simplify CallSite helper class to not consult the Instruction's

opcode on each delegation.
Instead the information is cached on construction and the cached flag used thereafter.
Introduced two predicates: isCall and isInvoke.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62055 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 71 insertions, 80 deletions

diff --git a/include/llvm/Support/CallSite.h b/include/llvm/Support/CallSite.h
index 025f9da681..544c7d7761 100644
--- a/include/llvm/Support/CallSite.h
+++ b/include/llvm/Support/CallSite.h
@@ -14,15 +14,19 @@
 // passed by value, not by reference; it should not be "new"ed or "delete"d. It
 // is efficiently copyable, assignable and constructable, with cost equivalent
 // to copying a pointer (notice that it has only a single data member).
+// The internal representation carries a flag which indicates which of the two
+// variants is enclosed. This allows for cheaper checks when various accessors
+// of CallSite are employed.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_SUPPORT_CALLSITE_H
 #define LLVM_SUPPORT_CALLSITE_H
 
-#include "llvm/Instruction.h"
-#include "llvm/BasicBlock.h"
 #include "llvm/Attributes.h"
+#include "llvm/ADT/PointerIntPair.h"
+#include "llvm/BasicBlock.h"
+#include "llvm/Instruction.h"
 
 namespace llvm {
 
@@ -30,17 +34,19 @@ class CallInst;
 class InvokeInst;
 
 class CallSite {
-  Instruction *I;
+  PointerIntPair<Instruction*, 1, bool> I;
 public:
-  CallSite() : I(0) {}
-  CallSite(CallInst *CI) : I(reinterpret_cast<Instruction*>(CI)) {}
-  CallSite(InvokeInst *II) : I(reinterpret_cast<Instruction*>(II)) {}
+  CallSite() : I(0, false) {}
+  CallSite(CallInst *CI) : I(reinterpret_cast<Instruction*>(CI), true) {}
+  CallSite(InvokeInst *II) : I(reinterpret_cast<Instruction*>(II), false) {}
   CallSite(Instruction *C);
   CallSite(const CallSite &CS) : I(CS.I) {}
   CallSite &operator=(const CallSite &CS) { I = CS.I; return *this; }
 
-  bool operator==(const CallSite &CS) const { return I == CS.I; }
-  bool operator!=(const CallSite &CS) const { return I != CS.I; }
+  bool operator==(const CallSite &CS) const { return getInstruction()
+                                                == CS.getInstruction(); }
+  bool operator!=(const CallSite &CS) const { return getInstruction()
+                                                != CS.getInstruction(); }
   
   /// CallSite::get - This static method is sort of like a constructor.  It will
   /// create an appropriate call site for a Call or Invoke instruction, but it
@@ -91,21 +97,31 @@ public:
 
   /// getType - Return the type of the instruction that generated this call site
   ///
-  const Type *getType() const { return I->getType(); }
+  const Type *getType() const { return getInstruction()->getType(); }
+
+  /// isCall - true if a CallInst is enclosed.
+  /// Note that !isCall() does not mean it is an InvokeInst enclosed,
+  /// it also could signify a NULL Instruction pointer.
+  bool isCall() const { return I.getInt(); }
+
+  /// isInvoke - true if a InvokeInst is enclosed.
+  ///
+  bool isInvoke() const { return getInstruction() && !I.getInt(); }
 
   /// getInstruction - Return the instruction this call site corresponds to
   ///
-  Instruction *getInstruction() const { return I; }
+  Instruction *getInstruction() const { return I.getPointer(); }
 
   /// getCaller - Return the caller function for this call site
   ///
-  Function *getCaller() const { return I->getParent()->getParent(); }
+  Function *getCaller() const { return getInstruction()
+                                  ->getParent()->getParent(); }
 
   /// getCalledValue - Return the pointer to function that is being called...
   ///
   Value *getCalledValue() const {
-    assert(I && "Not a call or invoke instruction!");
-    return I->getOperand(0);
+    assert(getInstruction() && "Not a call or invoke instruction!");
+    return getInstruction()->getOperand(0);
   }
 
   /// getCalledFunction - Return the function being called if this is a direct
@@ -118,8 +134,8 @@ public:
   /// setCalledFunction - Set the callee to the specified value...
   ///
   void setCalledFunction(Value *V) {
-    assert(I && "Not a call or invoke instruction!");
-    I->setOperand(0, V);
+    assert(getInstruction() && "Not a call or invoke instruction!");
+    getInstruction()->setOperand(0, V);
   }
 
   Value *getArgument(unsigned ArgNo) const {
@@ -128,9 +144,9 @@ public:
   }
 
   void setArgument(unsigned ArgNo, Value* newVal) {
-    assert(I && "Not a call or invoke instruction!");
+    assert(getInstruction() && "Not a call or invoke instruction!");
     assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
-    I->setOperand(getArgumentOffset() + ArgNo, newVal);
+    getInstruction()->setOperand(getArgumentOffset() + ArgNo, newVal);
   }
 
   /// Given an operand number, returns the argument that corresponds to it.
@@ -153,11 +169,12 @@ public:
   /// arg_begin/arg_end - Return iterators corresponding to the actual argument
   /// list for a call site.
   arg_iterator arg_begin() const {
-    assert(I && "Not a call or invoke instruction!");
-    return I->op_begin() + getArgumentOffset(); // Skip non-arguments
+    assert(getInstruction() && "Not a call or invoke instruction!");
+		// Skip non-arguments
+    return getInstruction()->op_begin() + getArgumentOffset();
   }
 
-  arg_iterator arg_end() const { return I->op_end(); }
+  arg_iterator arg_end() const { return getInstruction()->op_end(); }
   bool arg_empty() const { return arg_end() == arg_begin(); }
   unsigned arg_size() const { return unsigned(arg_end() - arg_begin()); }
 
@@ -168,7 +185,7 @@ public:
 private:
   /// Returns the operand number of the first argument
   unsigned getArgumentOffset() const {
-    if (I->getOpcode() == Instruction::Call)
+    if (isCall())
       return 1; // Skip Function
     else
       return 3; // Skip Function, BB, BB
diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index e2ba9b49b0..1b5cfb1501 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -25,94 +25,65 @@ using namespace llvm;
 //                            CallSite Class
 //===----------------------------------------------------------------------===//
 
+#define CALLSITE_DELEGATE_GETTER(METHOD) \
+  Instruction *II(getInstruction());     \
+  return isCall()                        \
+    ? cast<CallInst>(II)->METHOD         \
+    : cast<InvokeInst>(II)->METHOD
+
+#define CALLSITE_DELEGATE_SETTER(METHOD) \
+  Instruction *II(getInstruction());     \
+  if (isCall())                          \
+    cast<CallInst>(II)->METHOD;          \
+  else                                   \
+    cast<InvokeInst>(II)->METHOD
+
 CallSite::CallSite(Instruction *C) {
   assert((isa<CallInst>(C) || isa<InvokeInst>(C)) && "Not a call!");
-  I = C;
+  I.setPointer(C);
+  I.setInt(isa<CallInst>(C));
 }
 unsigned CallSite::getCallingConv() const {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    return CI->getCallingConv();
-  else
-    return cast<InvokeInst>(I)->getCallingConv();
+  CALLSITE_DELEGATE_GETTER(getCallingConv());
 }
 void CallSite::setCallingConv(unsigned CC) {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    CI->setCallingConv(CC);
-  else
-    cast<InvokeInst>(I)->setCallingConv(CC);
+  CALLSITE_DELEGATE_SETTER(setCallingConv(CC));
 }
 const AttrListPtr &CallSite::getAttributes() const {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    return CI->getAttributes();
-  else
-    return cast<InvokeInst>(I)->getAttributes();
+  CALLSITE_DELEGATE_GETTER(getAttributes());
 }
 void CallSite::setAttributes(const AttrListPtr &PAL) {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    CI->setAttributes(PAL);
-  else
-    cast<InvokeInst>(I)->setAttributes(PAL);
+  CALLSITE_DELEGATE_SETTER(setAttributes(PAL));
 }
 bool CallSite::paramHasAttr(uint16_t i, Attributes attr) const {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    return CI->paramHasAttr(i, attr);
-  else
-    return cast<InvokeInst>(I)->paramHasAttr(i, attr);
+  CALLSITE_DELEGATE_GETTER(paramHasAttr(i, attr));
 }
 uint16_t CallSite::getParamAlignment(uint16_t i) const {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    return CI->getParamAlignment(i);
-  else
-    return cast<InvokeInst>(I)->getParamAlignment(i);
+  CALLSITE_DELEGATE_GETTER(getParamAlignment(i));
 }
-
 bool CallSite::doesNotAccessMemory() const {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    return CI->doesNotAccessMemory();
-  else
-    return cast<InvokeInst>(I)->doesNotAccessMemory();
+  CALLSITE_DELEGATE_GETTER(doesNotAccessMemory());
 }
 void CallSite::setDoesNotAccessMemory(bool doesNotAccessMemory) {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    CI->setDoesNotAccessMemory(doesNotAccessMemory);
-  else
-    cast<InvokeInst>(I)->setDoesNotAccessMemory(doesNotAccessMemory);
+  CALLSITE_DELEGATE_SETTER(setDoesNotAccessMemory(doesNotAccessMemory));
 }
 bool CallSite::onlyReadsMemory() const {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    return CI->onlyReadsMemory();
-  else
-    return cast<InvokeInst>(I)->onlyReadsMemory();
+  CALLSITE_DELEGATE_GETTER(onlyReadsMemory());
 }
 void CallSite::setOnlyReadsMemory(bool onlyReadsMemory) {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    CI->setOnlyReadsMemory(onlyReadsMemory);
-  else
-    cast<InvokeInst>(I)->setOnlyReadsMemory(onlyReadsMemory);
+  CALLSITE_DELEGATE_SETTER(setOnlyReadsMemory(onlyReadsMemory));
 }
 bool CallSite::doesNotReturn() const {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    return CI->doesNotReturn();
-  else
-    return cast<InvokeInst>(I)->doesNotReturn();
+ CALLSITE_DELEGATE_GETTER(doesNotReturn());
 }
 void CallSite::setDoesNotReturn(bool doesNotReturn) {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    CI->setDoesNotReturn(doesNotReturn);
-  else
-    cast<InvokeInst>(I)->setDoesNotReturn(doesNotReturn);
+  CALLSITE_DELEGATE_SETTER(setDoesNotReturn(doesNotReturn));
 }
 bool CallSite::doesNotThrow() const {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    return CI->doesNotThrow();
-  else
-    return cast<InvokeInst>(I)->doesNotThrow();
+  CALLSITE_DELEGATE_GETTER(doesNotThrow());
 }
 void CallSite::setDoesNotThrow(bool doesNotThrow) {
-  if (CallInst *CI = dyn_cast<CallInst>(I))
-    CI->setDoesNotThrow(doesNotThrow);
-  else
-    cast<InvokeInst>(I)->setDoesNotThrow(doesNotThrow);
+  CALLSITE_DELEGATE_SETTER(setDoesNotThrow(doesNotThrow));
 }
 
 bool CallSite::hasArgument(const Value *Arg) const {
@@ -122,6 +93,9 @@ bool CallSite::hasArgument(const Value *Arg) const {
   return false;
 }
 
+#undef CALLSITE_DELEGATE_GETTER
+#undef CALLSITE_DELEGATE_SETTER
+
 //===----------------------------------------------------------------------===//
 //                            TerminatorInst Class
 //===----------------------------------------------------------------------===//
@@ -1442,7 +1416,7 @@ InsertValueInst::InsertValueInst(Value *Agg,
 //===----------------------------------------------------------------------===//
 
 void ExtractValueInst::init(const unsigned *Idx, unsigned NumIdx,
-			    const std::string &Name) {
+                            const std::string &Name) {
   assert(NumOperands == 1 && "NumOperands not initialized?");
 
   Indices.insert(Indices.end(), Idx, Idx + NumIdx);