libswift: add a few utilities

* add the IntegerLiteralInst + the Builder function to create it
* add Value.nonDebugUses
* add a general utility Sequence.isEmpty
* add PassContext.replaceAllUses
* add a function to erase all `debug_value` uses in PassContext.erase

Author: eeckstein

include/swift/SIL/SILBridging.h

@@ -237,6 +237,8 @@ BridgedInstruction SILBuilder_createBuiltinBinaryFunction(
           BridgedType operandType, BridgedType resultType, BridgedValueArray arguments);
 BridgedInstruction SILBuilder_createCondFail(BridgedInstruction insertionPoint,
           BridgedLocation loc, BridgedValue condition, BridgedStringRef messge);
+BridgedInstruction SILBuilder_createIntegerLiteral(BridgedInstruction insertionPoint,
+          BridgedLocation loc, BridgedType type, SwiftInt value);
 
 SWIFT_END_NULLABILITY_ANNOTATIONS
 

include/swift/SIL/SILNodes.def

@@ -469,7 +469,7 @@ ABSTRACT_VALUE_AND_INST(SingleValueInstruction, ValueBase, SILInstruction)
                       LiteralInst, None, DoesNotRelease)
     BRIDGED_SINGLE_VALUE_INST(GlobalValueInst, global_value,
                       LiteralInst, None, DoesNotRelease)
-    SINGLE_VALUE_INST(IntegerLiteralInst, integer_literal,
+    BRIDGED_SINGLE_VALUE_INST(IntegerLiteralInst, integer_literal,
                       LiteralInst, None, DoesNotRelease)
     SINGLE_VALUE_INST(FloatLiteralInst, float_literal,
                       LiteralInst, None, DoesNotRelease)

lib/SIL/Utils/SILBridging.cpp

@@ -513,3 +513,11 @@ BridgedInstruction SILBuilder_createCondFail(BridgedInstruction insertionPoint,
   return {builder.createCondFail(getRegularLocation(loc),
     castToSILValue(condition), getStringRef(messge))};
 }
+
+BridgedInstruction SILBuilder_createIntegerLiteral(BridgedInstruction insertionPoint,
+          BridgedLocation loc, BridgedType type, SwiftInt value) {
+  SILBuilder builder(castToInst(insertionPoint), getSILDebugScope(loc));
+  return {builder.createIntegerLiteral(getRegularLocation(loc),
+                                       getSILType(type), value)};
+}
+

libswift/Sources/Optimizer/CMakeLists.txt

@@ -13,3 +13,4 @@ add_subdirectory(Analysis)
 add_subdirectory(InstructionPasses)
 add_subdirectory(PassManager)
 add_subdirectory(FunctionPasses)
+add_subdirectory(Utilities)

libswift/Sources/Optimizer/PassManager/PassUtils.swift

@@ -36,7 +36,23 @@ struct PassContext {
     return CalleeAnalysis(bridged: bridgeCA)
   }
 
-  func erase(instruction: Instruction) {
+  enum EraseMode {
+    case onlyInstruction, includingDebugUses
+  }
+
+  func erase(instruction: Instruction, _ mode: EraseMode = .onlyInstruction) {
+    switch mode {
+      case .onlyInstruction:
+        break
+      case .includingDebugUses:
+        for result in instruction.results {
+          for use in result.uses {
+            assert(use.instruction is DebugValueInst)
+            PassContext_eraseInstruction(passContext, use.instruction.bridged)
+          }
+        }
+    }
+  
     if instruction is FullApplySite {
       PassContext_notifyChanges(passContext, callsChanged)
     }
@@ -47,7 +63,13 @@ struct PassContext {
 
     PassContext_eraseInstruction(passContext, instruction.bridged)
   }
-  
+
+  func replaceAllUses(of value: Value, with replacement: Value) {
+    for use in value.uses {
+      setOperand(of: use.instruction, at: use.index, to: replacement)
+    }
+  }
+
   func setOperand(of instruction: Instruction, at index : Int, to value: Value) {
     if instruction is FullApplySite && index == ApplyOperands.calleeOperandIndex {
       PassContext_notifyChanges(passContext, callsChanged)

libswift/Sources/Optimizer/Utilities/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
+  OptUtils.swift)

libswift/Sources/Optimizer/Utilities/OptUtils.swift

@@ -0,0 +1,19 @@
+//===--- OptUtils.swift - Utilities for optimzations ----------------------===//
+//
+// 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 SIL
+
+extension Value {
+  var nonDebugUses: LazyFilterSequence<UseList> {
+    uses.lazy.filter { !($0.instruction is DebugValueInst) }
+  }
+}

libswift/Sources/SIL/Builder.swift

@@ -60,4 +60,11 @@ public struct Builder {
       return cf.getAs(CondFailInst.self)
     }
   }
+  
+  public func createIntegerLiteral(_ value: Int, type: Type) -> IntegerLiteralInst {
+    notifyInstructionsChanged()
+    let literal = SILBuilder_createIntegerLiteral(
+      bridgedInsPoint, location.bridgedLocation, type.bridged, value)
+    return literal.getAs(IntegerLiteralInst.self)
+  }
 }

libswift/Sources/SIL/Instruction.swift

@@ -326,6 +326,8 @@ final public class GlobalAddrInst : GlobalAccessInst {}
 
 final public class GlobalValueInst : GlobalAccessInst {}
 
+final public class IntegerLiteralInst : SingleValueInstruction {}
+
 final public class TupleInst : SingleValueInstruction {
 }
 

libswift/Sources/SIL/Registration.swift

@@ -77,6 +77,7 @@ public func registerSILClasses() {
   register(ExistentialMetatypeInst.self)
   register(GlobalAddrInst.self)
   register(GlobalValueInst.self)
+  register(IntegerLiteralInst.self)
   register(TupleInst.self)
   register(TupleExtractInst.self)
   register(TupleElementAddrInst.self)