LTO: -internalize sets visibility to default

[oota-llvm.git] / lib / Analysis / IPA / InlineCost.cpp

diff --git a/lib/Analysis/IPA/InlineCost.cpp b/lib/Analysis/IPA/InlineCost.cpp
index 683637f5b7f737eb24c0539544b8b0474e9593df..358f61fd5231480323fc82662e519b98efcad554 100644 (file)
--- a/lib/Analysis/IPA/InlineCost.cpp
+++ b/lib/Analysis/IPA/InlineCost.cpp
@@ -11,7 +11,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "inline-cost"
 #include "llvm/Analysis/InlineCost.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SetVector.h"
@@ -34,6 +33,8 @@
 
 using namespace llvm;
 
+#define DEBUG_TYPE "inline-cost"
+
 STATISTIC(NumCallsAnalyzed, "Number of call sites analyzed");
 
 namespace {
@@ -97,9 +98,6 @@ class CallAnalyzer : public InstVisitor<CallAnalyzer, bool> {
   void disableSROA(Value *V);
   void accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
                           int InstructionCost);
-  bool handleSROACandidate(bool IsSROAValid,
-                           DenseMap<Value *, int>::iterator CostIt,
-                           int InstructionCost);
   bool isGEPOffsetConstant(GetElementPtrInst &GEP);
   bool accumulateGEPOffset(GEPOperator &GEP, APInt &Offset);
   bool simplifyCallSite(Function *F, CallSite CS);
@@ -225,21 +223,6 @@ void CallAnalyzer::accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
   SROACostSavings += InstructionCost;
 }
 
-/// \brief Helper for the common pattern of handling a SROA candidate.
-/// Either accumulates the cost savings if the SROA remains valid, or disables
-/// SROA for the candidate.
-bool CallAnalyzer::handleSROACandidate(bool IsSROAValid,
-                                       DenseMap<Value *, int>::iterator CostIt,
-                                       int InstructionCost) {
-  if (IsSROAValid) {
-    accumulateSROACost(CostIt, InstructionCost);
-    return true;
-  }
-
-  disableSROA(CostIt);
-  return false;
-}
-
 /// \brief Check whether a GEP's indices are all constant.
 ///
 /// Respects any simplified values known during the analysis of this callsite.
@@ -825,9 +808,29 @@ bool CallAnalyzer::visitBranchInst(BranchInst &BI) {
 bool CallAnalyzer::visitSwitchInst(SwitchInst &SI) {
   // We model unconditional switches as free, see the comments on handling
   // branches.
-  return isa<ConstantInt>(SI.getCondition()) ||
-         dyn_cast_or_null<ConstantInt>(
-             SimplifiedValues.lookup(SI.getCondition()));
+  if (isa<ConstantInt>(SI.getCondition()))
+    return true;
+  if (Value *V = SimplifiedValues.lookup(SI.getCondition()))
+    if (isa<ConstantInt>(V))
+      return true;
+
+  // Otherwise, we need to accumulate a cost proportional to the number of
+  // distinct successor blocks. This fan-out in the CFG cannot be represented
+  // for free even if we can represent the core switch as a jumptable that
+  // takes a single instruction.
+  //
+  // NB: We convert large switches which are just used to initialize large phi
+  // nodes to lookup tables instead in simplify-cfg, so this shouldn't prevent
+  // inlining those. It will prevent inlining in cases where the optimization
+  // does not (yet) fire.
+  SmallPtrSet<BasicBlock *, 8> SuccessorBlocks;
+  SuccessorBlocks.insert(SI.getDefaultDest());
+  for (auto I = SI.case_begin(), E = SI.case_end(); I != E; ++I)
+    SuccessorBlocks.insert(I.getCaseSuccessor());
+  // Add cost corresponding to the number of distinct destinations. The first
+  // we model as free because of fallthrough.
+  Cost += (SuccessorBlocks.size() - 1) * InlineConstants::InstrCost;
+  return false;
 }
 
 bool CallAnalyzer::visitIndirectBrInst(IndirectBrInst &IBI) {
@@ -943,7 +946,7 @@ bool CallAnalyzer::analyzeBlock(BasicBlock *BB) {
 /// no constant offsets applied.
 ConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) {
   if (!DL || !V->getType()->isPointerTy())
-    return 0;
+    return nullptr;
 
   unsigned IntPtrWidth = DL->getPointerSizeInBits();
   APInt Offset = APInt::getNullValue(IntPtrWidth);
@@ -955,7 +958,7 @@ ConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) {
   do {
     if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
       if (!GEP->isInBounds() || !accumulateGEPOffset(*GEP, Offset))
-        return 0;
+        return nullptr;
       V = GEP->getPointerOperand();
     } else if (Operator::getOpcode(V) == Instruction::BitCast) {
       V = cast<Operator>(V)->getOperand(0);
@@ -1300,14 +1303,8 @@ bool InlineCostAnalysis::isInlineViable(Function &F) {
     F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
                                    Attribute::ReturnsTwice);
   for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
-    // Disallow inlining of functions which contain an indirect branch,
-    // unless the always_inline attribute is set.
-    // The attribute serves as a assertion that no local address
-    // like a block label can escpape the function.
-    // Revisit enabling inlining for functions with indirect branches
-    // when a more sophisticated espape/points-to analysis becomes available.
-    if (isa<IndirectBrInst>(BI->getTerminator()) &&
-        !F.hasFnAttribute(Attribute::AlwaysInline))
+    // Disallow inlining of functions which contain an indirect branch.
+    if (isa<IndirectBrInst>(BI->getTerminator()))
       return false;
 
     for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;