[llvm-commits] [llvm] r136529 - in /llvm/trunk/lib/CodeGen/SelectionDAG: SelectionDAGBuilder.cpp SelectionDAGBuilder.h
Jakub Staszak
jstaszak at apple.com
Fri Jul 29 15:25:21 PDT 2011
Author: kuba
Date: Fri Jul 29 17:25:21 2011
New Revision: 136529
URL: http://llvm.org/viewvc/llvm-project?rev=136529&view=rev
Log:
Do not lose branch weights when lowering SwitchInst.
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=136529&r1=136528&r2=136529&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Fri Jul 29 17:25:21 2011
@@ -1282,10 +1282,12 @@
return BPI->getEdgeWeight(SrcBB, DstBB);
}
-void SelectionDAGBuilder::addSuccessorWithWeight(MachineBasicBlock *Src,
- MachineBasicBlock *Dst) {
- uint32_t weight = getEdgeWeight(Src, Dst);
- Src->addSuccessor(Dst, weight);
+void SelectionDAGBuilder::
+addSuccessorWithWeight(MachineBasicBlock *Src, MachineBasicBlock *Dst,
+ uint32_t Weight /* = 0 */) {
+ if (!Weight)
+ Weight = getEdgeWeight(Src, Dst);
+ Src->addSuccessor(Dst, Weight);
}
@@ -1558,8 +1560,8 @@
}
// Update successor info
- addSuccessorWithWeight(SwitchBB, CB.TrueBB);
- addSuccessorWithWeight(SwitchBB, CB.FalseBB);
+ addSuccessorWithWeight(SwitchBB, CB.TrueBB, CB.TrueWeight);
+ addSuccessorWithWeight(SwitchBB, CB.FalseBB, CB.FalseWeight);
// Set NextBlock to be the MBB immediately after the current one, if any.
// This is used to avoid emitting unnecessary branches to the next block.
@@ -1910,8 +1912,8 @@
ISD::SETEQ);
// Update successor info.
- SwitchBB->addSuccessor(Small.BB);
- SwitchBB->addSuccessor(Default);
+ addSuccessorWithWeight(SwitchBB, Small.BB);
+ addSuccessorWithWeight(SwitchBB, Default);
// Insert the true branch.
SDValue BrCond = DAG.getNode(ISD::BRCOND, DL, MVT::Other,
@@ -1967,7 +1969,11 @@
CC = ISD::SETLE;
LHS = I->Low; MHS = SV; RHS = I->High;
}
- CaseBlock CB(CC, LHS, RHS, MHS, I->BB, FallThrough, CurBlock);
+
+ uint32_t ExtraWeight = I->ExtraWeight;
+ CaseBlock CB(CC, LHS, RHS, MHS, /* truebb */ I->BB, /* falsebb */ FallThrough,
+ /* me */ CurBlock,
+ /* trueweight */ ExtraWeight / 2, /* falseweight */ ExtraWeight / 2);
// If emitting the first comparison, just call visitSwitchCase to emit the
// code into the current block. Otherwise, push the CaseBlock onto the
@@ -2362,12 +2368,17 @@
const SwitchInst& SI) {
size_t numCmps = 0;
+ BranchProbabilityInfo *BPI = FuncInfo.BPI;
// Start with "simple" cases
for (size_t i = 1; i < SI.getNumSuccessors(); ++i) {
- MachineBasicBlock *SMBB = FuncInfo.MBBMap[SI.getSuccessor(i)];
+ BasicBlock *SuccBB = SI.getSuccessor(i);
+ MachineBasicBlock *SMBB = FuncInfo.MBBMap[SuccBB];
+
+ uint32_t ExtraWeight = BPI ? BPI->getEdgeWeight(SI.getParent(), SuccBB) : 0;
+
Cases.push_back(Case(SI.getSuccessorValue(i),
SI.getSuccessorValue(i),
- SMBB));
+ SMBB, ExtraWeight));
}
std::sort(Cases.begin(), Cases.end(), CaseCmp());
@@ -2387,6 +2398,16 @@
if ((nextValue - currentValue == 1) && (currentBB == nextBB)) {
I->High = J->High;
J = Cases.erase(J);
+
+ if (BranchProbabilityInfo *BPI = FuncInfo.BPI) {
+ uint32_t CurWeight = currentBB->getBasicBlock() ?
+ BPI->getEdgeWeight(SI.getParent(), currentBB->getBasicBlock()) : 16;
+ uint32_t NextWeight = nextBB->getBasicBlock() ?
+ BPI->getEdgeWeight(SI.getParent(), nextBB->getBasicBlock()) : 16;
+
+ BPI->setEdgeWeight(SI.getParent(), currentBB->getBasicBlock(),
+ CurWeight + NextWeight);
+ }
} else {
I = J++;
}
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h?rev=136529&r1=136528&r2=136529&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h Fri Jul 29 17:25:21 2011
@@ -132,10 +132,13 @@
Constant* Low;
Constant* High;
MachineBasicBlock* BB;
+ uint32_t ExtraWeight;
+
+ Case() : Low(0), High(0), BB(0), ExtraWeight(0) { }
+ Case(Constant* low, Constant* high, MachineBasicBlock* bb,
+ uint32_t extraweight) : Low(low), High(high), BB(bb),
+ ExtraWeight(extraweight) { }
- Case() : Low(0), High(0), BB(0) { }
- Case(Constant* low, Constant* high, MachineBasicBlock* bb) :
- Low(low), High(high), BB(bb) { }
APInt size() const {
const APInt &rHigh = cast<ConstantInt>(High)->getValue();
const APInt &rLow = cast<ConstantInt>(Low)->getValue();
@@ -203,20 +206,30 @@
CaseBlock(ISD::CondCode cc, const Value *cmplhs, const Value *cmprhs,
const Value *cmpmiddle,
MachineBasicBlock *truebb, MachineBasicBlock *falsebb,
- MachineBasicBlock *me)
+ MachineBasicBlock *me,
+ uint32_t trueweight = 0, uint32_t falseweight = 0)
: CC(cc), CmpLHS(cmplhs), CmpMHS(cmpmiddle), CmpRHS(cmprhs),
- TrueBB(truebb), FalseBB(falsebb), ThisBB(me) {}
+ TrueBB(truebb), FalseBB(falsebb), ThisBB(me),
+ TrueWeight(trueweight), FalseWeight(falseweight) { }
+
// CC - the condition code to use for the case block's setcc node
ISD::CondCode CC;
+
// CmpLHS/CmpRHS/CmpMHS - The LHS/MHS/RHS of the comparison to emit.
// Emit by default LHS op RHS. MHS is used for range comparisons:
// If MHS is not null: (LHS <= MHS) and (MHS <= RHS).
const Value *CmpLHS, *CmpMHS, *CmpRHS;
+
// TrueBB/FalseBB - the block to branch to if the setcc is true/false.
MachineBasicBlock *TrueBB, *FalseBB;
+
// ThisBB - the block into which to emit the code for the setcc and branches
MachineBasicBlock *ThisBB;
+
+ // TrueWeight/FalseWeight - branch weights.
+ uint32_t TrueWeight, FalseWeight;
};
+
struct JumpTable {
JumpTable(unsigned R, unsigned J, MachineBasicBlock *M,
MachineBasicBlock *D): Reg(R), JTI(J), MBB(M), Default(D) {}
@@ -436,7 +449,8 @@
MachineBasicBlock *SwitchBB);
uint32_t getEdgeWeight(MachineBasicBlock *Src, MachineBasicBlock *Dst);
- void addSuccessorWithWeight(MachineBasicBlock *Src, MachineBasicBlock *Dst);
+ void addSuccessorWithWeight(MachineBasicBlock *Src, MachineBasicBlock *Dst,
+ uint32_t Weight = 0);
public:
void visitSwitchCase(CaseBlock &CB,
MachineBasicBlock *SwitchBB);
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