[GlobalOpt] support ConstantExpr use of global address for OptimizeGlobalAddressOfMalloc

I'm working on extending the OptimizeGlobalAddressOfMalloc to handle some more general cases. This is to add support of the ConstantExpr use of the global variables. The function allUsesOfLoadedValueWillTrapIfNull is now iterative with the added CE use of GV. Also, the recursive function valueIsOnlyUsedLocallyOrStoredToOneGlobal is changed to iterative using a worklist with the GEP case added.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D106589

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Utils/GlobalStatus.cpp b/llvm/lib/Transforms/Utils/GlobalStatus.cpp
index f782396..4c3e164 100644
--- a/llvm/lib/Transforms/Utils/GlobalStatus.cpp
+++ b/llvm/lib/Transforms/Utils/GlobalStatus.cpp
@@ -105,8 +105,10 @@ static bool analyzeGlobalAux(const Value *V, GlobalStatus &GS,
         // value, not an aggregate), keep more specific information about
         // stores.
         if (GS.StoredType != GlobalStatus::Stored) {
-          if (const GlobalVariable *GV =
-                  dyn_cast<GlobalVariable>(SI->getOperand(1))) {
+          const Value *Ptr = SI->getPointerOperand();
+          if (isa<ConstantExpr>(Ptr))
+            Ptr = Ptr->stripPointerCasts();
+          if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr)) {
             Value *StoredVal = SI->getOperand(0);
 
             if (Constant *C = dyn_cast<Constant>(StoredVal)) {