diff options
| -rw-r--r-- | CHANGES | 3 | ||||
| -rw-r--r-- | src/abstract_hardware_model.cc | 77 | ||||
| -rw-r--r-- | src/abstract_hardware_model.h | 2 |
3 files changed, 54 insertions, 28 deletions
@@ -1,4 +1,7 @@ LOG: +Version 3.2.3+edits (development branch) versus 3.2.3 +- Fixed bug #81, fix ordering of pushing branch entries to the stack + Version 3.2.3 versus 3.2.2 - Fixed bug #78, added signed types to implementation of slct instruction. - Fixed bug #64, properly handing unsigned add. diff --git a/src/abstract_hardware_model.cc b/src/abstract_hardware_model.cc index 5ba0270..cd4e8d7 100644 --- a/src/abstract_hardware_model.cc +++ b/src/abstract_hardware_model.cc @@ -632,7 +632,7 @@ void simt_stack::print (FILE *fout) const } } -void simt_stack::update( simt_mask_t &thread_done, addr_vector_t &next_pc, address_type recvg_pc, op_type next_inst_op ) +void simt_stack::update( simt_mask_t &thread_done, addr_vector_t &next_pc, address_type recvg_pc, op_type next_inst_op,unsigned next_inst_size, address_type next_inst_pc ) { assert(m_stack.size() > 0); @@ -642,12 +642,15 @@ void simt_stack::update( simt_mask_t &thread_done, addr_vector_t &next_pc, addre address_type top_recvg_pc = m_stack.back().m_recvg_pc; address_type top_pc = m_stack.back().m_pc; // the pc of the instruction just executed stack_entry_type top_type = m_stack.back().m_type; - + assert(top_pc==next_inst_pc); assert(top_active_mask.any()); const address_type null_pc = -1; bool warp_diverged = false; address_type new_recvg_pc = null_pc; + unsigned num_divergent_paths=0; + + std::map<address_type,simt_mask_t> divergent_paths; while (top_active_mask.any()) { // extract a group of threads with the same next PC among the active threads in the warp @@ -673,35 +676,55 @@ void simt_stack::update( simt_mask_t &thread_done, addr_vector_t &next_pc, addre continue; } - // HANDLE THE SPECIAL CASES FIRST - if (next_inst_op== CALL_OPS) - { - // Since call is not a divergent instruction, all threads should have executed a call instruction - assert(top_active_mask.any() == false); + divergent_paths[tmp_next_pc]=tmp_active_mask; + num_divergent_paths++; + } - simt_stack_entry new_stack_entry; - new_stack_entry.m_pc = tmp_next_pc; - new_stack_entry.m_active_mask = tmp_active_mask; - new_stack_entry.m_branch_div_cycle = gpu_sim_cycle+gpu_tot_sim_cycle; - new_stack_entry.m_type = STACK_ENTRY_TYPE_CALL; - m_stack.push_back(new_stack_entry); - return; - } else if(next_inst_op == RET_OPS && top_type==STACK_ENTRY_TYPE_CALL) { - // pop the CALL Entry - assert(top_active_mask.any() == false); - m_stack.pop_back(); + address_type not_taken_pc = next_inst_pc+next_inst_size; + assert(num_divergent_paths<=2); + for(unsigned i=0; i<num_divergent_paths; i++){ + address_type tmp_next_pc = null_pc; + simt_mask_t tmp_active_mask; + tmp_active_mask.reset(); + if(divergent_paths.find(not_taken_pc)!=divergent_paths.end()){ + assert(i==0); + tmp_next_pc=not_taken_pc; + tmp_active_mask=divergent_paths[tmp_next_pc]; + divergent_paths.erase(tmp_next_pc); + }else{ + std::map<address_type,simt_mask_t>:: iterator it=divergent_paths.begin(); + tmp_next_pc=it->first; + tmp_active_mask=divergent_paths[tmp_next_pc]; + divergent_paths.erase(tmp_next_pc); + } + + // HANDLE THE SPECIAL CASES FIRST + if (next_inst_op== CALL_OPS){ + // Since call is not a divergent instruction, all threads should have executed a call instruction + assert(num_divergent_paths == 1); - assert(m_stack.size() > 0); - m_stack.back().m_pc=tmp_next_pc;// set the PC of the stack top entry to return PC from the call stack; + simt_stack_entry new_stack_entry; + new_stack_entry.m_pc = tmp_next_pc; + new_stack_entry.m_active_mask = tmp_active_mask; + new_stack_entry.m_branch_div_cycle = gpu_sim_cycle+gpu_tot_sim_cycle; + new_stack_entry.m_type = STACK_ENTRY_TYPE_CALL; + m_stack.push_back(new_stack_entry); + return; + }else if(next_inst_op == RET_OPS && top_type==STACK_ENTRY_TYPE_CALL){ + // pop the CALL Entry + assert(num_divergent_paths == 1); + m_stack.pop_back(); + + assert(m_stack.size() > 0); + m_stack.back().m_pc=tmp_next_pc;// set the PC of the stack top entry to return PC from the call stack; // Check if the New top of the stack is reconverging - if (tmp_next_pc == m_stack.back().m_recvg_pc && m_stack.back().m_type!=STACK_ENTRY_TYPE_CALL) - { - assert(m_stack.back().m_type==STACK_ENTRY_TYPE_NORMAL); - m_stack.pop_back(); + if (tmp_next_pc == m_stack.back().m_recvg_pc && m_stack.back().m_type!=STACK_ENTRY_TYPE_CALL){ + assert(m_stack.back().m_type==STACK_ENTRY_TYPE_NORMAL); + m_stack.pop_back(); } return; - } + } // discard the new entry if its PC matches with reconvergence PC // that automatically reconverges the entry @@ -710,7 +733,7 @@ void simt_stack::update( simt_mask_t &thread_done, addr_vector_t &next_pc, addre // this new entry is not converging // if this entry does not include thread from the warp, divergence occurs - if (top_active_mask.any() && !warp_diverged ) { + if ((num_divergent_paths>1) && !warp_diverged ) { warp_diverged = true; // modify the existing top entry into a reconvergence entry in the pdom stack new_recvg_pc = recvg_pc; @@ -781,7 +804,7 @@ void core_t::updateSIMTStack(unsigned warpId, warp_inst_t * inst) next_pc.push_back( m_thread[wtid+i]->get_pc() ); } } - m_simt_stack[warpId]->update(thread_done,next_pc,inst->reconvergence_pc, inst->op); + m_simt_stack[warpId]->update(thread_done,next_pc,inst->reconvergence_pc, inst->op,inst->isize,inst->pc); } //! Get the warp to be executed using the data taken form the SIMT stack diff --git a/src/abstract_hardware_model.h b/src/abstract_hardware_model.h index a5b82ee..09b36ff 100644 --- a/src/abstract_hardware_model.h +++ b/src/abstract_hardware_model.h @@ -283,7 +283,7 @@ public: void reset(); void launch( address_type start_pc, const simt_mask_t &active_mask ); - void update( simt_mask_t &thread_done, addr_vector_t &next_pc, address_type recvg_pc, op_type next_inst_op ); + void update( simt_mask_t &thread_done, addr_vector_t &next_pc, address_type recvg_pc, op_type next_inst_op,unsigned next_inst_size, address_type next_inst_pc ); const simt_mask_t &get_active_mask() const; void get_pdom_stack_top_info( unsigned *pc, unsigned *rpc ) const; |