From dce4a407a24b04eebc6a376f8e62b41aaa7b071f Mon Sep 17 00:00:00 2001
From: Stephen Hines <srhines@google.com>
Date: Thu, 29 May 2014 02:49:00 -0700
Subject: Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
---
 lib/Analysis/IPA/InlineCost.cpp | 64 ++++++++++++++++++++++++-----------------
 1 file changed, 38 insertions(+), 26 deletions(-)

(limited to 'lib/Analysis/IPA/InlineCost.cpp')

diff --git a/lib/Analysis/IPA/InlineCost.cpp b/lib/Analysis/IPA/InlineCost.cpp
index 8dafc1c..66f3f8e 100644
--- 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.
@@ -287,8 +270,17 @@ bool CallAnalyzer::accumulateGEPOffset(GEPOperator &GEP, APInt &Offset) {
 }
 
 bool CallAnalyzer::visitAlloca(AllocaInst &I) {
-  // FIXME: Check whether inlining will turn a dynamic alloca into a static
+  // Check whether inlining will turn a dynamic alloca into a static
   // alloca, and handle that case.
+  if (I.isArrayAllocation()) {
+    if (Constant *Size = SimplifiedValues.lookup(I.getArraySize())) {
+      ConstantInt *AllocSize = dyn_cast<ConstantInt>(Size);
+      assert(AllocSize && "Allocation size not a constant int?");
+      Type *Ty = I.getAllocatedType();
+      AllocatedSize += Ty->getPrimitiveSizeInBits() * AllocSize->getZExtValue();
+      return Base::visitAlloca(I);
+    }
+  }
 
   // Accumulate the allocated size.
   if (I.isStaticAlloca()) {
@@ -816,9 +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) {
@@ -934,7 +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);
@@ -946,7 +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);
@@ -1247,7 +1259,7 @@ InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee,
 
   // Calls to functions with always-inline attributes should be inlined
   // whenever possible.
-  if (Callee->hasFnAttribute(Attribute::AlwaysInline)) {
+  if (CS.hasFnAttr(Attribute::AlwaysInline)) {
     if (isInlineViable(*Callee))
       return llvm::InlineCost::getAlways();
     return llvm::InlineCost::getNever();
-- 
cgit v1.1