Merge pull request #67919 from nate-chandler/rdar113762355

[Mem2Reg] Don't canonicalize erased values.

Author: nate-chandler

lib/SILOptimizer/Transforms/SILMem2Reg.cpp

@@ -2195,7 +2195,7 @@ void MemoryToRegisters::canonicalizeValueLifetimes(
       /*pruneDebug=*/true, /*maximizeLifetime=*/!f.shouldOptimize(), &f,
       accessBlockAnalysis, domInfo, calleeAnalysis, deleter);
   for (auto value : owned) {
-    if (isa<SILUndef>(value))
+    if (isa<SILUndef>(value) || value->isMarkedAsDeleted())
       continue;
     auto root = CanonicalizeOSSALifetime::getCanonicalCopiedDef(value);
     if (auto *copy = dyn_cast<CopyValueInst>(root)) {
@@ -2209,7 +2209,7 @@ void MemoryToRegisters::canonicalizeValueLifetimes(
   }
   CanonicalizeBorrowScope borrowCanonicalizer(&f, deleter);
   for (auto value : guaranteed) {
-    if (isa<SILUndef>(value))
+    if (isa<SILUndef>(value) || value->isMarkedAsDeleted())
       continue;
     auto borrowee = CanonicalizeBorrowScope::getCanonicalBorrowedDef(value);
     if (!borrowee)

test/SILOptimizer/mem2reg_ossa.sil

@@ -742,3 +742,22 @@ sil [ossa] @dont_canonicalize_undef : $@convention(thin) () -> () {
   %retval = tuple ()
   return %retval : $()
 }
+
+// CHECK-LABEL: sil [ossa] @dont_canonicalize_erased_copy : {{.*}} {
+// CHECK:       bb0(%0 :
+// CHECK:         destroy_value %0
+// CHECK-LABEL: } // end sil function 'dont_canonicalize_erased_copy'
+sil [ossa] @dont_canonicalize_erased_copy : $@convention(thin) (@owned C) -> () {
+entry(%instance : @owned $C):
+  %stack = alloc_stack $C
+  %copy = copy_value %instance : $C
+  store %copy to [init] %stack : $*C
+  %loaded_copy = load [take] %stack : $*C
+  destroy_value %loaded_copy : $C
+  store %instance to [init] %stack : $*C
+  %loaded_instance = load [take] %stack : $*C
+  destroy_value %loaded_instance : $C
+  dealloc_stack %stack : $*C
+  %retval = tuple ()
+  return %retval : $()
+}