Merge pull request swiftlang#23309 from shajrawi/licm_static

[exclusivity] teach LICM how to handle static markers

Author: Joe Shajrawi

lib/SILOptimizer/LoopTransforms/LICM.cpp

@@ -554,10 +554,6 @@ static bool analyzeBeginAccess(BeginAccessInst *BI,
                                WriteSet &MayWrites,
                                AccessedStorageAnalysis *ASA,
                                DominanceInfo *DT) {
-  if (BI->getEnforcement() != SILAccessEnforcement::Dynamic) {
-    return false;
-  }
-
   const AccessedStorage &storage =
       findAccessedStorageNonNested(BI->getSource());
   if (!storage) {
@@ -654,9 +650,7 @@ void LoopTreeOptimization::analyzeCurrentLoop(
       case SILInstructionKind::BeginAccessInst: {
         auto *BI = dyn_cast<BeginAccessInst>(&Inst);
         assert(BI && "Expected a Begin Access");
-        if (BI->getEnforcement() == SILAccessEnforcement::Dynamic) {
-          BeginAccesses.push_back(BI);
-        }
+        BeginAccesses.push_back(BI);
         checkSideEffects(Inst, MayWrites);
         break;
       }

test/SILOptimizer/licm_exclusivity.sil

@@ -16,6 +16,10 @@ var globalX: X
 
 sil_global hidden @globalX : $X
 
+var globalY: X
+
+sil_global hidden @globalY : $X
+
 
 sil hidden_external [global_init] @globalAddressor : $@convention(thin) () -> Builtin.RawPointer
 
@@ -142,3 +146,107 @@ bb2:
   %10 = tuple ()
   return %10 : $()
 }
+
+// public func hoist_access_static() {
+// Tests Hoisting of begin/end access when there's a static access
+//
+// CHECK-LABEL: sil @hoist_access_static : $@convention(thin) () -> () {
+// CHECK: [[GLOBAL:%.*]] = global_addr @globalX : $*X
+// CHECK: [[BEGIN:%.*]] = begin_access [read] [static] [[GLOBAL]] : $*X
+// CHECK-NEXT: br bb1
+// CHECK: apply
+// CHECK: load
+// CHECK: cond_br
+// CHECK: bb2
+// CHECK: end_access [[BEGIN]]
+// CHECK-LABEL: } // end sil function 'hoist_access_static'
+sil @hoist_access_static : $@convention(thin) () -> () {
+bb0:
+  %0 = global_addr @globalX: $*X
+  %u0 = function_ref @globalAddressor : $@convention(thin) () -> Builtin.RawPointer
+  br bb1
+  
+bb1:
+  %u3 = begin_access [read] [static] %0 : $*X
+  %u1 = apply %u0() : $@convention(thin) () -> Builtin.RawPointer
+  %u4 = load %u3 : $*X
+  end_access %u3 : $*X
+  cond_br undef, bb1, bb2
+
+bb2:
+  %10 = tuple ()
+  return %10 : $()
+}
+
+// public func hoist_access_static_and_dynamic() {
+// Tests Hoisting of begin/end access when there's a static and distinct dynamic access
+//
+// CHECK-LABEL: sil @hoist_access_static_and_dynamic : $@convention(thin) () -> () {
+// CHECK: [[GLOBAL:%.*]] = global_addr @globalX : $*X
+// CHECK: [[GLOBALY:%.*]] = global_addr @globalY : $*X
+// CHECK: [[BEGIN:%.*]] = begin_access [read] [static] [[GLOBAL]] : $*X
+// CHECK: [[BEGINY:%.*]] = begin_access [read] [dynamic] [[GLOBALY]] : $*X
+// CHECK-NEXT: br bb1
+// CHECK: load
+// CHECK: load
+// CHECK: cond_br
+// CHECK: bb2
+// CHECK: end_access [[BEGINY]]
+// CHECK: end_access [[BEGIN]]
+// CHECK-LABEL: } // end sil function 'hoist_access_static_and_dynamic'
+sil @hoist_access_static_and_dynamic : $@convention(thin) () -> () {
+bb0:
+  %0 = global_addr @globalX: $*X
+  %1 = global_addr @globalY: $*X
+  br bb1
+  
+bb1:
+  %x3 = begin_access [read] [static] %0 : $*X
+  %x4 = load %x3 : $*X
+  end_access %x3 : $*X
+  %y3 = begin_access [read] [dynamic] %1 : $*X
+  %y4 = load %y3 : $*X
+  end_access %y3 : $*X
+  cond_br undef, bb1, bb2
+
+bb2:
+  %10 = tuple ()
+  return %10 : $()
+}
+
+// public func dont_hoist_access_static_and_dynamic() {
+// Tests bailing out when there's a static and non-distinct dynamic access
+//
+// CHECK-LABEL: sil @dont_hoist_access_static_and_dynamic : $@convention(thin) () -> () {
+// CHECK: [[GLOBAL:%.*]] = global_addr @globalX : $*X
+// CHECK: [[GLOBALX:%.*]] = global_addr @globalX : $*X
+// CHECK-NEXT: br bb1
+// CHECK: [[BEGIN:%.*]] = begin_access [read] [static] [[GLOBAL]] : $*X
+// CHECK-NEXT: load
+// CHECK: end_access [[BEGIN]]
+// CHECK: [[BEGINX:%.*]] = begin_access [read] [dynamic] [[GLOBALX]] : $*X
+// CHECK-NEXT: load
+// CHECK: end_access [[BEGINX]]
+// CHECK: cond_br
+// CHECK: bb2
+// CHECK: return %{{.*}} : $()
+// CHECK-LABEL: } // end sil function 'dont_hoist_access_static_and_dynamic'
+sil @dont_hoist_access_static_and_dynamic : $@convention(thin) () -> () {
+bb0:
+  %0 = global_addr @globalX: $*X
+  %1 = global_addr @globalX: $*X
+  br bb1
+  
+bb1:
+  %x3 = begin_access [read] [static] %0 : $*X
+  %x4 = load %x3 : $*X
+  end_access %x3 : $*X
+  %y3 = begin_access [read] [dynamic] %1 : $*X
+  %y4 = load %y3 : $*X
+  end_access %y3 : $*X
+  cond_br undef, bb1, bb2
+
+bb2:
+  %10 = tuple ()
+  return %10 : $()
+}