Add SinkAddressProjections::newProjections

Author: meg-gupta

include/swift/SILOptimizer/Utils/BasicBlockOptUtils.h

@@ -136,13 +136,19 @@ bool canCloneTerminator(TermInst *termInst);
 class SinkAddressProjections {
   // Projections ordered from last to first in the chain.
   SmallVector<SingleValueInstruction *, 4> oldProjections;
+  // Cloned projections to avoid address phis.
+  SmallVectorImpl<SingleValueInstruction *> *newProjections;
   SmallSetVector<SILValue, 4> inBlockDefs;
 
   // Transient per-projection data for use during cloning.
   SmallVector<Operand *, 4> usesToReplace;
   llvm::SmallDenseMap<SILBasicBlock *, Operand *, 4> firstBlockUse;
 
 public:
+  SinkAddressProjections(
+      SmallVectorImpl<SingleValueInstruction *> *newProjections = nullptr)
+      : newProjections(newProjections) {}
+
   /// Check for an address projection chain ending at \p inst. Return true if
   /// the given instruction is successfully analyzed.
   ///
@@ -163,6 +169,7 @@ class SinkAddressProjections {
   ArrayRef<SILValue> getInBlockDefs() const {
     return inBlockDefs.getArrayRef();
   }
+
   /// Clone the chain of projections at their use sites.
   ///
   /// Return true if anything was done.

lib/SILOptimizer/Utils/BasicBlockOptUtils.cpp

@@ -297,9 +297,12 @@ bool SinkAddressProjections::cloneProjections() {
       auto *useBB = use->getUser()->getParent();
       auto *firstUse = firstBlockUse.lookup(useBB);
       SingleValueInstruction *newProj;
-      if (use == firstUse)
+      if (use == firstUse) {
         newProj = cast<SingleValueInstruction>(oldProj->clone(use->getUser()));
-      else {
+        if (newProjections) {
+          newProjections->push_back(newProj);
+        }
+      } else {
         newProj = cast<SingleValueInstruction>(firstUse->get());
         assert(newProj->getParent() == useBB);
         newProj->moveFront(useBB);