samples: add Terra samples

source: https://github.com/zdevito/terra/tree/master/tests

samples/Terra/blocking.t

@@ -0,0 +1,57 @@
+function symmat(name,I,...)
+	if not I then return symbol(name) end
+	local r = {}
+	for i = 1,I do
+		r[i] = symmat(name..tostring(i),...)
+	end
+	return r
+end
+
+terra min(a : int, b : int)
+	return terralib.select(a < b, a, b)
+end
+
+function blockedloop(bounds,sizes,bodyfn)
+	local indexes = symmat("i",#sizes,#bounds)
+	--local makeloop --bug local function doesn't add to set of live variables...
+	local function makeloop(s,b)
+			if s > #sizes then
+				return bodyfn(unpack(indexes[#sizes]))
+			elseif b > #bounds then
+				return makeloop(s + 1, 1)
+			else
+				local topbound = bounds[b]
+				local blocksize = sizes[s]
+				local begin,bound
+				if s == 1 then
+					begin,bound = 0, topbound
+				else
+					begin,bound = indexes[s-1][b], sizes[s-1]
+				end
+				local step = sizes[s]
+				return quote
+					for [indexes[s][b]] = begin,min(begin+bound,topbound),step do
+						[ makeloop(s,b+1) ]
+					end
+				end
+			end
+	end
+	return makeloop(1,1)
+end
+
+IO = terralib.includec("stdio.h")
+
+terra main()
+	
+	var M,N = 30,40;
+
+	[blockedloop({M,N}, {10,1}, function(m,n)
+		return quote 
+			IO.printf("%d %d\n",m,n)
+		end
+	end)]
+	
+end
+
+main:printpretty()
+main()