1 files changed, 150 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/l-bit32.lua b/tex/context/base/mkiv/l-bit32.lua
new file mode 100644
index 000000000..5f35b8fee
--- /dev/null
+++ b/tex/context/base/mkiv/l-bit32.lua
@@ -0,0 +1,150 @@
+if not modules then modules = { } end modules ['l-bit32'] = {
+    version = 1.001,
+    license = "the same as regular Lua",
+    source  = "bitwise.lua, v 1.24 2014/12/26 17:20:53 roberto",
+    comment = "drop-in for bit32, adapted a bit by Hans Hagen",
+
+}
+
+-- Lua 5.3 has bitwise operators built in but code meant for 5.2 can expect the
+-- bit32 library to be present. For the moment (and maybe forever) we will ship
+-- the bit32 library as part of LuaTeX bit just in case it is missing, here is a
+-- drop-in. The code is an adapted version of code by Roberto. The Luajit variant
+-- is a mixture of mapping and magic.
+
+if bit32 then
+
+    -- lua 5.2: we're okay
+
+elseif utf8 then
+
+    -- lua 5.3:  bitwise.lua, v 1.24 2014/12/26 17:20:53 roberto
+
+    bit32 = load ( [[
+local select = select -- instead of: arg = { ... }
+
+bit32 = {
+  bnot = function (a)
+    return ~a & 0xFFFFFFFF
+  end,
+  band = function (x, y, z, ...)
+    if not z then
+      return ((x or -1) & (y or -1)) & 0xFFFFFFFF
+    else
+      local res = x & y & z
+      for i=1,select("#",...) do
+        res = res & select(i,...)
+      end
+      return res & 0xFFFFFFFF
+    end
+  end,
+  bor = function (x, y, z, ...)
+    if not z then
+      return ((x or 0) | (y or 0)) & 0xFFFFFFFF
+    else
+      local res = x | y | z
+      for i=1,select("#",...) do
+        res = res | select(i,...)
+      end
+      return res & 0xFFFFFFFF
+    end
+  end,
+  bxor = function (x, y, z, ...)
+    if not z then
+      return ((x or 0) ~ (y or 0)) & 0xFFFFFFFF
+    else
+      local res = x ~ y ~ z
+      for i=1,select("#",...) do
+        res = res ~ select(i,...)
+      end
+      return res & 0xFFFFFFFF
+    end
+  end,
+  btest = function (x, y, z, ...)
+    if not z then
+      return (((x or -1) & (y or -1)) & 0xFFFFFFFF) ~= 0
+    else
+      local res = x & y & z
+      for i=1,select("#",...) do
+          res = res & select(i,...)
+      end
+      return (res & 0xFFFFFFFF) ~= 0
+    end
+  end,
+  lshift = function (a, b)
+    return ((a & 0xFFFFFFFF) << b) & 0xFFFFFFFF
+  end,
+  rshift = function (a, b)
+    return ((a & 0xFFFFFFFF) >> b) & 0xFFFFFFFF
+  end,
+  arshift = function (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,
+  lrotate = function (a ,b)
+    b = b & 31
+    a = a & 0xFFFFFFFF
+    a = (a << b) | (a >> (32 - b))
+    return a & 0xFFFFFFFF
+  end,
+  rrotate = function (a, b)
+    b = -b & 31
+    a = a & 0xFFFFFFFF
+    a = (a << b) | (a >> (32 - b))
+    return a & 0xFFFFFFFF
+  end,
+  extract = function (a, f, w)
+    return (a >> f) & ~(-1 << (w or 1))
+  end,
+  replace = function (a, v, f, w)
+    local mask = ~(-1 << (w or 1))
+    return ((a & ~(mask << f)) | ((v & mask) << f)) & 0xFFFFFFFF
+  end,
+}
+        ]] )
+
+elseif bit then
+
+    -- luajit (for now)
+
+    bit32 = load ( [[
+local band, bnot, rshift, lshift = bit.band, bit.bnot, bit.rshift, bit.lshift
+
+bit32 = {
+  arshift = bit.arshift,
+  band    = band,
+  bnot    = bnot,
+  bor     = bit.bor,
+  bxor    = bit.bxor,
+  btest   = function(...)
+    return band(...) ~= 0
+  end,
+  extract = function(a,f,w)
+    return band(rshift(a,f),2^(w or 1)-1)
+  end,
+  lrotate = bit.rol,
+  lshift  = lshift,
+  replace = function(a,v,f,w)
+    local mask = 2^(w or 1)-1
+    return band(a,bnot(lshift(mask,f)))+lshift(band(v,mask),f)
+  end,
+  rrotate = bit.ror,
+  rshift  = rshift,
+}
+        ]] )
+
+else
+
+    -- hope for the best or fail
+
+ -- bit32 = require("bit32")
+
+    xpcall(function() local _, t = require("bit32") if t then bit32 = t end return end,function() end)
+
+end
+
+return bit32 or false