//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "branch-prob"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Metadata.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
using namespace llvm;
+#define DEBUG_TYPE "branch-prob"
+
INITIALIZE_PASS_BEGIN(BranchProbabilityInfo, "branch-prob",
"Branch Probability Analysis", false, true)
-INITIALIZE_PASS_DEPENDENCY(LoopInfo)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_END(BranchProbabilityInfo, "branch-prob",
"Branch Probability Analysis", false, true)
SmallVector<uint32_t, 2> Weights;
Weights.reserve(TI->getNumSuccessors());
for (unsigned i = 1, e = WeightsNode->getNumOperands(); i != e; ++i) {
- ConstantInt *Weight = dyn_cast<ConstantInt>(WeightsNode->getOperand(i));
+ ConstantInt *Weight =
+ mdconst::dyn_extract<ConstantInt>(WeightsNode->getOperand(i));
if (!Weight)
return false;
Weights.push_back(
if (!CV)
return false;
+ // If the LHS is the result of AND'ing a value with a single bit bitmask,
+ // we don't have information about probabilities.
+ if (Instruction *LHS = dyn_cast<Instruction>(CI->getOperand(0)))
+ if (LHS->getOpcode() == Instruction::And)
+ if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(LHS->getOperand(1)))
+ if (AndRHS->getUniqueInteger().isPowerOf2())
+ return false;
+
bool isProb;
if (CV->isZero()) {
switch (CI->getPredicate()) {
}
void BranchProbabilityInfo::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<LoopInfo>();
+ AU.addRequired<LoopInfoWrapperPass>();
AU.setPreservesAll();
}
DEBUG(dbgs() << "---- Branch Probability Info : " << F.getName()
<< " ----\n\n");
LastF = &F; // Store the last function we ran on for printing.
- LI = &getAnalysis<LoopInfo>();
+ LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
assert(PostDominatedByUnreachable.empty());
assert(PostDominatedByColdCall.empty());
// Walk the basic blocks in post-order so that we can build up state about
// the successors of a block iteratively.
- for (po_iterator<BasicBlock *> I = po_begin(&F.getEntryBlock()),
- E = po_end(&F.getEntryBlock());
- I != E; ++I) {
- DEBUG(dbgs() << "Computing probabilities for " << I->getName() << "\n");
- if (calcUnreachableHeuristics(*I))
+ for (auto BB : post_order(&F.getEntryBlock())) {
+ DEBUG(dbgs() << "Computing probabilities for " << BB->getName() << "\n");
+ if (calcUnreachableHeuristics(BB))
continue;
- if (calcMetadataWeights(*I))
+ if (calcMetadataWeights(BB))
continue;
- if (calcColdCallHeuristics(*I))
+ if (calcColdCallHeuristics(BB))
continue;
- if (calcLoopBranchHeuristics(*I))
+ if (calcLoopBranchHeuristics(BB))
continue;
- if (calcPointerHeuristics(*I))
+ if (calcPointerHeuristics(BB))
continue;
- if (calcZeroHeuristics(*I))
+ if (calcZeroHeuristics(BB))
continue;
- if (calcFloatingPointHeuristics(*I))
+ if (calcFloatingPointHeuristics(BB))
continue;
- calcInvokeHeuristics(*I);
+ calcInvokeHeuristics(BB);
}
PostDominatedByUnreachable.clear();
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