fixing the IPOLY L2 and Dram indexing

1 files changed, 24 insertions, 1 deletions

diff --git a/src/gpgpu-sim/dram.cc b/src/gpgpu-sim/dram.cc
index 9c33822..a056371 100644
--- a/src/gpgpu-sim/dram.cc
+++ b/src/gpgpu-sim/dram.cc
@@ -210,10 +210,33 @@ dram_req_t::dram_req_t( class mem_fetch *mf, unsigned banks, unsigned dram_bnk_i
 		case BITWISE_XORING_BK_INDEX:
 		{
 			//xoring bank bits with lower bits of the page
-			int lbank = log2(banks);
+			int lbank = LOGB2(banks);
 			bk  = tlx.bk ^ (tlx.row & ((1<<lbank)-1));
 			break;
 		}
+		case IPOLY_BK_INDEX:
+		{
+			/*IPOLY for bank indexing function from "Pseudo-randomly interleaved memory."
+			 * Rau, B. R et al.
+			 * ISCA 1991
+			 * http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=348DEA37A3E440473B3C075EAABC63B6?doi=10.1.1.12.7149&rep=rep1&type=pdf
+			 */
+			if (banks == 16) {
+				std::bitset<64> a(tlx.row);
+				std::bitset<4> b(tlx.bk);
+				b[0] = a[11]^a[10]^a[9]^a[8]^a[6]^a[4]^a[3]^a[0]^b[0];
+				b[1] = a[12]^a[8]^a[7]^a[6]^a[5]^a[3]^a[1]^a[0]^b[1];
+				b[2] = a[9]^a[8]^a[7]^a[6]^a[4]^a[2]^a[1]^b[2];
+				b[3] = a[10]^a[9]^a[8]^a[7]^a[5]^a[3]^a[2]^b[3];
+				bk = b.to_ulong();
+				assert(bk < banks);
+			}
+			else{ /* Else incorrect number of channels for the hashing function */
+				assert("\nGPGPU-Sim memory_banking indexing error: The number of banks should be "
+						"16 for the hashing IPOLY index function.\n" && 0);
+			}
+			break;
+		}
 		case CUSTOM_BK_INDEX:
 	        /* No custom set function implemented */
 			//Do you custom index here