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authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>2018-12-17 14:46:37 -0200
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>2018-12-17 14:46:37 -0200
commit063d4e4543088e7a21965bda8ee5a0f952a9029e (patch)
tree6c3f2f8e98c26f071a94a32f9f2754396a66a9de /testes/bitwise.lua
parente354c6355e7f48e087678ec49e340ca0696725b1 (diff)
downloadlua-github-5.3.5.tar.gz
Lua 5.3.5 ported to gitv5.3.5v5-3-5
This is the first commit for the branch Lua 5.3. All source files were copied from the official distribution of 5.3.5 in the Lua site. The test files are the same of 5.3.4. The manual came from the previous RCS repository, revision 1.167.1.2.
Diffstat (limited to 'testes/bitwise.lua')
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diff --git a/testes/bitwise.lua b/testes/bitwise.lua
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+-- $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'
+