[doc] Added java docs for FPGA attribute default numbers
@@ -53,7 +53,19 @@ import static org.graalvm.compiler.nodes.loop.DefaultLoopPolicies.Options.FullUn
public class TornadoFPGAPragmas extends BasePhase<TornadoHighTierContext> {
+ /*
+ * The default factor number for loop unrolling is 4, because this number
+ * yielded higher performance on Intel FPGAs.
+ */
private static final int UNROLL_FACTOR_NUMBER = 4;
+ /**
+ * The default initiation interval number for loop pipelining is 1, because this
+ * number has been indicated as the default by Xilinx HLS for full pipelining.
+ *
+ * @see <a href=
+ * "https://www.xilinx.com/html_docs/xilinx2020_2/vitis_doc/openclattributes.html#sgo1504034359903__ad410982"
+ * * >Vitis 2020.2 Documentation</a>.
+ */
private static final int XILINX_PIPELINING_II_NUMBER = 1;
private TornadoDeviceContext deviceContext;
