotate(0x12345678, -8) == 0x78123456) +assert(bit32.rrotate(0x12345678, 8) == 0x78123456) +assert(bit32.lrotate(0xaaaaaaaa, 2) == 0xaaaaaaaa) +assert(bit32.lrotate(0xaaaaaaaa, -2) == 0xaaaaaaaa) +for i = -50, 50 do + assert(bit32.lrotate(0x89abcdef, i) == bit32.lrotate(0x89abcdef, i%32)) +end + +assert(bit32.lshift(0x12345678, 4) == 0x23456780) +assert(bit32.lshift(0x12345678, 8) == 0x34567800) +assert(bit32.lshift(0x12345678, -4) == 0x01234567) +assert(bit32.lshift(0x12345678, -8) == 0x00123456) +assert(bit32.lshift(0x12345678, 32) == 0) +assert(bit32.lshift(0x12345678, -32) == 0) +assert(bit32.rshift(0x12345678, 4) == 0x01234567) +assert(bit32.rshift(0x12345678, 8) == 0x00123456) +assert(bit32.rshift(0x12345678, 32) == 0) +assert(bit32.rshift(0x12345678, -32) == 0) +assert(bit32.arshift(0x12345678, 0) == 0x12345678) +assert(bit32.arshift(0x12345678, 1) == 0x12345678 // 2) +assert(bit32.arshift(0x12345678, -1) == 0x12345678 * 2) +assert(bit32.arshift(-1, 1) == 0xffffffff) +assert(bit32.arshift(-1, 24) == 0xffffffff) +assert(bit32.arshift(-1, 32) == 0xffffffff) +assert(bit32.arshift(-1, -1) == bit32.band(-1 * 2, 0xffffffff)) + +assert(0x12345678 << 4 == 0x123456780) +assert(0x12345678 << 8 == 0x1234567800) +assert(0x12345678 << -4 == 0x01234567) +assert(0x12345678 << -8 == 0x00123456) +assert(0x12345678 << 32 == 0x1234567800000000) +assert(0x12345678 << -32 == 0) +assert(0x12345678 >> 4 == 0x01234567) +assert(0x12345678 >> 8 == 0x00123456) +assert(0x12345678 >> 32 == 0) +assert(0x12345678 >> -32 == 0x1234567800000000) + +print("+") +-- some special cases +local c = {0, 1, 2, 3, 10, 0x80000000, 0xaaaaaaaa, 0x55555555, + 0xffffffff, 0x7fffffff} + +for _, b in pairs(c) do + assert(bit32.band(b) == b) + assert(bit32.band(b, b) == b) + assert(bit32.band(b, b, b, b) == b) + assert(bit32.btest(b, b) == (b ~= 0)) + assert(bit32.band(b, b, b) == b) + assert(bit32.band(b, b, b, ~b) == 0) + assert(bit32.btest(b, b, b) == (b ~= 0)) + assert(bit32.band(b, bit32.bnot(b)) == 0) + assert(bit32.bor(b, bit32.bnot(b)) == bit32.bnot(0)) + assert(bit32.bor(b) == b) + assert(bit32.bor(b, b) == b) + assert(bit32.bor(b, b, b) == b) + assert(bit32.bor(b, b, 0, ~b) == 0xffffffff) + assert(bit32.bxor(b) == b) + assert(bit32.bxor(b, b) == 0) + assert(bit32.bxor(b, b, b) == b) + assert(bit32.bxor(b, b, b, b) == 0) + assert(bit32.bxor(b, 0) == b) + assert(bit32.bnot(b) ~= b) + assert(bit32.bnot(bit32.bnot(b)) == b) + assert(bit32.bnot(b) == (1 << 32) - 1 - b) + assert(bit32.lrotate(b, 32) == b) + assert(bit32.rrotate(b, 32) == b) + assert(bit32.lshift(bit32.lshift(b, -4), 4) == bit32.band(b, bit32.bnot(0xf))) + assert(bit32.rshift(bit32.rshift(b, 4), -4) == bit32.band(b, bit32.bnot(0xf))) +end + +-- for this test, use at most 24 bits (mantissa of a single float) +c = {0, 1, 2, 3, 10, 0x800000, 0xaaaaaa, 0x555555, 0xffffff, 0x7fffff} +for _, b in pairs(c) do + for i = -40, 40 do + local x = bit32.lshift(b, i) + local y = math.floor(math.fmod(b * 2.0^i, 2.0^32)) + assert(math.fmod(x - y, 2.0^32) == 0) + end +end + +assert(not pcall(bit32.band, {})) +assert(not pcall(bit32.bnot, "a")) +assert(not pcall(bit32.lshift, 45)) +assert(not pcall(bit32.lshift, 45, print)) +assert(not pcall(bit32.rshift, 45, print)) + +print("+") + + +-- testing extract/replace + +assert(bit32.extract(0x12345678, 0, 4) == 8) +assert(bit32.extract(0x12345678, 4, 4) == 7) +assert(bit32.extract(0xa0001111, 28, 4) == 0xa) +assert(bit32.extract(0xa0001111, 31, 1) == 1) +assert(bit32.extract(0x50000111, 31, 1) == 0) +assert(bit32.extract(0xf2345679, 0, 32) == 0xf2345679) + +assert(not pcall(bit32.extract, 0, -1)) +assert(not pcall(bit32.extract, 0, 32)) +assert(not pcall(bit32.extract, 0, 0, 33)) +assert(not pcall(bit32.extract, 0, 31, 2)) + +assert(bit32.replace(0x12345678, 5, 28, 4) == 0x52345678) +assert(bit32.replace(0x12345678, 0x87654321, 0, 32) == 0x87654321) +assert(bit32.replace(0, 1, 2) == 2^2) +assert(bit32.replace(0, -1, 4) == 2^4) +assert(bit32.replace(-1, 0, 31) == (1 << 31) - 1) +assert(bit32.replace(-1, 0, 1, 2) == (1 << 32) - 7) + + +-- testing conversion of floats + +assert(bit32.bor(3.0) == 3) +assert(bit32.bor(-4.0) == 0xfffffffc) + +-- large floats and large-enough integers? +if 2.0^50 < 2.0^50 + 1.0 and 2.0^50 < (-1 >> 1) then + assert(bit32.bor(2.0^32 - 5.0) == 0xfffffffb) + assert(bit32.bor(-2.0^32 - 6.0) == 0xfffffffa) + assert(bit32.bor(2.0^48 - 5.0) == 0xfffffffb) + assert(bit32.bor(-2.0^48 - 6.0) == 0xfffffffa) +end + +print'OK' + |