Subzero: Speed up VariablesMetadata initialization.
Currently, O2 calls VariablesMetadata::init() 4 times:
- Twice for liveness analysis, where only multi-block use information is needed for dealing with sparse bit vectors.
- Once for address mode inference, where single-definition information is needed.
- Once for register allocation, where all information is needed, including the set of all definitions which is needed for determining AllowOverlap.
So we limit the amount of data we gather based on the actual need.
BUG= none
R=jvoung@chromium.org
Review URL: https://codereview.chromium.org/650613003
diff --git a/src/IceOperand.cpp b/src/IceOperand.cpp
index 3f7d0bf..3285e6d 100644
--- a/src/IceOperand.cpp
+++ b/src/IceOperand.cpp
@@ -185,8 +185,10 @@
return V;
}
-void VariableTracking::markUse(const Inst *Instr, const CfgNode *Node,
- bool IsFromDef, bool IsImplicit) {
+void VariableTracking::markUse(MetadataKind TrackingKind, const Inst *Instr,
+ const CfgNode *Node, bool IsFromDef,
+ bool IsImplicit) {
+ (void)TrackingKind;
if (MultiBlock == MBS_MultiBlock)
return;
// TODO(stichnot): If the use occurs as a source operand in the
@@ -227,19 +229,31 @@
}
}
-void VariableTracking::markDef(const Inst *Instr, const CfgNode *Node) {
+void VariableTracking::markDef(MetadataKind TrackingKind, const Inst *Instr,
+ const CfgNode *Node) {
// TODO(stichnot): If the definition occurs in the last instruction
// of the block, consider not marking this as a separate use. But
// be careful not to omit all uses of the variable if markDef() and
// markUse() both use this optimization.
assert(Node);
// Verify that instructions are added in increasing order.
- assert(Definitions.empty() ||
- Instr->getNumber() >= Definitions.back()->getNumber());
- Definitions.push_back(Instr);
+#ifndef NDEBUG
+ if (TrackingKind == VMK_All) {
+ const Inst *LastInstruction =
+ Definitions.empty() ? FirstOrSingleDefinition : Definitions.back();
+ assert(LastInstruction == NULL ||
+ Instr->getNumber() >= LastInstruction->getNumber());
+ }
+#endif
const bool IsFromDef = true;
const bool IsImplicit = false;
- markUse(Instr, Node, IsFromDef, IsImplicit);
+ markUse(TrackingKind, Instr, Node, IsFromDef, IsImplicit);
+ if (TrackingKind == VMK_Uses)
+ return;
+ if (FirstOrSingleDefinition == NULL)
+ FirstOrSingleDefinition = Instr;
+ else if (TrackingKind == VMK_All)
+ Definitions.push_back(Instr);
switch (MultiDef) {
case MDS_Unknown:
assert(SingleDefNode == NULL);
@@ -275,8 +289,8 @@
return NULL;
case MDS_SingleDef:
case MDS_MultiDefSingleBlock:
- assert(!Definitions.empty());
- return Definitions[0];
+ assert(FirstOrSingleDefinition);
+ return FirstOrSingleDefinition;
}
}
@@ -287,13 +301,14 @@
case MDS_MultiDefSingleBlock:
return NULL;
case MDS_SingleDef:
- assert(!Definitions.empty());
- return Definitions[0];
+ assert(FirstOrSingleDefinition);
+ return FirstOrSingleDefinition;
}
}
-void VariablesMetadata::init() {
+void VariablesMetadata::init(MetadataKind TrackingKind) {
TimerMarker T(TimerStack::TT_vmetadata, Func);
+ Kind = TrackingKind;
Metadata.clear();
Metadata.resize(Func->getNumVariables());
@@ -303,7 +318,8 @@
const CfgNode *EntryNode = Func->getEntryNode();
const bool IsFromDef = false;
const bool IsImplicit = true;
- Metadata[Var->getIndex()].markUse(NoInst, EntryNode, IsFromDef, IsImplicit);
+ Metadata[Var->getIndex()]
+ .markUse(Kind, NoInst, EntryNode, IsFromDef, IsImplicit);
}
for (CfgNode *Node : Func->getNodes()) {
@@ -318,14 +334,14 @@
Variable *Var = llvm::cast<Variable>(I->getSrc(SrcNum));
SizeT VarNum = Var->getIndex();
assert(VarNum < Metadata.size());
- Metadata[VarNum].markDef(Kill, Node);
+ Metadata[VarNum].markDef(Kind, Kill, Node);
}
continue; // no point in executing the rest
}
if (Variable *Dest = I->getDest()) {
SizeT DestNum = Dest->getIndex();
assert(DestNum < Metadata.size());
- Metadata[DestNum].markDef(I, Node);
+ Metadata[DestNum].markDef(Kind, I, Node);
}
for (SizeT SrcNum = 0; SrcNum < I->getSrcSize(); ++SrcNum) {
Operand *Src = I->getSrc(SrcNum);
@@ -336,7 +352,7 @@
assert(VarNum < Metadata.size());
const bool IsFromDef = false;
const bool IsImplicit = false;
- Metadata[VarNum].markUse(I, Node, IsFromDef, IsImplicit);
+ Metadata[VarNum].markUse(Kind, I, Node, IsFromDef, IsImplicit);
}
}
}
@@ -344,6 +360,7 @@
}
bool VariablesMetadata::isMultiDef(const Variable *Var) const {
+ assert(Kind != VMK_Uses);
if (Var->getIsArg())
return false;
if (!isTracked(Var))
@@ -364,6 +381,7 @@
}
const Inst *VariablesMetadata::getFirstDefinition(const Variable *Var) const {
+ assert(Kind != VMK_Uses);
if (!isTracked(Var))
return NULL; // conservative answer
SizeT VarNum = Var->getIndex();
@@ -371,6 +389,7 @@
}
const Inst *VariablesMetadata::getSingleDefinition(const Variable *Var) const {
+ assert(Kind != VMK_Uses);
if (!isTracked(Var))
return NULL; // conservative answer
SizeT VarNum = Var->getIndex();
@@ -378,11 +397,12 @@
}
const InstDefList &
-VariablesMetadata::getDefinitions(const Variable *Var) const {
+VariablesMetadata::getLatterDefinitions(const Variable *Var) const {
+ assert(Kind == VMK_All);
if (!isTracked(Var))
return NoDefinitions;
SizeT VarNum = Var->getIndex();
- return Metadata[VarNum].getDefinitions();
+ return Metadata[VarNum].getLatterDefinitions();
}
const CfgNode *VariablesMetadata::getLocalUseNode(const Variable *Var) const {
