Merge pull request #19714 from eeckstein/fix-cowopt

COWArrayOpts: make the optimization work again for two-dimensional arrays.

Author: eeckstein

include/swift/SIL/InstructionUtils.h

@@ -57,10 +57,6 @@ SILValue stripAddressAccess(SILValue V);
 /// instructions.
 SILValue stripAddressProjections(SILValue V);
 
-/// Return the underlying SILValue after stripping off all address projection
-/// instructions which have a single operand.
-SILValue stripUnaryAddressProjections(SILValue V);
-
 /// Return the underlying SILValue after stripping off all aggregate projection
 /// instructions.
 ///

include/swift/SILOptimizer/Utils/Local.h

@@ -600,13 +600,6 @@ SILType getExactDynamicType(SILValue S, SILModule &M,
 SILType getExactDynamicTypeOfUnderlyingObject(SILValue S, SILModule &M,
                                               ClassHierarchyAnalysis *CHA);
 
-/// Hoist the address projection rooted in \p Op to \p InsertBefore.
-/// Requires the projected value to dominate the insertion point.
-///
-/// Will look through single basic block predecessor arguments.
-void hoistAddressProjections(Operand &Op, SILInstruction *InsertBefore,
-                             DominanceInfo *DomTree);
-
 /// Utility class for cloning init values into the static initializer of a
 /// SILGlobalVariable.
 class StaticInitCloner : public SILCloner<StaticInitCloner> {

lib/SIL/InstructionUtils.cpp

@@ -203,18 +203,6 @@ SILValue swift::stripAddressProjections(SILValue V) {
   }
 }
 
-SILValue swift::stripUnaryAddressProjections(SILValue V) {
-  while (true) {
-    V = stripSinglePredecessorArgs(V);
-    if (!Projection::isAddressProjection(V))
-      return V;
-    auto *Inst = cast<SingleValueInstruction>(V);
-    if (Inst->getNumOperands() > 1)
-      return V;
-    V = Inst->getOperand(0);
-  }
-}
-
 SILValue swift::stripValueProjections(SILValue V) {
   while (true) {
     V = stripSinglePredecessorArgs(V);