Draft a constants API

Author: CodaFi

Sources/LLVM/Constant.swift

@@ -0,0 +1,131 @@
+#if !NO_SWIFTPM
+import cllvm
+#endif
+
+public struct Constant: IRValue {
+  internal enum Representation {
+    case unsigned
+    case signed
+    case floating
+  }
+
+  internal let llvm: LLVMValueRef
+  internal let repr: Representation
+
+  /// Retrieves the underlying LLVM constant object.
+  public func asLLVM() -> LLVMValueRef {
+    return llvm
+  }
+
+  internal init(llvm: LLVMValueRef!, representation: Representation) {
+    self.llvm = llvm
+    self.repr = representation
+  }
+
+  public static func +(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    switch lhs.repr {
+    case .signed: fallthrough
+    case .unsigned:
+      return Constant(llvm: LLVMConstAdd(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .floating:
+      return Constant(llvm: LLVMConstFAdd(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    }
+  }
+
+  public static func -(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    switch lhs.repr {
+    case .signed: fallthrough
+    case .unsigned:
+      return Constant(llvm: LLVMConstSub(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .floating:
+      return Constant(llvm: LLVMConstFSub(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    }
+  }
+
+  public static func *(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    switch lhs.repr {
+    case .signed: fallthrough
+    case .unsigned:
+      return Constant(llvm: LLVMConstMul(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .floating:
+      return Constant(llvm: LLVMConstFMul(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    }
+  }
+
+  public static func /(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    switch lhs.repr {
+    case .signed:
+      return Constant(llvm: LLVMConstSDiv(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .unsigned:
+      return Constant(llvm: LLVMConstUDiv(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .floating:
+      return Constant(llvm: LLVMConstFDiv(lhs.llvm, rhs.llvm), representation: lhs.repr)
+    }
+  }
+
+  public static func ==(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    return Constant(llvm: LLVMConstICmp(IntPredicate.eq.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+  }
+
+  public static func <(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    switch lhs.repr {
+    case .signed:
+      return Constant(llvm: LLVMConstICmp(IntPredicate.slt.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .unsigned:
+      return Constant(llvm: LLVMConstICmp(IntPredicate.ult.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .floating:
+      return Constant(llvm: LLVMConstFCmp(RealPredicate.olt.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    }
+  }
+
+  public static func >(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    switch lhs.repr {
+    case .signed:
+      return Constant(llvm: LLVMConstICmp(IntPredicate.sgt.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .unsigned:
+      return Constant(llvm: LLVMConstICmp(IntPredicate.ugt.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .floating:
+      return Constant(llvm: LLVMConstFCmp(RealPredicate.ogt.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    }
+  }
+
+  public static func <=(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    switch lhs.repr {
+    case .signed:
+      return Constant(llvm: LLVMConstICmp(IntPredicate.sle.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .unsigned:
+      return Constant(llvm: LLVMConstICmp(IntPredicate.ule.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .floating:
+      return Constant(llvm: LLVMConstFCmp(RealPredicate.ole.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    }
+  }
+
+  public static func >=(lhs: Constant, rhs: Constant) -> Constant {
+    precondition(lhs.repr == rhs.repr, "Mixed-representation constant operations are disallowed")
+
+    switch lhs.repr {
+    case .signed:
+      return Constant(llvm: LLVMConstICmp(IntPredicate.sge.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .unsigned:
+      return Constant(llvm: LLVMConstICmp(IntPredicate.uge.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    case .floating:
+      return Constant(llvm: LLVMConstFCmp(RealPredicate.oge.llvm, lhs.llvm, rhs.llvm), representation: lhs.repr)
+    }
+  }
+}

Sources/LLVM/FloatType.swift

@@ -19,8 +19,8 @@ public enum FloatType: IRType {
   case ppcFP128
 
   /// Creates a constant floating value of this type from a Swift `Double` value.
-  public func constant(_ value: Double) -> IRValue {
-    return LLVMConstReal(asLLVM(), value)
+  public func constant(_ value: Double) -> Constant {
+    return Constant(llvm: LLVMConstReal(asLLVM(), value), representation: .floating)
   }
 
   /// Retrieves the underlying LLVM type object.