#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Metadata.h"
-#include "llvm/Support/CFG.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
+#define DEBUG_TYPE "branch-prob"
+
INITIALIZE_PASS_BEGIN(BranchProbabilityInfo, "branch-prob",
"Branch Probability Analysis", false, true)
INITIALIZE_PASS_DEPENDENCY(LoopInfo)
InEdges.push_back(I.getSuccessorIndex());
}
+ if (BackEdges.empty() && ExitingEdges.empty())
+ return false;
+
if (uint32_t numBackEdges = BackEdges.size()) {
uint32_t backWeight = LBH_TAKEN_WEIGHT / numBackEdges;
if (backWeight < NORMAL_WEIGHT)
}
bool BranchProbabilityInfo::runOnFunction(Function &F) {
+ DEBUG(dbgs() << "---- Branch Probability Info : " << F.getName()
+ << " ----\n\n");
LastF = &F; // Store the last function we ran on for printing.
LI = &getAnalysis<LoopInfo>();
assert(PostDominatedByUnreachable.empty());
BasicBlock *BranchProbabilityInfo::getHotSucc(BasicBlock *BB) const {
uint32_t Sum = 0;
uint32_t MaxWeight = 0;
- BasicBlock *MaxSucc = 0;
+ BasicBlock *MaxSucc = nullptr;
for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
BasicBlock *Succ = *I;
if (BranchProbability(MaxWeight, Sum) > BranchProbability(4, 5))
return MaxSucc;
- return 0;
+ return nullptr;
}
/// Get the raw edge weight for the edge. If can't find it, return
return DEFAULT_WEIGHT;
}
+uint32_t BranchProbabilityInfo::getEdgeWeight(const BasicBlock *Src,
+ succ_const_iterator Dst) const {
+ return getEdgeWeight(Src, Dst.getSuccessorIndex());
+}
+
/// Get the raw edge weight calculated for the block pair. This returns the sum
/// of all raw edge weights from Src to Dst.
uint32_t BranchProbabilityInfo::