Add support for invoke to the MemoryBuiltin analysid.

Update comments accordingly.

Make instcombine remove useless invokes to C++'s 'new' allocation function (test attached).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158937 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 29 insertions, 17 deletions

diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
index 86d9135..26d466e 100644
--- a/lib/Analysis/MemoryBuiltins.cpp
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -65,11 +65,17 @@ static const AllocFnsTy AllocationFnData[] = {
 static Function *getCalledFunction(const Value *V, bool LookThroughBitCast) {
   if (LookThroughBitCast)
     V = V->stripPointerCasts();
-  const CallInst *CI = dyn_cast<CallInst>(V);
-  if (!CI)
+
+  Value *I = const_cast<Value*>(V);
+  CallSite CS;
+  if (CallInst *CI = dyn_cast<CallInst>(I))
+    CS = CallSite(CI);
+  else if (InvokeInst *II = dyn_cast<InvokeInst>(I))
+    CS = CallSite(II);
+  else
     return 0;
 
-  Function *Callee = CI->getCalledFunction();
+  Function *Callee = CS.getCalledFunction();
   if (!Callee || !Callee->isDeclaration())
     return 0;
   return Callee;
@@ -122,39 +128,40 @@ static bool hasNoAliasAttr(const Value *V, bool LookThroughBitCast) {
 }
 
 
-/// \brief Tests if a value is a call to a library function that allocates or
-/// reallocates memory (either malloc, calloc, realloc, or strdup like).
+/// \brief Tests if a value is a call or invoke to a library function that
+/// allocates or reallocates memory (either malloc, calloc, realloc, or strdup
+/// like).
 bool llvm::isAllocationFn(const Value *V, bool LookThroughBitCast) {
   return getAllocationData(V, AnyAlloc, LookThroughBitCast);
 }
 
-/// \brief Tests if a value is a call to a function that returns a NoAlias
-/// pointer (including malloc/calloc/strdup-like functions).
+/// \brief Tests if a value is a call or invoke to a function that returns a
+/// NoAlias pointer (including malloc/calloc/strdup-like functions).
 bool llvm::isNoAliasFn(const Value *V, bool LookThroughBitCast) {
   return isAllocLikeFn(V, LookThroughBitCast) ||
          hasNoAliasAttr(V, LookThroughBitCast);
 }
 
-/// \brief Tests if a value is a call to a library function that allocates
-/// uninitialized memory (such as malloc).
+/// \brief Tests if a value is a call or invoke to a library function that
+/// allocates uninitialized memory (such as malloc).
 bool llvm::isMallocLikeFn(const Value *V, bool LookThroughBitCast) {
   return getAllocationData(V, MallocLike, LookThroughBitCast);
 }
 
-/// \brief Tests if a value is a call to a library function that allocates
-/// zero-filled memory (such as calloc).
+/// \brief Tests if a value is a call or invoke to a library function that
+/// allocates zero-filled memory (such as calloc).
 bool llvm::isCallocLikeFn(const Value *V, bool LookThroughBitCast) {
   return getAllocationData(V, CallocLike, LookThroughBitCast);
 }
 
-/// \brief Tests if a value is a call to a library function that allocates
-/// memory (either malloc, calloc, or strdup like).
+/// \brief Tests if a value is a call or invoke to a library function that
+/// allocates memory (either malloc, calloc, or strdup like).
 bool llvm::isAllocLikeFn(const Value *V, bool LookThroughBitCast) {
   return getAllocationData(V, AllocLike, LookThroughBitCast);
 }
 
-/// \brief Tests if a value is a call to a library function that reallocates
-/// memory (such as realloc).
+/// \brief Tests if a value is a call or invoke to a library function that
+/// reallocates memory (such as realloc).
 bool llvm::isReallocLikeFn(const Value *V, bool LookThroughBitCast) {
   return getAllocationData(V, ReallocLike, LookThroughBitCast);
 }
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index ed38829..b638cc2 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -172,8 +172,6 @@ Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
 Instruction *InstCombiner::visitCallInst(CallInst &CI) {
   if (isFreeCall(&CI))
     return visitFree(CI);
-  if (isAllocLikeFn(&CI))
-    return visitMalloc(CI);
 
   // If the caller function is nounwind, mark the call as nounwind, even if the
   // callee isn't.
@@ -881,6 +879,9 @@ static IntrinsicInst *FindInitTrampoline(Value *Callee) {
 // visitCallSite - Improvements for call and invoke instructions.
 //
 Instruction *InstCombiner::visitCallSite(CallSite CS) {
+  if (isAllocLikeFn(CS.getInstruction()))
+    return visitMalloc(*CS.getInstruction());
+
   bool Changed = false;
 
   // If the callee is a pointer to a function, attempt to move any casts to the
diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index 2653fc3..269ea15 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1167,6 +1167,10 @@ Instruction *InstCombiner::visitMalloc(Instruction &MI) {
       }
       EraseInstFromFunction(*I);
     }
+
+    if (InvokeInst *II = dyn_cast<InvokeInst>(&MI)) {
+      BranchInst::Create(II->getNormalDest(), II->getParent());
+    }
     return EraseInstFromFunction(MI);
   }
   return 0;