Merge pull request #1059 from hylo-lang/emit-literal-cast

Handle lvalue lowering for upcasts on numeric literals

Sources/FrontEnd/TypeChecking/TypeChecker.swift

@@ -3692,7 +3692,7 @@ struct TypeChecker {
       _ = inferredType(of: program[e].left, updating: &obligations)
 
     case .up:
-      // The type of thr LHS must be statically known to subtype of the RHS.
+      // The type of the LHS must be statically known to subtype of the RHS.
       let lhs = inferredType(
         of: program[e].left, withHint: ^freshVariable(), updating: &obligations)
       obligations.insert(SubtypingConstraint(lhs, rhs.shape, origin: cause))

Sources/IR/Analysis/Lifetime.swift

@@ -193,7 +193,7 @@ extension Module {
       case (.closed(let lhs), .liveIn(let rhs)):
         return .liveIn(lastUse: last(lhs, rhs))
       case (.closed(let lhs), .closed(let rhs)):
-        return .liveIn(lastUse: last(lhs, rhs))
+        return .closed(lastUse: last(lhs, rhs))
       }
     }
     return .init(operand: left.operand, coverage: coverage)

Sources/IR/Emitter.swift

@@ -2082,10 +2082,24 @@ struct Emitter {
   /// Inserts the IR for lvalue `e`.
   private mutating func emitLValue(_ e: CastExpr.ID) -> Operand {
     switch ast[e].direction {
+    case .up:
+      return emitLValue(upcast: e)
     case .pointerConversion:
       return emitLValue(pointerConversion: e)
     default:
-      UNIMPLEMENTED()
+      UNIMPLEMENTED("lvalue lowering for cast expressions #1049")
+    }
+  }
+
+  /// Inserts the IR for lvalue `e`.
+  private mutating func emitLValue(upcast e: CastExpr.ID) -> Operand {
+    switch ast[e].left.kind {
+    case FloatLiteralExpr.self:
+      return emitStore(value: ast[e].left)
+    case IntegerLiteralExpr.self:
+      return emitStore(value: ast[e].left)
+    default:
+      UNIMPLEMENTED("lvalue lowering for cast expressions #1049")
     }
   }
 

Tests/HyloTests/TestCases/Lowering/NumericLiteral.hylo

@@ -17,4 +17,7 @@ public fun main() {
 
   let _: Float32 = 1
   let _: Float32 = 1.0
+
+  let _ = 1 as Int8
+  let _ = 1 as Float64
 }