samples: add Terra samples

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

samples/Terra/blocking2.t

@@ -0,0 +1,81 @@
+terra min(a : int, b : int)
+	return terralib.select(a < b, a, b)
+end
+function blockedloop(N,blocksizes,bodyfn)
+	local function generatelevel(n,ii,jj,bb)
+		if n > #blocksizes then
+			return bodyfn(ii,jj)
+		end
+		local blocksize = blocksizes[n]
+		return quote
+			for i = ii,min(ii+bb,N),blocksize do
+				for j = jj,min(jj+bb,N),blocksize do
+					[ generatelevel(n+1,i,j,blocksize) ]
+				end
+			end
+		end
+	end
+	return generatelevel(1,0,0,N)
+end
+
+IO = terralib.includec("stdio.h")
+stdlib = terralib.includec("stdlib.h")
+
+terra main()
+	
+	var a : int[8][8]
+	var c = 0
+	var N = 8
+	[blockedloop(N, {4,2,1}, function(i,j)
+		return quote 
+			--IO.printf("%d %d\n",i,j)
+			a[i][j] = c
+			c = c + 1
+		end
+	end)]
+	for i = 0,N do
+		for j = 0,N do
+			IO.printf("%d\t",a[i][j])
+		end
+		IO.printf("\n")
+	end
+end
+
+main()
+
+
+
+function Image(Spectrum)
+	local struct ImageImpl {
+		data : &Spectrum,
+		N : int
+	}
+	terra ImageImpl:init(N : int)
+		self.data = [&float](stdlib.malloc(N*N*sizeof(Spectrum)))
+		self.N = N
+	end
+	ImageImpl.methods.pixel = macro(function(self,x,y)
+		return `self.data[x*self.N + y]
+	end)
+	return ImageImpl
+end
+
+GreyScaleImage = Image(float)
+
+terra laplace(input : &GreyScaleImage, output : &GreyScaleImage)
+	var newN = input.N - 2 --shrink result since we do not calculate boundaries
+	output:init(newN);
+	[blockedloop(newN,{32,1},function(i,j)
+		return quote
+			output:pixel(i,j) =
+              input:pixel(i+0,j+1)
+            + input:pixel(i+2,j+1)
+            + input:pixel(i+1,j+2)
+            + input:pixel(i+1,j+0)
+            - 4 * input:pixel(i+1,j+1)
+		end
+	end)]
+end
+
+laplace:compile()
+laplace:printpretty()