This improves the variable use weight by taking into account use in loops. It
further improves spec2k performance and fixes the regression in ammp. Loops are
identified using an extension to Tarjan's algorithm.
BUG=
R=stichnot@chromium.org
Review URL: https://codereview.chromium.org/1318553003.
diff --git a/src/IceCfgNode.cpp b/src/IceCfgNode.cpp
index 4199c41..095994e 100644
--- a/src/IceCfgNode.cpp
+++ b/src/IceCfgNode.cpp
@@ -219,6 +219,11 @@
// not contain duplicates.
CfgNode *CfgNode::splitIncomingEdge(CfgNode *Pred, SizeT EdgeIndex) {
CfgNode *NewNode = Func->makeNode();
+ // Depth is the minimum as it works if both are the same, but if one is
+ // outside the loop and the other is inside, the new node should be placed
+ // outside and not be executed multiple times within the loop.
+ NewNode->setLoopNestDepth(
+ std::min(getLoopNestDepth(), Pred->getLoopNestDepth()));
if (BuildDefs::dump())
NewNode->setName("split_" + Pred->getName() + "_" + getName() + "_" +
std::to_string(EdgeIndex));
@@ -1175,9 +1180,11 @@
Func->setCurrentNode(this);
Ostream &Str = Func->getContext()->getStrDump();
Liveness *Liveness = Func->getLiveness();
- if (Func->isVerbose(IceV_Instructions)) {
+ if (Func->isVerbose(IceV_Instructions) || Func->isVerbose(IceV_Loop))
Str << getName() << ":\n";
- }
+ // Dump the loop nest depth
+ if (Func->isVerbose(IceV_Loop))
+ Str << " // LoopNestDepth = " << getLoopNestDepth() << "\n";
// Dump list of predecessor nodes.
if (Func->isVerbose(IceV_Preds) && !InEdges.empty()) {
Str << " // preds = ";
