Add C++ global operator {new,new[],delete,delete[]}(unsigned {int,long}) to the

memory builtins as equivalent to malloc/free.

This is different from any attribute we have. For example, you can delete the
allocators when their result is unused, but you can't collapse two calls to the
same function, even if no global/memory state has changed in between. The
noalias return states that the result does not alias any other pointer, but
instcombine optimizes malloc() as though the result is non-null for the purpose
of eliminating unused pointers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127673 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
index 1ab18ca054a2e913f74d288ae67ef637d796e3a7..abec2cb422579c5ab676471bf9f939d800b4a6b3 100644 (file)
--- a/lib/Analysis/MemoryBuiltins.cpp
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -35,7 +35,11 @@ static bool isMallocCall(const CallInst *CI) {
     return false;
 
   Function *Callee = CI->getCalledFunction();
-  if (Callee == 0 || !Callee->isDeclaration() || Callee->getName() != "malloc")
+  if (Callee == 0 || !Callee->isDeclaration())
+    return false;
+  if (Callee->getName() != "malloc" &&
+      Callee->getName() != "_Znwj" && Callee->getName() != "_Znwm" &&
+      Callee->getName() != "_Znaj" && Callee->getName() != "_Znam")
     return false;
 
   // Check malloc prototype.
@@ -189,7 +193,12 @@ const CallInst *llvm::isFreeCall(const Value *I) {
   if (!CI)
     return 0;
   Function *Callee = CI->getCalledFunction();
-  if (Callee == 0 || !Callee->isDeclaration() || Callee->getName() != "free")
+  if (Callee == 0 || !Callee->isDeclaration())
+    return 0;
+
+  if (Callee->getName() != "free" &&
+      Callee->getName() != "_Zdlj" && Callee->getName() != "_Zdlm" &&
+      Callee->getName() != "_Zdaj" && Callee->getName() != "_Zdam")
     return 0;
 
   // Check free prototype.