X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FAnalysis.cpp;h=020363524336c4739a063938a50097b3ca8652a2;hb=3d6a30ea3b8272a46b1cd20684a09ea5e56c9548;hp=1600c67a7c62550c48363b688a504e827cd53590;hpb=9d6852cf98dd1e6a939b3469ea49ff7cbc15ad73;p=oota-llvm.git

diff --git a/lib/CodeGen/Analysis.cpp b/lib/CodeGen/Analysis.cpp
index 1600c67a7c6..02036352433 100644
--- a/lib/CodeGen/Analysis.cpp
+++ b/lib/CodeGen/Analysis.cpp
@@ -7,13 +7,14 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file defines several CodeGen-specific LLVM IR analysis utilties.
+// This file defines several CodeGen-specific LLVM IR analysis utilities.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/Analysis.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
@@ -24,6 +25,9 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
+#include "llvm/Transforms/Utils/GlobalStatus.h"
+
 using namespace llvm;
 
 /// ComputeLinearIndex - Given an LLVM IR aggregate type and a sequence
@@ -46,7 +50,7 @@ unsigned llvm::ComputeLinearIndex(Type *Ty,
         EI != EE; ++EI) {
       if (Indices && *Indices == unsigned(EI - EB))
         return ComputeLinearIndex(*EI, Indices+1, IndicesEnd, CurIndex);
-      CurIndex = ComputeLinearIndex(*EI, 0, 0, CurIndex);
+      CurIndex = ComputeLinearIndex(*EI, nullptr, nullptr, CurIndex);
     }
     return CurIndex;
   }
@@ -56,7 +60,7 @@ unsigned llvm::ComputeLinearIndex(Type *Ty,
     for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) {
       if (Indices && *Indices == i)
         return ComputeLinearIndex(EltTy, Indices+1, IndicesEnd, CurIndex);
-      CurIndex = ComputeLinearIndex(EltTy, 0, 0, CurIndex);
+      CurIndex = ComputeLinearIndex(EltTy, nullptr, nullptr, CurIndex);
     }
     return CurIndex;
   }
@@ -228,7 +232,7 @@ static const Value *getNoopInput(const Value *V,
     // through.
     const Instruction *I = dyn_cast<Instruction>(V);
     if (!I || I->getNumOperands() == 0) return V;
-    const Value *NoopInput = 0;
+    const Value *NoopInput = nullptr;
 
     Value *Op = I->getOperand(0);
     if (isa<BitCastInst>(I)) {
@@ -474,8 +478,7 @@ static bool nextRealType(SmallVectorImpl<CompositeType *> &SubTypes,
 /// between it and the return.
 ///
 /// This function only tests target-independent requirements.
-bool llvm::isInTailCallPosition(ImmutableCallSite CS,
-                                const TargetLowering &TLI) {
+bool llvm::isInTailCallPosition(ImmutableCallSite CS, const TargetMachine &TM) {
   const Instruction *I = CS.getInstruction();
   const BasicBlock *ExitBB = I->getParent();
   const TerminatorInst *Term = ExitBB->getTerminator();
@@ -490,16 +493,14 @@ bool llvm::isInTailCallPosition(ImmutableCallSite CS,
   // longjmp on x86), it can end up causing miscompilation that has not
   // been fully understood.
   if (!Ret &&
-      (!TLI.getTargetMachine().Options.GuaranteedTailCallOpt ||
-       !isa<UnreachableInst>(Term)))
+      (!TM.Options.GuaranteedTailCallOpt || !isa<UnreachableInst>(Term)))
     return false;
 
   // If I will have a chain, make sure no other instruction that will have a
   // chain interposes between I and the return.
   if (I->mayHaveSideEffects() || I->mayReadFromMemory() ||
       !isSafeToSpeculativelyExecute(I))
-    for (BasicBlock::const_iterator BBI = prior(prior(ExitBB->end())); ;
-         --BBI) {
+    for (BasicBlock::const_iterator BBI = std::prev(ExitBB->end(), 2);; --BBI) {
       if (&*BBI == I)
         break;
       // Debug info intrinsics do not get in the way of tail call optimization.
@@ -510,7 +511,8 @@ bool llvm::isInTailCallPosition(ImmutableCallSite CS,
         return false;
     }
 
-  return returnTypeIsEligibleForTailCall(ExitBB->getParent(), I, Ret, TLI);
+  return returnTypeIsEligibleForTailCall(
+      ExitBB->getParent(), I, Ret, *TM.getSubtargetImpl()->getTargetLowering());
 }
 
 bool llvm::returnTypeIsEligibleForTailCall(const Function *F,
@@ -607,3 +609,29 @@ bool llvm::returnTypeIsEligibleForTailCall(const Function *F,
 
   return true;
 }
+
+bool llvm::canBeOmittedFromSymbolTable(const GlobalValue *GV) {
+  if (!GV->hasLinkOnceODRLinkage())
+    return false;
+
+  if (GV->hasUnnamedAddr())
+    return true;
+
+  // If it is a non constant variable, it needs to be uniqued across shared
+  // objects.
+  if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) {
+    if (!Var->isConstant())
+      return false;
+  }
+
+  // An alias can point to a variable. We could try to resolve the alias to
+  // decide, but for now just don't hide them.
+  if (isa<GlobalAlias>(GV))
+    return false;
+
+  GlobalStatus GS;
+  if (GlobalStatus::analyzeGlobal(GV, GS))
+    return false;
+
+  return !GS.IsCompared;
+}