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cpu, probe: Fix elastic trace register dependency

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Change-Id: I017852eac183fac3f914fdb96d7e72a56ea9d682
Reviewed-by: Nathanael Premillieu <nathanael.premillieu@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5121
Reviewed-by: Matthias Jung <jungma@eit.uni-kl.de>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
This commit is contained in:
Radhika Jagtap
2017-09-21 17:24:09 +01:00
committed by Andreas Sandberg
parent 85960074a1
commit ed969daf1a
1 changed files with 24 additions and 16 deletions
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40
src/cpu/o3/probe/elastic_trace.cc
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@@ -238,23 +238,31 @@ ElasticTrace::updateRegDep(const DynInstPtr &dyn_inst)
// dependency on the last writer.
int8_t max_regs = dyn_inst->numSrcRegs();
for (int src_idx = 0; src_idx < max_regs; src_idx++) {
// Get the physical register index of the i'th source register.
PhysRegIdPtr src_reg = dyn_inst->renamedSrcRegIdx(src_idx);
DPRINTFR(ElasticTrace, "[sn:%lli] Check map for src reg"
" %i (%s)\n", seq_num,
src_reg->index(), src_reg->className());
auto itr_last_writer = physRegDepMap.find(src_reg->flatIndex());
if (itr_last_writer != physRegDepMap.end()) {
InstSeqNum last_writer = itr_last_writer->second;
// Additionally the dependency distance is kept less than the window
// size parameter to limit the memory allocation to nodes in the
// graph. If the window were tending to infinite we would have to
// load a large number of node objects during replay.
if (seq_num - last_writer < depWindowSize) {
// Record a physical register dependency.
exec_info_ptr->physRegDepSet.insert(last_writer);
const RegId& src_reg = dyn_inst->srcRegIdx(src_idx);
if (!src_reg.isMiscReg() &&
!src_reg.isZeroReg()) {
// Get the physical register index of the i'th source register.
PhysRegIdPtr phys_src_reg = dyn_inst->renamedSrcRegIdx(src_idx);
DPRINTFR(ElasticTrace, "[sn:%lli] Check map for src reg"
" %i (%s)\n", seq_num,
phys_src_reg->flatIndex(), phys_src_reg->className());
auto itr_writer = physRegDepMap.find(phys_src_reg->flatIndex());
if (itr_writer != physRegDepMap.end()) {
InstSeqNum last_writer = itr_writer->second;
// Additionally the dependency distance is kept less than the
// window size parameter to limit the memory allocation to
// nodes in the graph. If the window were tending to infinite
// we would have to load a large number of node objects during
// replay.
if (seq_num - last_writer < depWindowSize) {
// Record a physical register dependency.
exec_info_ptr->physRegDepSet.insert(last_writer);
}
}
}
}
// Loop through the destination registers of this instruction and update
@@ -270,7 +278,7 @@ ElasticTrace::updateRegDep(const DynInstPtr &dyn_inst)
// register.
PhysRegIdPtr phys_dest_reg = dyn_inst->renamedDestRegIdx(dest_idx);
DPRINTFR(ElasticTrace, "[sn:%lli] Update map for dest reg"
" %i (%s)\n", seq_num, dest_reg.index(),
" %i (%s)\n", seq_num, phys_dest_reg->flatIndex(),
dest_reg.className());
physRegDepMap[phys_dest_reg->flatIndex()] = seq_num;
}