Add Value.definingInstructionOrTerminator

Author: atrick

SwiftCompilerSources/Sources/Optimizer/DataStructures/InstructionRange.swift

@@ -64,10 +64,8 @@ struct InstructionRange : CustomStringConvertible, NoReflectionChildren {
   }
 
   static func beginningInstruction(for value: Value) -> Instruction {
-    if let def = value.definingInstruction {
+    if let def = value.definingInstructionOrTerminator {
       return def
-    } else if let result = TerminatorResult(value) {
-      return result.terminator
     }
     assert(Phi(value) != nil || value is FunctionArgument)
     return value.parentBlock.instructions.first!

SwiftCompilerSources/Sources/SIL/ForwardingInstruction.swift

@@ -66,12 +66,9 @@ extension Value {
   // If this value is produced by a ForwardingInstruction, return that instruction. This is convenient for following the forwarded value chain.
   // Unlike definingInstruction, a value's forwardingInstruction is not necessarily a valid insertion point. 
   public var forwardingInstruction: ForwardingInstruction? {
-    if let inst = definingInstruction {
+    if let inst = definingInstructionOrTerminator {
       return inst as? ForwardingInstruction
     }
-    if let termResult = TerminatorResult(self) {
-      return termResult.terminator as? ForwardingInstruction
-    }
     return nil
   }
 }

SwiftCompilerSources/Sources/SIL/Value.swift

@@ -138,6 +138,15 @@ extension Value {
     }
   }
 
+  public var definingInstructionOrTerminator: Instruction? {
+    if let def = definingInstruction {
+      return def
+    } else if let result = TerminatorResult(self) {
+      return result.terminator
+    }
+    return nil
+  }
+
   public var nextInstruction: Instruction {
     if self is Argument {
       return parentBlock.instructions.first!