diff options
Diffstat (limited to 'src/gpgpu-sim/addrdec.cc')
| -rw-r--r-- | src/gpgpu-sim/addrdec.cc | 102 |
1 files changed, 49 insertions, 53 deletions
diff --git a/src/gpgpu-sim/addrdec.cc b/src/gpgpu-sim/addrdec.cc index 655d790..19714ec 100644 --- a/src/gpgpu-sim/addrdec.cc +++ b/src/gpgpu-sim/addrdec.cc @@ -27,12 +27,16 @@ // POSSIBILITY OF SUCH DAMAGE. #include "addrdec.h" +#include <math.h> #include <string.h> #include "../option_parser.h" #include "gpu-sim.h" +#include "hashing.h" static long int powli(long int x, long int y); static unsigned int LOGB2_32(unsigned int v); +static unsigned next_powerOf2(unsigned n); + static new_addr_type addrdec_packbits(new_addr_type mask, new_addr_type val, unsigned char high, unsigned char low); static void addrdec_getmasklimit(new_addr_type mask, unsigned char *high, @@ -65,7 +69,8 @@ void linear_to_raw_address_translation::addrdec_setoption(option_parser_t opp) { "= new add. mask + flipped bank sel and chip sel bits", "0"); option_parser_register( - opp, "-memory_partition_indexing", OPT_UINT32, &memory_partition_indexing, + opp, "-gpgpu_memory_partition_indexing", OPT_UINT32, + &memory_partition_indexing, "0 = no indexing, 1 = bitwise xoring, 2 = IPoly, 3 = custom indexing", "0"); } @@ -89,7 +94,7 @@ new_addr_type linear_to_raw_address_translation::partition_address( void linear_to_raw_address_translation::addrdec_tlx(new_addr_type addr, addrdec_t *tlx) const { - unsigned long long int addr_for_chip, rest_of_addr; + unsigned long long int addr_for_chip, rest_of_addr, rest_of_addr_high_bits; if (!gap) { tlx->chip = addrdec_packbits(addrdec_mask[CHIP], addr, addrdec_mkhigh[CHIP], addrdec_mklow[CHIP]); @@ -101,6 +106,9 @@ void linear_to_raw_address_translation::addrdec_tlx(new_addr_type addr, addrdec_mklow[COL]); tlx->burst = addrdec_packbits(addrdec_mask[BURST], addr, addrdec_mkhigh[BURST], addrdec_mklow[BURST]); + rest_of_addr_high_bits = + (addr >> (ADDR_CHIP_S + (log2channel + log2sub_partition))); + } else { // Split the given address at ADDR_CHIP_S into (MSBs,LSBs) // - extract chip address using modulus of MSBs @@ -108,6 +116,7 @@ void linear_to_raw_address_translation::addrdec_tlx(new_addr_type addr, // the LSBs addr_for_chip = (addr >> ADDR_CHIP_S) % m_n_channel; rest_of_addr = ((addr >> ADDR_CHIP_S) / m_n_channel) << ADDR_CHIP_S; + rest_of_addr_high_bits = ((addr >> ADDR_CHIP_S) / m_n_channel); rest_of_addr |= addr & ((1 << ADDR_CHIP_S) - 1); tlx->chip = addr_for_chip; @@ -127,68 +136,35 @@ void linear_to_raw_address_translation::addrdec_tlx(new_addr_type addr, break; case BITWISE_PERMUTATION: { assert(!gap); - tlx->chip = (tlx->chip) ^ (tlx->row & (m_n_channel - 1)); + tlx->chip = + bitwise_hash_function(rest_of_addr_high_bits, tlx->chip, m_n_channel); assert(tlx->chip < m_n_channel); break; } case IPOLY: { - /* - * Set Indexing function from "Pseudo-randomly interleaved memory." - * Rau, B. R et al. - * ISCA 1991 - * - * equations are adopted from: - * "Sacat: streaming-aware conflict-avoiding thrashing-resistant gpgpu - * cache management scheme." Khairy et al. IEEE TPDS 2017. - */ - if (m_n_channel == 32) { - std::bitset<64> a(tlx->row); - std::bitset<5> chip(tlx->chip); - chip[0] = a[13] ^ a[12] ^ a[11] ^ a[10] ^ a[9] ^ a[6] ^ a[5] ^ a[3] ^ - a[0] ^ chip[0]; - chip[1] = a[14] ^ a[13] ^ a[12] ^ a[11] ^ a[10] ^ a[7] ^ a[6] ^ a[4] ^ - a[1] ^ chip[1]; - chip[2] = a[14] ^ a[10] ^ a[9] ^ a[8] ^ a[7] ^ a[6] ^ a[3] ^ a[2] ^ - a[0] ^ chip[2]; - chip[3] = - a[11] ^ a[10] ^ a[9] ^ a[8] ^ a[7] ^ a[4] ^ a[3] ^ a[1] ^ chip[3]; - chip[4] = - a[12] ^ a[11] ^ a[10] ^ a[9] ^ a[8] ^ a[5] ^ a[4] ^ a[2] ^ chip[4]; - tlx->chip = chip.to_ulong(); + // assert(!gap); + unsigned sub_partition_addr_mask = m_n_sub_partition_in_channel - 1; + unsigned sub_partition = tlx->chip * m_n_sub_partition_in_channel + + (tlx->bk & sub_partition_addr_mask); + sub_partition = ipoly_hash_function( + rest_of_addr_high_bits, sub_partition, + nextPowerOf2_m_n_channel * m_n_sub_partition_in_channel); - } else { /* Else incorrect number of channels for the hashing function */ - assert( - "\nGPGPU-Sim memory_partition_indexing error: The number of " - "channels should be " - "32 for the hashing IPOLY index function.\n" && - 0); - } - assert(tlx->chip < m_n_channel); - break; - } - case PAE: { - // Page Address Entropy - // random selected bits from the page and bank bits - // similar to - // Liu, Yuxi, et al. "Get Out of the Valley: Power-Efficient Address - // Mapping for GPUs." ISCA 2018 - std::bitset<64> a(tlx->row); - std::bitset<5> chip(tlx->chip); - std::bitset<4> b(tlx->bk); - chip[0] = a[13] ^ a[10] ^ a[9] ^ a[5] ^ a[0] ^ b[3] ^ b[0] ^ chip[0]; - chip[1] = a[12] ^ a[11] ^ a[6] ^ a[1] ^ b[3] ^ b[2] ^ b[1] ^ chip[1]; - chip[2] = a[14] ^ a[9] ^ a[8] ^ a[7] ^ a[2] ^ b[1] ^ chip[2]; - chip[3] = a[11] ^ a[10] ^ a[8] ^ a[3] ^ b[2] ^ b[3] ^ chip[3]; - chip[4] = a[12] ^ a[9] ^ a[8] ^ a[5] ^ a[4] ^ b[1] ^ b[0] ^ chip[4]; - tlx->chip = chip.to_ulong(); + if (gap) // if it is not 2^n partitions, then take modular + sub_partition = + sub_partition % (m_n_channel * m_n_sub_partition_in_channel); + + tlx->chip = sub_partition / m_n_sub_partition_in_channel; + tlx->sub_partition = sub_partition; assert(tlx->chip < m_n_channel); + assert(tlx->sub_partition < m_n_channel * m_n_sub_partition_in_channel); + return; break; } case RANDOM: { // This is an unrealistic hashing using software hashtable // we generate a random set for each memory address and save the value in - // a big hashtable for future reuse - new_addr_type chip_address = (addr >> ADDR_CHIP_S); + new_addr_type chip_address = (addr >> (ADDR_CHIP_S - log2sub_partition)); tr1_hash_map<new_addr_type, unsigned>::const_iterator got = address_random_interleaving.find(chip_address); if (got == address_random_interleaving.end()) { @@ -308,8 +284,12 @@ void linear_to_raw_address_translation::init( unsigned i; unsigned long long int mask; unsigned int nchipbits = ::LOGB2_32(n_channel); + log2channel = nchipbits; + log2sub_partition = ::LOGB2_32(n_sub_partition_in_channel); m_n_channel = n_channel; m_n_sub_partition_in_channel = n_sub_partition_in_channel; + nextPowerOf2_m_n_channel = ::next_powerOf2(n_channel); + m_n_sub_partition_total = n_channel * n_sub_partition_in_channel; gap = (n_channel - ::powli(2, nchipbits)); if (gap) { @@ -596,6 +576,22 @@ static unsigned int LOGB2_32(unsigned int v) { return r; } +// compute power of two greater than or equal to n +// https://www.techiedelight.com/round-next-highest-power-2/ +unsigned next_powerOf2(unsigned n) { + // decrement n (to handle the case when n itself + // is a power of 2) + n = n - 1; + + // do till only one bit is left + while (n & n - 1) n = n & (n - 1); // unset rightmost bit + + // n is now a power of two (less than n) + + // return next power of 2 + return n << 1; +} + static new_addr_type addrdec_packbits(new_addr_type mask, new_addr_type val, unsigned char high, unsigned char low) { unsigned pos = 0; |