diff options
Diffstat (limited to 'src/cuda-sim/instructions.cc')
| -rw-r--r-- | src/cuda-sim/instructions.cc | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/src/cuda-sim/instructions.cc b/src/cuda-sim/instructions.cc index 3b938bb..bb15621 100644 --- a/src/cuda-sim/instructions.cc +++ b/src/cuda-sim/instructions.cc @@ -1458,6 +1458,26 @@ void breakaddr_impl( const ptx_instruction *pI, ptx_thread_info *thread ) void brev_impl( const ptx_instruction *pI, ptx_thread_info *thread ) { inst_not_implemented(pI); } void brkpt_impl( const ptx_instruction *pI, ptx_thread_info *thread ) { inst_not_implemented(pI); } +unsigned trunc(unsigned num, unsigned precision) { + int mask = 1, latest_one = -1; + unsigned data = num; + for (unsigned j = 0; j < sizeof(unsigned)*8; j++) { + int bit = data & mask; + if (bit == 1) latest_one = j; + data >>= 1; + } + if (latest_one >= precision) { + // round_up is 1 if the most significant truncated digit is a 1, otherwise it is 0 + //int round_up = (num & (1 << (latest_one-precision))) >> (latest_one-precision); + //unsigned shifted_output = num >> (latest_one-precision+1); + // if shifted_output is a number like 1111, don't round up + //if (shifted_output == (pow(2,precision)-1)) round_up = 0; + //num = shifted_output + round_up; + num >>= (latest_one-precision+1); + } + return num; +} + void bsmad_impl( const ptx_instruction *pI, core_t *core, warp_inst_t inst ) { // operands: @@ -1530,16 +1550,18 @@ void bsmad_impl( const ptx_instruction *pI, core_t *core, warp_inst_t inst ) int sum = 0; unsigned mask = (unsigned)(pow(2,ip)-1) << (pos*ip); for (int j = 0; j < THREADS; j++) { - sum += ((mask & buffer[j][buf]) >> (pos*ip)) * synapse[j]; + //sum += ((mask & buffer[j][buf]) >> (pos*ip)) * synapse[j]; + sum += trunc(((mask & buffer[j][buf]) >> (pos*ip)) * synapse[j], op); } // get the previous output mask = (unsigned)(pow(2,op)-1) << (op*(i-buffer_data_start)); int past_output = (mask & output) >> (op*(i-buffer_data_start)); - unpacked_output[i-buffer_data_start] = sum + past_output; + unpacked_output[i-buffer_data_start] = trunc(trunc(sum,op) + past_output,op); + // truncate sum, truncate (truncated sum + past_output) } // truncate output - for (unsigned i = 0; i < 32/op; i++) { + /*for (unsigned i = 0; i < 32/op; i++) { int mask = 1, latest_one = -1; unsigned data = unpacked_output[i]; for (unsigned j = 0; j < sizeof(unsigned)*8; j++) { @@ -1555,7 +1577,7 @@ void bsmad_impl( const ptx_instruction *pI, core_t *core, warp_inst_t inst ) if (shifted_output == (pow(2,op)-1)) round_up = 0; unpacked_output[i] = shifted_output + round_up; } - } + }*/ // pack the outputs into one register unsigned mask = pow(2,op)-1; |