Remove dead code. rdar://9221736.

[oota-llvm.git] / lib / CodeGen / Analysis.cpp

diff --git a/lib/CodeGen/Analysis.cpp b/lib/CodeGen/Analysis.cpp
index 57e305ea108f774f1ab48b2432c19f728cfd556b..125e64196f15e11b09c6b49cce56134016b9ba32 100644 (file)
--- a/lib/CodeGen/Analysis.cpp
+++ b/lib/CodeGen/Analysis.cpp
@@ -19,6 +19,7 @@
 #include "llvm/LLVMContext.h"
 #include "llvm/Module.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetOptions.h"
@@ -125,7 +126,7 @@ GlobalVariable *llvm::ExtractTypeInfo(Value *V) {
 /// hasInlineAsmMemConstraint - Return true if the inline asm instruction being
 /// processed uses a memory 'm' constraint.
 bool
-llvm::hasInlineAsmMemConstraint(std::vector<InlineAsm::ConstraintInfo> &CInfos,
+llvm::hasInlineAsmMemConstraint(InlineAsm::ConstraintInfoVector &CInfos,
                                 const TargetLowering &TLI) {
   for (unsigned i = 0, e = CInfos.size(); i != e; ++i) {
     InlineAsm::ConstraintInfo &CI = CInfos[i];
@@ -210,7 +211,6 @@ bool llvm::isInTailCallPosition(ImmutableCallSite CS, Attributes CalleeRetAttr,
   const BasicBlock *ExitBB = I->getParent();
   const TerminatorInst *Term = ExitBB->getTerminator();
   const ReturnInst *Ret = dyn_cast<ReturnInst>(Term);
-  const Function *F = ExitBB->getParent();
 
   // The block must end in a return statement or unreachable.
   //
@@ -249,6 +249,7 @@ bool llvm::isInTailCallPosition(ImmutableCallSite CS, Attributes CalleeRetAttr,
 
   // Conservatively require the attributes of the call to match those of
   // the return. Ignore noalias because it doesn't affect the call sequence.
+  const Function *F = ExitBB->getParent();
   unsigned CallerRetAttr = F->getAttributes().getRetAttributes();
   if ((CalleeRetAttr ^ CallerRetAttr) & ~Attribute::NoAlias)
     return false;
@@ -283,3 +284,20 @@ bool llvm::isInTailCallPosition(ImmutableCallSite CS, Attributes CalleeRetAttr,
   return true;
 }
 
+bool llvm::isInTailCallPosition(SelectionDAG &DAG, SDNode *Node,
+                                const TargetLowering &TLI) {
+  const Function *F = DAG.getMachineFunction().getFunction();
+
+  // Conservatively require the attributes of the call to match those of
+  // the return. Ignore noalias because it doesn't affect the call sequence.
+  unsigned CallerRetAttr = F->getAttributes().getRetAttributes();
+  if (CallerRetAttr & ~Attribute::NoAlias)
+    return false;
+
+  // It's not safe to eliminate the sign / zero extension of the return value.
+  if ((CallerRetAttr & Attribute::ZExt) || (CallerRetAttr & Attribute::SExt))
+    return false;
+
+  // Check if the only use is a function return node.
+  return TLI.isUsedByReturnOnly(Node);
+}