samples: add Terra samples

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

samples/Terra/stencil.t

@@ -0,0 +1,134 @@
+
+local C = terralib.includecstring [[
+#include<stdio.h>
+#include<stdlib.h>
+#ifndef _WIN32
+#include <sys/time.h>
+static double CurrentTimeInSeconds() {
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return tv.tv_sec + tv.tv_usec / 1000000.0;
+}
+#else
+#include <time.h>
+static double CurrentTimeInSeconds() {
+	return time(NULL);
+}
+#endif
+
+int CalcTime(int * times, double * start) {
+	if(*times == 0) {
+		*start = CurrentTimeInSeconds();
+	} else {
+		double elapsed = CurrentTimeInSeconds() - *start;
+		if(elapsed > 0.1f && *times >= 3) {
+			*start = elapsed / *times;
+			return 0;
+		}
+	}
+	(*times)++;
+	return 1;
+}
+]]
+
+
+function symmat(name,I,...)
+	if not I then return symbol(name) end
+	local r = {}
+	for i = 0,I-1 do
+		r[i] = symmat(name..tostring(i),...)
+	end
+	return r
+end
+
+
+
+local IO = terralib.includec("stdio.h")
+
+
+
+NI,NJ = 1,4
+V = 8
+terra uload(d : &float)
+	return terralib.attrload([&vector(float,V)](d), { align = 4 })
+end
+terra ustore(d : &float, v : vector(float,V))
+	terralib.attrstore([&vector(float,V)](d), v, { align = 4 })
+end
+
+terra runit(N : int, input : &float, output : &float)
+	input = input + N*NI + V*NJ
+	output = output + N*NI + V*NJ
+	for i = NI, N-NI,NI do
+		for j = V*NJ, N-V*NJ,V*NJ do
+			[(function()
+				local C = symmat("C",NI,NJ)
+				local stmts = terralib.newlist()
+				for iii = 0,NI-1 do for jjj = 0,NJ-1 do 
+					stmts:insert(quote 
+						var [C[iii][jjj]] : vector(float,V) = 0
+					end) 
+				end end
+
+				for ii = -1,1 do
+					for jj = -1,1 do
+						for iii = 0,NI-1 do for jjj = 0,NJ-1 do
+							if math.abs(ii) + math.abs(jj) ~= 2 then
+								stmts:insert(quote
+									var d = uload(input + N * (ii + iii) + jj + V*jjj);
+									[C[iii][jjj]] = [C[iii][jjj]] + d
+								end)
+							end
+						end end
+					end
+				end
+				for iii = 0,NI-1 do for jjj = 0,NJ-1 do 
+					stmts:insert(quote 
+						ustore(output + N * (iii) + V*jjj, [C[iii][jjj]])
+					end) 
+				end end
+				return stmts
+			end)()]
+			input = input + V*NJ
+			output = output + V*NJ
+		end
+		input = input + 2*V*NJ
+		output = output + 2*V*NJ
+	end
+end
+
+terra doit()
+	var N = 2048
+	var img = [&float](C.malloc(N*N*sizeof(float)))
+	var img2 = [&float](C.malloc(N*N*sizeof(float)))
+
+	for i = 0, N do
+		for j = 0, N do
+			img[i*N+j] = 1
+		end
+	end
+
+	var times  = 0
+	var mytime : double
+	while C.CalcTime(&times,&mytime) ~= 0 do
+		runit(N,img,img2)
+	end
+
+	C.printf("times = %d\n",times)
+	for i = NI, N-NI do
+		for j = V*NJ, N-V*NJ do
+			if img2[i*N+j] ~= 5 then
+				C.printf("wrong! %d %d %f\n",i,j,img2[i*N+j])
+				goto out
+			end
+		end
+	end
+	::out::
+	var togiga = 1.0/(1024*1024*1024)
+	var pixels = (N-NI)*(N-V*NJ)
+	C.printf("%f %f %f\n", mytime, pixels*4*2 *togiga / mytime, 5*pixels * togiga / mytime)
+
+end
+doit()
+runit:disas()
+doit()