maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Don't charge full latency for an anti-dependence, in this simplistic 

pipeline model.

llvm-svn: 60733
This commit is contained in:
Dan Gohman 2008-12-09 00:26:46 +00:00
parent 08134c984b
commit 37c496979c
1 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
llvm/lib/CodeGen/LatencyPriorityQueue.cpp
View File

@ -52,8 +52,9 @@ int LatencyPriorityQueue::CalcLatency(const SUnit &SU) {
WorkList.push_back(&SU);
while (!WorkList.empty()) {
const SUnit *Cur = WorkList.back();
unsigned CurLatency = Cur->Latency;
bool AllDone = true;
int MaxSuccLatency = 0;
unsigned MaxSuccLatency = 0;
for (SUnit::const_succ_iterator I = Cur->Succs.begin(),E = Cur->Succs.end();
I != E; ++I) {
int SuccLatency = Latencies[I->Dep->NodeNum];
@ -61,11 +62,14 @@ int LatencyPriorityQueue::CalcLatency(const SUnit &SU) {
AllDone = false;
WorkList.push_back(I->Dep);
} else {
MaxSuccLatency = std::max(MaxSuccLatency, SuccLatency);
// This assumes that there's no delay for reusing registers.
unsigned NewLatency =
SuccLatency + ((I->isCtrl && I->Reg != 0) ? 1 : CurLatency);
MaxSuccLatency = std::max(MaxSuccLatency, NewLatency);
}
}
if (AllDone) {
Latencies[Cur->NodeNum] = MaxSuccLatency + Cur->Latency;
Latencies[Cur->NodeNum] = MaxSuccLatency;
WorkList.pop_back();
}
}