add built-in function "atan2"

also improve the accuracy of built-in function "atan"
also add a test case

Signed-off-by: Homer Hsing <homer.xing@intel.com>
Reviewed-by: "Yang, Rong R" <rong.r.yang@intel.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/utests/builtin_atan2.cpp b/utests/builtin_atan2.cpp
new file mode 100644
index 00000000..29dd7b45
--- /dev/null
+++ b/utests/builtin_atan2.cpp
@@ -0,0 +1,43 @@
+#include <cmath>
+#include "utest_helper.hpp"
+
+void builtin_atan2(void) {
+	const int n = 1024;
+	float y[n], x[n];
+
+	// Setup kernel and buffers
+	OCL_CREATE_KERNEL("builtin_atan2");
+	OCL_CREATE_BUFFER(buf[0], 0, n * sizeof(float), NULL);
+	OCL_CREATE_BUFFER(buf[1], 0, n * sizeof(float), NULL);
+	OCL_CREATE_BUFFER(buf[2], 0, n * sizeof(float), NULL);
+	OCL_SET_ARG(0, sizeof(cl_mem), &buf[0]);
+	OCL_SET_ARG(1, sizeof(cl_mem), &buf[1]);
+	OCL_SET_ARG(2, sizeof(cl_mem), &buf[2]);
+	globals[0] = n;
+	locals[0] = 16;
+
+	OCL_MAP_BUFFER(0);
+	OCL_MAP_BUFFER(1);
+	for (int i = 0; i < n; ++i) {
+		y[i] = ((float*) buf_data[0])[i] = (rand()&255) * 0.01f;
+		x[i] = ((float*) buf_data[1])[i] = (rand()&255) * 0.01f;
+	}
+	OCL_UNMAP_BUFFER(0);
+	OCL_UNMAP_BUFFER(1);
+
+	OCL_NDRANGE(1);
+
+	OCL_MAP_BUFFER(2);
+	float *dst = (float*) buf_data[2];
+	for (int i = 0; i < n; ++i) {
+		float cpu = atan2f(y[i], x[i]);
+		float gpu = dst[i];
+		if (fabsf(cpu - gpu) >= 1e-2) {
+			printf("%f %f %f %f\n", y[i], x[i], cpu, gpu);
+			OCL_ASSERT(0);
+		}
+	}
+	OCL_UNMAP_BUFFER(2);
+}
+
+MAKE_UTEST_FROM_FUNCTION (builtin_atan2);