Merge pull request #15470 from moiseev/proto-dw

[stdlib] Move DoubleWidth to test/Prototypes

Author: moiseev

stdlib/public/core/CMakeLists.txt

@@ -48,7 +48,6 @@ set(SWIFTLIB_ESSENTIAL
   CTypes.swift
   DebuggerSupport.swift
   Dictionary.swift
-  DoubleWidth.swift.gyb
   DropWhile.swift
   Dump.swift
   EmptyCollection.swift

stdlib/public/core/GroupInfo.json

@@ -134,7 +134,6 @@
     "BuiltinMath.swift",
     {
     "Integers": [
-      "DoubleWidth.swift",
       "Integers.swift",
       "IntegerParsing.swift"],
     "Floating": [

stdlib/public/core/Integers.swift.gyb

@@ -3552,23 +3552,11 @@ ${assignmentOperatorComment(x.operator, True)}
   ) -> (quotient: ${Self}, remainder: ${Self}) {
     // FIXME(integers): tests
 %   # 128-bit types are not provided by the 32-bit LLVM
-%   #if word_bits == 32 and bits == 64:
+%   if word_bits == 32 and bits == 64:
 %   # FIXME(integers): uncomment the above after using the right conditional
 %   # compilation block to exclude 64-bit Windows, which does not support
 %   # 128-bit operations
-%   if bits == 64:
-%     HalfWidth = 'Int32' if signed else 'UInt32'
-    let lhsHigh =
-      unsafeBitCast(dividend.high, to: DoubleWidth<${HalfWidth}>.self)
-    let lhsLow = unsafeBitCast(dividend.low, to: DoubleWidth<UInt32>.self)
-    let rhs_ = unsafeBitCast(self, to: DoubleWidth<${HalfWidth}>.self)
-
-    let (quotient_, remainder_) = rhs_.dividingFullWidth((lhsHigh, lhsLow))
-
-    let quotient = unsafeBitCast(quotient_, to: ${Self}.self)
-    let remainder = unsafeBitCast(remainder_, to: ${Self}.self)
-
-    return (quotient: quotient, remainder: remainder)
+    fatalError("Operation is not supported")
 %   else:
     // FIXME(integers): handle division by zero and overflows
     _precondition(self != 0, "Division by zero")

test/Constraints/diagnostics_swift4.swift

@@ -54,4 +54,5 @@ class R<K: Hashable, V> {
 infix operator +=+ : AdditionPrecedence
 func +=+(_ lhs: Int, _ rhs: Int) -> Bool { return lhs == rhs }
 func +=+<T: BinaryInteger>(_ lhs: T, _ rhs: Int) -> Bool { return lhs == rhs }
-let _ = DoubleWidth<Int>(Int.min) - 1 +=+ Int.min // Ok
+// FIXME: DoubleWidth is no longer part of the standard library
+// let _ = DoubleWidth<Int>(Int.min) - 1 +=+ Int.min // Ok