Teach MemoryBuiltins and InstructionSimplify that operator new never returns NULL.
This is safe per C++11 18.6.1.1p3: [operator new returns] a non-null pointer to
suitably aligned storage (3.7.4), or else throw a bad_alloc exception. This
requirement is binding on a replacement version of this function.
Brings us a tiny bit closer to eliminating more vector push_backs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191310 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index c815375..e7a512c 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -15,6 +15,7 @@
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/GlobalAlias.h"
@@ -2064,7 +2065,7 @@
/// isKnownNonNull - Return true if we know that the specified value is never
/// null.
-bool llvm::isKnownNonNull(const Value *V) {
+bool llvm::isKnownNonNull(const Value *V, const TargetLibraryInfo *TLI) {
// Alloca never returns null, malloc might.
if (isa<AllocaInst>(V)) return true;
@@ -2075,5 +2076,10 @@
// Global values are not null unless extern weak.
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
return !GV->hasExternalWeakLinkage();
+
+ // operator new never returns null.
+ if (isOperatorNewLikeFn(V, TLI, /*LookThroughBitCast=*/true))
+ return true;
+
return false;
}