libswift: add AliasAnalysis

Author: eeckstein

include/swift/SILOptimizer/OptimizerBridging.h

@@ -29,15 +29,26 @@ typedef struct {
   BridgedPassContext passContext;
 } BridgedInstructionPassCtxt;
 
-typedef void (*BridgedFunctionPassRunFn)(BridgedFunctionPassCtxt);
-typedef void (*BridgedInstructionPassRunFn)(BridgedInstructionPassCtxt);
+typedef struct {
+  const void * _Nonnull aliasAnalysis;
+} BridgedAliasAnalysis;
+
+typedef void (* _Nonnull BridgedFunctionPassRunFn)(BridgedFunctionPassCtxt);
+typedef void (* _Nonnull BridgedInstructionPassRunFn)(BridgedInstructionPassCtxt);
 
 void SILPassManager_registerFunctionPass(BridgedStringRef name,
                                          BridgedFunctionPassRunFn runFn);
 
 void SILCombine_registerInstructionPass(BridgedStringRef name,
                                         BridgedInstructionPassRunFn runFn);
 
+BridgedAliasAnalysis PassContext_getAliasAnalysis(BridgedPassContext context,
+                                                  BridgedFunction function);
+
+BridgedMemoryBehavior AliasAnalysis_getMemBehavior(BridgedAliasAnalysis aa,
+                                                   BridgedInstruction inst,
+                                                   BridgedValue addr);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif

include/swift/SILOptimizer/PassManager/PassManager.h

@@ -59,6 +59,8 @@ class LibswiftPassInvocation {
   LibswiftPassInvocation(SILPassManager *passManager, SILCombiner *silCombiner) :
     passManager(passManager), silCombiner(silCombiner) {}
 
+  SILPassManager *getPassManager() const { return passManager; }
+
   FixedSizeSlab *allocSlab(FixedSizeSlab *afterSlab);
 
   FixedSizeSlab *freeSlab(FixedSizeSlab *slab);

lib/SILOptimizer/Analysis/AliasAnalysis.cpp

@@ -12,6 +12,7 @@
 
 #define DEBUG_TYPE "sil-aa"
 #include "swift/SILOptimizer/Analysis/AliasAnalysis.h"
+#include "swift/SIL/SILBridgingUtils.h"
 #include "swift/SIL/InstructionUtils.h"
 #include "swift/SIL/Projection.h"
 #include "swift/SIL/SILArgument.h"
@@ -27,6 +28,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include "swift/SILOptimizer/OptimizerBridging.h"
 
 using namespace swift;
 
@@ -808,3 +810,19 @@ class AliasAnalysisContainer : public FunctionAnalysisBase<AliasAnalysis> {
 SILAnalysis *swift::createAliasAnalysis(SILModule *M) {
   return new AliasAnalysisContainer();
 }
+
+//===----------------------------------------------------------------------===//
+//                            Swift Bridging
+//===----------------------------------------------------------------------===//
+
+inline AliasAnalysis *castToAliasAnalysis(BridgedAliasAnalysis aa) {
+  return  const_cast<AliasAnalysis *>(
+    static_cast<const AliasAnalysis *>(aa.aliasAnalysis));
+}
+
+BridgedMemoryBehavior AliasAnalysis_getMemBehavior(BridgedAliasAnalysis aa,
+                                                   BridgedInstruction inst,
+                                                   BridgedValue addr) {
+  return (BridgedMemoryBehavior)castToAliasAnalysis(aa)->
+    computeMemoryBehavior(castToInst(inst), castToSILValue(addr));
+}

lib/SILOptimizer/PassManager/PassManager.cpp

@@ -19,6 +19,7 @@
 #include "swift/SIL/SILBridgingUtils.h"
 #include "swift/SIL/SILFunction.h"
 #include "swift/SIL/SILModule.h"
+#include "swift/SILOptimizer/Analysis/AliasAnalysis.h"
 #include "swift/SILOptimizer/Analysis/BasicCalleeAnalysis.h"
 #include "swift/SILOptimizer/Analysis/FunctionOrder.h"
 #include "swift/SILOptimizer/OptimizerBridging.h"
@@ -1165,3 +1166,9 @@ void PassContext_eraseInstruction(BridgedPassContext passContext,
   castToPassInvocation(passContext)->eraseInstruction(castToInst(inst));
 }
 
+BridgedAliasAnalysis PassContext_getAliasAnalysis(BridgedPassContext context,
+                                                  BridgedFunction function) {
+  SILPassManager *pm = castToPassInvocation(context)->getPassManager();
+  return {pm->getAnalysis<AliasAnalysis>(castToFunction(function))};
+}
+

libswift/Sources/Optimizer/Analysis/AliasAnalysis.swift

@@ -0,0 +1,46 @@
+//===--- AliasAnalysis.swift - the alias analysis -------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import OptimizerBridging
+import SIL
+
+struct AliasAnalysis {
+  let bridged: BridgedAliasAnalysis
+  
+  func mayRead(_ inst: Instruction, fromAddress: Value) -> Bool {
+    switch AliasAnalysis_getMemBehavior(bridged, inst.bridged, fromAddress.bridged) {
+      case MayReadBehavior, MayReadWriteBehavior, MayHaveSideEffectsBehavior:
+        return true
+      default:
+        return false
+    }
+  }
+
+  func mayWrite(_ inst: Instruction, toAddress: Value) -> Bool {
+    switch AliasAnalysis_getMemBehavior(bridged, inst.bridged, toAddress.bridged) {
+      case MayWriteBehavior, MayReadWriteBehavior, MayHaveSideEffectsBehavior:
+        return true
+      default:
+        return false
+    }
+  }
+
+  func mayReadOrWrite(_ inst: Instruction, address: Value) -> Bool {
+    switch AliasAnalysis_getMemBehavior(bridged, inst.bridged, address.bridged) {
+      case MayReadBehavior, MayWriteBehavior, MayReadWriteBehavior,
+           MayHaveSideEffectsBehavior:
+        return true
+      default:
+        return false
+    }
+  }
+}

libswift/Sources/Optimizer/Analysis/CMakeLists.txt

@@ -0,0 +1,10 @@
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See http://swift.org/LICENSE.txt for license information
+# See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+
+libswift_sources(Optimizer
+  AliasAnalysis.swift)

libswift/Sources/Optimizer/CMakeLists.txt

@@ -9,6 +9,7 @@
 add_libswift_module(Optimizer
     DEPENDS SIL)
 
+add_subdirectory(Analysis)
 add_subdirectory(InstructionPasses)
 add_subdirectory(PassManager)
 add_subdirectory(FunctionPasses)

libswift/Sources/Optimizer/PassManager/PassUtils.swift

@@ -30,6 +30,11 @@ struct FunctionPassContext {
   private func notifyChanges(_ kind: ChangeNotificationKind) {
     PassContext_notifyChanges(passContext, kind)
   }
+
+  var aliasAnalysis: AliasAnalysis {
+    let bridgedAA = PassContext_getAliasAnalysis(passContext, function.bridged)
+    return AliasAnalysis(bridged: bridgedAA)
+  }
 }
 
 struct FunctionPass {