samples: add Terra samples

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

samples/Terra/cudatest.t

@@ -0,0 +1,47 @@
+if not terralib.cudacompile then
+	print("CUDA not enabled, not performing test...")
+	return
+end
+
+local tid = cudalib.nvvm_read_ptx_sreg_tid_x--terralib.intrinsic("llvm.nvvm.read.ptx.sreg.tid.x",{} -> int)
+local ntid = cudalib.nvvm_read_ptx_sreg_ntid_x -- terralib.intrinsic("llvm.nvvm.read.ptx.sreg.ntid.x",{} -> int)
+
+fn = terra(result : &float)
+    var t = tid()
+	result[t] = t
+end
+fn:setinlined(false)
+--our very simple cuda kernel
+--more work needs to be done to expose the right CUDA intrinsics
+--to do more compilicated things
+foo = terra(result : &float)
+    fn(result)
+end
+
+terralib.includepath = terralib.includepath..";/usr/local/cuda/include"
+
+local C = terralib.includecstring [[
+#include "cuda_runtime.h"
+#include <stdlib.h>
+#include <stdio.h>
+]]
+local R = terralib.cudacompile({ bar = foo })
+
+terra doit(N : int)
+	var data : &float
+	C.cudaMalloc([&&opaque](&data),sizeof(float)*N)
+	var launch = terralib.CUDAParams { 1,1,1, N,1,1, 0, nil }
+	R.bar(&launch,data)
+	var results : &float = [&float](C.malloc(sizeof(float)*N))
+	C.cudaMemcpy(results,data,sizeof(float)*N,2)
+	var result = 0.f
+	for i = 0,N do
+		result = result + results[i]
+	end
+	return result
+end
+
+local test = require("test")
+local N = 16
+local expected = (N - 1)*N/2
+test.eq(doit(N),expected)