stdlib: remove bitwise operations on Bool

Bitwise operations on Bool are redundant with other logic operations
that stdlib already provides.  The only reason to have them was to avoid
branching in the short-circuiting && and ||.

rdar://19340952

Surprisingly, replacing & and | in the standard library with && and ||
brought performance improvements and no significant performance
regressions:

RecursiveOwnedParameter 1.14
SelectionSort 1.19

Swift SVN r24674

stdlib/core/Bool.swift

@@ -64,27 +64,6 @@ extension Bool : Printable {
 public // COMPILER_INTRINSIC
 func _getBool(v: Builtin.Int1) -> Bool { return Bool(v) }
 
-//===----------------------------------------------------------------------===//
-// Standard Operators
-//===----------------------------------------------------------------------===//
-
-// Unary bitwise complement.
-@transparent
-public prefix func ~(a: Bool) -> Bool {
-  return a ^ true
-}
-
-// Unary logical complement.
-@transparent
-public prefix func !(a: Bool) -> Bool {
-  return ~a
-}
-
-@transparent
-public func ==(lhs: Bool, rhs: Bool) -> Bool {
-  return Bool(Builtin.cmp_eq_Int1(lhs.value, rhs.value))
-}
-
 @transparent
 extension Bool : Equatable, Hashable {
   /// The hash value.
@@ -99,36 +78,64 @@ extension Bool : Equatable, Hashable {
   }
 }
 
+//===----------------------------------------------------------------------===//
+// Operators
+//===----------------------------------------------------------------------===//
+
+// Unary logical complement.
+@transparent
+public prefix func !(a: Bool) -> Bool {
+  return Bool(Builtin.xor_Int1(a.value, true.value))
+}
+
+@transparent
+public func ==(lhs: Bool, rhs: Bool) -> Bool {
+  return Bool(Builtin.cmp_eq_Int1(lhs.value, rhs.value))
+}
+
+//===----------------------------------------------------------------------===//
+// Unavailable Operators
+//===----------------------------------------------------------------------===//
+
+// Unary bitwise complement.
+@availability(*, unavailable, message="use the '!' operator instead")
+public prefix func ~(a: Bool) -> Bool {
+  _preconditionFailure("unavailable function can not be called")
+}
+
 // Bitwise 'and'.
-@transparent public func & (lhs: Bool, rhs: Bool) -> Bool {
+@availability(*, unavailable, message="use the '&&' operator instead")
-  return Bool(Builtin.and_Int1(lhs.value, rhs.value))
+public func & (lhs: Bool, rhs: Bool) -> Bool {
+  _preconditionFailure("unavailable function can not be called")
 }
 
 // Bitwise 'xor'.
-@transparent public func ^ (lhs: Bool, rhs: Bool) -> Bool {
+@availability(*, unavailable, message="use the '!=' operator instead")
-  return Bool(Builtin.xor_Int1(lhs.value, rhs.value))
+public func ^ (lhs: Bool, rhs: Bool) -> Bool {
+  _preconditionFailure("unavailable function can not be called")
 }
 
 // Bitwise 'or'.
-@transparent public func | (lhs: Bool, rhs: Bool) -> Bool {
+@availability(*, unavailable, message="use the '||' operator instead")
-  return Bool(Builtin.or_Int1(lhs.value, rhs.value))
+public func | (lhs: Bool, rhs: Bool) -> Bool {
+  _preconditionFailure("unavailable function can not be called")
 }
 
 // Compound assignment (with bitwise and)
-@transparent
+@availability(*, unavailable, message="use the '&&' operator instead")
 public func &= (inout lhs: Bool, rhs: Bool) {
-  lhs = lhs & rhs
+  _preconditionFailure("unavailable function can not be called")
 }
 
 // Compound assignment (with bitwise or)
-@transparent
+@availability(*, unavailable, message="use the '||' operator instead")
 public func |= (inout lhs: Bool, rhs: Bool) {
-  lhs = lhs | rhs
+  _preconditionFailure("unavailable function can not be called")
 }
 
 // Compound assignment (with bitwise xor)
-@transparent
+@availability(*, unavailable, message="use the '!=' operator instead")
 public func ^= (inout lhs: Bool, rhs: Bool) {
-  lhs = lhs ^ rhs
+  _preconditionFailure("unavailable function can not be called")
 }
 

stdlib/core/ContiguousArrayBuffer.swift

@@ -339,7 +339,7 @@ public struct _ContiguousArrayBuffer<T> : _ArrayBufferType {
     /// Note that this is better than folding hasStorage in to
     /// the return from this function, as this implementation generates
     /// no shortcircuiting blocks.
-    return (index >= 0) & (index < __bufferPointer.value.count)
+    return (index >= 0) && (index < __bufferPointer.value.count)
   }
 
   /// How many elements the buffer can store without reallocation

stdlib/core/FixedPoint.swift.gyb

@@ -534,7 +534,7 @@ public func ${op} (lhs: ${Self}, rhs: ${Self}) -> ${Self} {
 public func ${op}(lhs: ${Self}, rhs: ${Self}) -> ${Self} {
   Builtin.condfail((rhs == 0).value)
 % if signed:
-  Builtin.condfail(((lhs == ${Self}.min) & (rhs == -1)).value)
+  Builtin.condfail(((lhs == ${Self}.min) && (rhs == -1)).value)
 % end
   // FIXME: currently doesn't detect overflow -- blocked by:
   // <rdar://15735295> Need [su]{div,rem}_with_overflow IR

stdlib/core/SwiftNativeNSArray.swift

@@ -25,14 +25,14 @@ import SwiftShims
 /// ≤ index ≤ count`
 @transparent
 internal func _isValidArrayIndex(index: Int, count: Int) -> Bool {
-  return (index >= 0) & (index <= count)
+  return (index >= 0) && (index <= count)
 }
 
 /// Return true iff the given `index` is valid for subscripting, i.e.
 /// `0 ≤ index < count`
 @transparent
 internal func _isValidArraySubscript(index: Int, count: Int) -> Bool {
-  return (index >= 0) & (index < count)
+  return (index >= 0) && (index < count)
 }
 
 /// An `NSArray` with Swift-native reference counting and contiguous

stdlib/core/UnitTestArrayBuffer.swift

@@ -185,7 +185,7 @@ public struct _UnitTestArrayBuffer<T> : _ArrayBufferType {
     /// the return from this function, as this implementation generates
     /// no shortcircuiting blocks.
     _precondition(_base.hasStorage, "Cannot index empty buffer")
-    return (index >= 0) & (index < _base.value.count)
+    return (index >= 0) && (index < _base.value.count)
   }
 
   /// How many elements the buffer can store without reallocation

stdlib/unittest/StdlibUnittest.swift.gyb

@@ -225,6 +225,7 @@ public func expectGE(
 public func expectType<T>(_: T.Type, inout x: T) {}
 
 public func isSequenceType<X : SequenceType>(x: X) -> X { return x }
+public func expectIsBooleanType<X : BooleanType>(inout x: X) -> X { return x }
 
 public struct AssertionResult : Printable, BooleanType {
   init(isPass: Bool) {

test/1_stdlib/Runtime.swift

@@ -991,7 +991,7 @@ Reflection.test("CustomMirror") {
     // Check the ObjectIdentifier created is stable
     expectTrue(
       (ObjectIdentifier(a) < ObjectIdentifier(b))
-      ^ (ObjectIdentifier(a) > ObjectIdentifier(b)))
+      != (ObjectIdentifier(a) > ObjectIdentifier(b)))
     expectFalse(
       ObjectIdentifier(a) >= ObjectIdentifier(b)
       && ObjectIdentifier(a) <= ObjectIdentifier(b))

test/expr/expressions.swift

@@ -445,17 +445,6 @@ func testInOut(inout arg: Int) {
   takesExplicitInt(5) // expected-error {{cannot invoke 'takesExplicitInt' with an argument list of type '(Int)'}} expected-note{{expected an argument list of type '(inout Int)'}}
 }
 
-//===----------------------------------------------------------------------===//
-// Bool operators
-//===----------------------------------------------------------------------===//
-
-func boolTest(a: Bool, b: Bool) {
-  var t1 = a != b
-  var t2 = a == b
-  var t3 = !a
-  var t4 = ~a
-}
-
 //===----------------------------------------------------------------------===//
 // Conversions
 //===----------------------------------------------------------------------===//

validation-test/stdlib/BoolDiagnostics.swift

@@ -0,0 +1,12 @@
+// RUN: %target-parse-verify-swift
+
+func test_removedOperators(a: Bool, b: Bool) {
+  var t1 = ~a // expected-error {{'~' is unavailable: use the '!' operator instead}}
+  var t2 = a & b // expected-error {{'&' is unavailable: use the '&&' operator instead}}
+  var t3 = a | b // expected-error {{'|' is unavailable: use the '||' operator instead}}
+  var t4 = a ^ b // expected-error {{'^' is unavailable: use the '!=' operator instead}}
+  t4 &= a // expected-error {{'&=' is unavailable: use the '&&' operator instead}}
+  t4 |= a // expected-error {{'|=' is unavailable: use the '||' operator instead}}
+  t4 ^= a // expected-error {{'^=' is unavailable: use the '!=' operator instead}}
+}
+

validation-test/stdlib/FixedPoint.swift.gyb

@@ -267,5 +267,100 @@ _UnimplementedError()
 
 #endif
 
+var BoolTestSuite = TestSuite("Bool")
+
+BoolTestSuite.test("literals") {
+  if true {
+    var v = false
+    expectType(Bool.self, &v)
+  }
+  if true {
+    var v = true
+    expectType(Bool.self, &v)
+  }
+}
+
+BoolTestSuite.test("init()") {
+  let v = Bool()
+  expectFalse(v)
+}
+
+struct Booleanish : BooleanType {
+  let boolValue: Bool
+}
+
+BoolTestSuite.test("init<T : BooleanType>(_:)") {
+  if true {
+    let v = Bool(Booleanish(boolValue: false))
+    expectFalse(v)
+  }
+  if true {
+    let v = Bool(Booleanish(boolValue: true))
+    expectTrue(v)
+  }
+}
+
+BoolTestSuite.test("BooleanType") {
+  if true {
+    var v: Bool = false
+    expectIsBooleanType(&v)
+    expectFalse(v.boolValue)
+  }
+  if true {
+    var v: Bool = true
+    expectTrue(v.boolValue)
+  }
+}
+
+BoolTestSuite.test("Printable") {
+  if true {
+    let v: Bool = false
+    expectEqual("false", toString(v))
+  }
+  if true {
+    let v: Bool = true
+    expectEqual("true", toString(v))
+  }
+}
+
+BoolTestSuite.test("Equatable,Hashable") {
+  checkHashable(true, false, false)
+  checkHashable(false, false, true)
+  checkHashable(true, true, true)
+
+  expectNotEqual(false.hashValue, true.hashValue)
+}
+
+BoolTestSuite.test("!") {
+  if true {
+    let v: Bool = false
+    var r = !v
+    expectType(Bool.self, &r)
+    expectTrue(r)
+  }
+  if true {
+    let v: Bool = true
+    var r = !v
+    expectType(Bool.self, &r)
+    expectFalse(r)
+  }
+}
+
+BoolTestSuite.test("!") {
+  let v: Bool = false
+  if true {
+    var r = (v == v)
+    expectType(Bool.self, &r)
+  }
+  if true {
+    var r = (v != v)
+    expectType(Bool.self, &r)
+  }
+  if true {
+    var r = !v
+    expectType(Bool.self, &r)
+  }
+}
+
 runAllTests()