aboutsummaryrefslogtreecommitdiffstats
path: root/lib/CodeGen
diff options
context:
space:
mode:
Diffstat (limited to 'lib/CodeGen')
-rw-r--r--lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp68
-rw-r--r--lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h13
-rw-r--r--lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp7
3 files changed, 60 insertions, 28 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 969326c..bb94125 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1766,6 +1766,7 @@ void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B,
/// visitBitTestCase - this function produces one "bit test"
void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB,
MachineBasicBlock* NextMBB,
+ uint32_t BranchWeightToNext,
unsigned Reg,
BitTestCase &B,
MachineBasicBlock *SwitchBB) {
@@ -1803,8 +1804,10 @@ void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB,
ISD::SETNE);
}
- addSuccessorWithWeight(SwitchBB, B.TargetBB);
- addSuccessorWithWeight(SwitchBB, NextMBB);
+ // The branch weight from SwitchBB to B.TargetBB is B.ExtraWeight.
+ addSuccessorWithWeight(SwitchBB, B.TargetBB, B.ExtraWeight);
+ // The branch weight from SwitchBB to NextMBB is BranchWeightToNext.
+ addSuccessorWithWeight(SwitchBB, NextMBB, BranchWeightToNext);
SDValue BrAnd = DAG.getNode(ISD::BRCOND, getCurDebugLoc(),
MVT::Other, getControlRoot(),
@@ -1927,6 +1930,7 @@ bool SelectionDAGBuilder::handleSmallSwitchRange(CaseRec& CR,
if (++BBI != FuncInfo.MF->end())
NextBlock = BBI;
+ BranchProbabilityInfo *BPI = FuncInfo.BPI;
// If any two of the cases has the same destination, and if one value
// is the same as the other, but has one bit unset that the other has set,
// use bit manipulation to do two compares at once. For example:
@@ -1960,8 +1964,12 @@ bool SelectionDAGBuilder::handleSmallSwitchRange(CaseRec& CR,
ISD::SETEQ);
// Update successor info.
- addSuccessorWithWeight(SwitchBB, Small.BB);
- addSuccessorWithWeight(SwitchBB, Default);
+ // Both Small and Big will jump to Small.BB, so we sum up the weights.
+ addSuccessorWithWeight(SwitchBB, Small.BB,
+ Small.ExtraWeight + Big.ExtraWeight);
+ addSuccessorWithWeight(SwitchBB, Default,
+ // The default destination is the first successor in IR.
+ BPI ? BPI->getEdgeWeight(SwitchBB->getBasicBlock(), (unsigned)0) : 0);
// Insert the true branch.
SDValue BrCond = DAG.getNode(ISD::BRCOND, DL, MVT::Other,
@@ -1979,14 +1987,13 @@ bool SelectionDAGBuilder::handleSmallSwitchRange(CaseRec& CR,
}
// Order cases by weight so the most likely case will be checked first.
- BranchProbabilityInfo *BPI = FuncInfo.BPI;
+ uint32_t UnhandledWeights = 0;
if (BPI) {
for (CaseItr I = CR.Range.first, IE = CR.Range.second; I != IE; ++I) {
- uint32_t IWeight = BPI->getEdgeWeight(SwitchBB->getBasicBlock(),
- I->BB->getBasicBlock());
+ uint32_t IWeight = I->ExtraWeight;
+ UnhandledWeights += IWeight;
for (CaseItr J = CR.Range.first; J < I; ++J) {
- uint32_t JWeight = BPI->getEdgeWeight(SwitchBB->getBasicBlock(),
- J->BB->getBasicBlock());
+ uint32_t JWeight = J->ExtraWeight;
if (IWeight > JWeight)
std::swap(*I, *J);
}
@@ -2035,10 +2042,12 @@ bool SelectionDAGBuilder::handleSmallSwitchRange(CaseRec& CR,
LHS = I->Low; MHS = SV; RHS = I->High;
}
- uint32_t ExtraWeight = I->ExtraWeight;
+ // The false weight should be sum of all un-handled cases.
+ UnhandledWeights -= I->ExtraWeight;
CaseBlock CB(CC, LHS, RHS, MHS, /* truebb */ I->BB, /* falsebb */ FallThrough,
/* me */ CurBlock,
- /* trueweight */ ExtraWeight / 2, /* falseweight */ ExtraWeight / 2);
+ /* trueweight */ I->ExtraWeight,
+ /* falseweight */ UnhandledWeights);
// If emitting the first comparison, just call visitSwitchCase to emit the
// code into the current block. Otherwise, push the CaseBlock onto the
@@ -2138,13 +2147,28 @@ bool SelectionDAGBuilder::handleJTSwitchCase(CaseRec &CR,
}
}
+ // Calculate weight for each unique destination in CR.
+ DenseMap<MachineBasicBlock*, uint32_t> DestWeights;
+ if (FuncInfo.BPI)
+ for (CaseItr I = CR.Range.first, E = CR.Range.second; I != E; ++I) {
+ DenseMap<MachineBasicBlock*, uint32_t>::iterator Itr =
+ DestWeights.find(I->BB);
+ if (Itr != DestWeights.end())
+ Itr->second += I->ExtraWeight;
+ else
+ DestWeights[I->BB] = I->ExtraWeight;
+ }
+
// Update successor info. Add one edge to each unique successor.
BitVector SuccsHandled(CR.CaseBB->getParent()->getNumBlockIDs());
for (std::vector<MachineBasicBlock*>::iterator I = DestBBs.begin(),
E = DestBBs.end(); I != E; ++I) {
if (!SuccsHandled[(*I)->getNumber()]) {
SuccsHandled[(*I)->getNumber()] = true;
- addSuccessorWithWeight(JumpTableBB, *I);
+ DenseMap<MachineBasicBlock*, uint32_t>::iterator Itr =
+ DestWeights.find(*I);
+ addSuccessorWithWeight(JumpTableBB, *I,
+ Itr != DestWeights.end() ? Itr->second : 0);
}
}
@@ -2375,7 +2399,7 @@ bool SelectionDAGBuilder::handleBitTestsSwitchCase(CaseRec& CR,
if (i == count) {
assert((count < 3) && "Too much destinations to test!");
- CasesBits.push_back(CaseBits(0, Dest, 0));
+ CasesBits.push_back(CaseBits(0, Dest, 0, 0/*Weight*/));
count++;
}
@@ -2384,6 +2408,7 @@ bool SelectionDAGBuilder::handleBitTestsSwitchCase(CaseRec& CR,
uint64_t lo = (lowValue - lowBound).getZExtValue();
uint64_t hi = (highValue - lowBound).getZExtValue();
+ CasesBits[i].ExtraWeight += I->ExtraWeight;
for (uint64_t j = lo; j <= hi; j++) {
CasesBits[i].Mask |= 1ULL << j;
@@ -2411,7 +2436,7 @@ bool SelectionDAGBuilder::handleBitTestsSwitchCase(CaseRec& CR,
CurMF->insert(BBI, CaseBB);
BTC.push_back(BitTestCase(CasesBits[i].Mask,
CaseBB,
- CasesBits[i].BB));
+ CasesBits[i].BB, CasesBits[i].ExtraWeight));
// Put SV in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(SV);
@@ -2439,30 +2464,25 @@ size_t SelectionDAGBuilder::Clusterify(CaseVector& Cases,
Clusterifier TheClusterifier;
+ BranchProbabilityInfo *BPI = FuncInfo.BPI;
// Start with "simple" cases
for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
i != e; ++i) {
const BasicBlock *SuccBB = i.getCaseSuccessor();
MachineBasicBlock *SMBB = FuncInfo.MBBMap[SuccBB];
- TheClusterifier.add(i.getCaseValueEx(), SMBB);
+ TheClusterifier.add(i.getCaseValueEx(), SMBB,
+ BPI ? BPI->getEdgeWeight(SI.getParent(), i.getSuccessorIndex()) : 0);
}
TheClusterifier.optimize();
- BranchProbabilityInfo *BPI = FuncInfo.BPI;
size_t numCmps = 0;
for (Clusterifier::RangeIterator i = TheClusterifier.begin(),
e = TheClusterifier.end(); i != e; ++i, ++numCmps) {
Clusterifier::Cluster &C = *i;
- unsigned W = 0;
- if (BPI) {
- W = BPI->getEdgeWeight(SI.getParent(), C.second->getBasicBlock());
- if (!W)
- W = 16;
- W *= C.first.Weight;
- BPI->setEdgeWeight(SI.getParent(), C.second->getBasicBlock(), W);
- }
+ // Update edge weight for the cluster.
+ unsigned W = C.first.Weight;
// FIXME: Currently work with ConstantInt based numbers.
// Changing it to APInt based is a pretty heavy for this commit.
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index 539514a..3b7615a 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -150,9 +150,11 @@ private:
uint64_t Mask;
MachineBasicBlock* BB;
unsigned Bits;
+ uint32_t ExtraWeight;
- CaseBits(uint64_t mask, MachineBasicBlock* bb, unsigned bits):
- Mask(mask), BB(bb), Bits(bits) { }
+ CaseBits(uint64_t mask, MachineBasicBlock* bb, unsigned bits,
+ uint32_t Weight):
+ Mask(mask), BB(bb), Bits(bits), ExtraWeight(Weight) { }
};
typedef std::vector<Case> CaseVector;
@@ -247,11 +249,13 @@ private:
typedef std::pair<JumpTableHeader, JumpTable> JumpTableBlock;
struct BitTestCase {
- BitTestCase(uint64_t M, MachineBasicBlock* T, MachineBasicBlock* Tr):
- Mask(M), ThisBB(T), TargetBB(Tr) { }
+ BitTestCase(uint64_t M, MachineBasicBlock* T, MachineBasicBlock* Tr,
+ uint32_t Weight):
+ Mask(M), ThisBB(T), TargetBB(Tr), ExtraWeight(Weight) { }
uint64_t Mask;
MachineBasicBlock *ThisBB;
MachineBasicBlock *TargetBB;
+ uint32_t ExtraWeight;
};
typedef SmallVector<BitTestCase, 3> BitTestInfo;
@@ -452,6 +456,7 @@ public:
void visitBitTestHeader(BitTestBlock &B, MachineBasicBlock *SwitchBB);
void visitBitTestCase(BitTestBlock &BB,
MachineBasicBlock* NextMBB,
+ uint32_t BranchWeightToNext,
unsigned Reg,
BitTestCase &B,
MachineBasicBlock *SwitchBB);
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 3e40a45..1f5f825 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1209,7 +1209,12 @@ SelectionDAGISel::FinishBasicBlock() {
CodeGenAndEmitDAG();
}
+ uint32_t UnhandledWeight = 0;
+ for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); j != ej; ++j)
+ UnhandledWeight += SDB->BitTestCases[i].Cases[j].ExtraWeight;
+
for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); j != ej; ++j) {
+ UnhandledWeight -= SDB->BitTestCases[i].Cases[j].ExtraWeight;
// Set the current basic block to the mbb we wish to insert the code into
FuncInfo->MBB = SDB->BitTestCases[i].Cases[j].ThisBB;
FuncInfo->InsertPt = FuncInfo->MBB->end();
@@ -1217,12 +1222,14 @@ SelectionDAGISel::FinishBasicBlock() {
if (j+1 != ej)
SDB->visitBitTestCase(SDB->BitTestCases[i],
SDB->BitTestCases[i].Cases[j+1].ThisBB,
+ UnhandledWeight,
SDB->BitTestCases[i].Reg,
SDB->BitTestCases[i].Cases[j],
FuncInfo->MBB);
else
SDB->visitBitTestCase(SDB->BitTestCases[i],
SDB->BitTestCases[i].Default,
+ UnhandledWeight,
SDB->BitTestCases[i].Reg,
SDB->BitTestCases[i].Cases[j],
FuncInfo->MBB);
generated by cgit v1.1 at 2025-10-31 09:02:56 +0000