[IRGen] Use condbrs for big int switches.

lib/IRGen/EnumPayload.cpp

@@ -285,6 +285,24 @@ void EnumPayload::emitSwitch(IRGenFunction &IGF,
     return;
   }
 
+  if (mask.getBitWidth() > IGF.IGM.getPointerSize().getValueInBits() * 2) {
+    for (int index = 0, size = cases.size(); index < size; ++index) {
+      auto &c = cases[index];
+      auto *cmp = emitCompare(IGF, mask, c.first);
+      llvm::BasicBlock *elseBlock;
+      if (index < size - 1) {
+        elseBlock = IGF.createBasicBlock("");
+      } else {
+        elseBlock = dflt.getPointer();
+      }
+      IGF.Builder.CreateCondBr(cmp, c.second, elseBlock);
+      if (index < size - 1) {
+        IGF.Builder.emitBlock(elseBlock);
+      }
+    }
+    return;
+  }
+
   // Otherwise emit a switch statement.
   auto &C = IGF.IGM.getLLVMContext();
   unsigned numBits = mask.countPopulation();

test/IRGen/enum_large.swift

@@ -0,0 +1,61 @@
+// RUN: %swift-target-frontend -emit-irgen %s | %FileCheck %s
+
+// REQUIRES: PTRSIZE=64
+
+public struct SpareBits {
+    var o: UInt64 = 0
+    var x: UInt8 = 0
+    var y: UInt64 = 0
+    var x_2: UInt8 = 0
+    var y_2: UInt64 = 0
+    var x_3: UInt8 = 0
+    var y_3: UInt64 = 0
+    var x_4: UInt8 = 0
+    var y_4: UInt64 = 0
+    var x_5: UInt8 = 0
+    var y_5: UInt64 = 0
+    var x_6: UInt8 = 0
+    var y_6: UInt64 = 0
+}
+
+public class MyClass {}
+
+public enum Multipayload {
+    case a
+    case b(MyClass)
+    case c(SpareBits)
+    case e
+    case f
+    case g
+}
+
+@inline(never)
+func dump<T>(_ t : T) {}
+func dumpInt(_ i: Int) {}
+
+// CHECK-LABEL: define{{.*}} @"$s10enum_large6testIt1eyAA12MultipayloadO_tF"{{.*}}{
+// CHECK:         switch i8 {{%[^,]+}}, label {{%[^,]+}} [
+// CHECK:           i8 0, label {{%[^,]+}}
+// CHECK:           i8 1, label {{%[^,]+}}
+// CHECK:           i8 2, label %[[REGISTER_41:[^,]+]]
+// CHECK:       [[REGISTER_41]]:
+// CHECK:         br i1 {{%[^,]+}}, label {{%[^,]+}}, label %[[REGISTER_67:[^,]+]]
+// CHECK:       [[REGISTER_67]]:
+// CHECK:         br i1 {{%[^,]+}}, label {{%[^,]+}}, label %[[REGISTER_93:[^,]+]]
+// CHECK:       [[REGISTER_93]]:
+// CHECK:         br i1 {{%[^,]+}}, label {{%[^,]+}}, label %[[REGISTER_119:[^,]+]]
+// CHECK:       [[REGISTER_119]]:
+// CHECK:         br i1 {{%[^,]+}}, label %[[REGISTER_149:[^,]+]], label {{%[^,]+}}
+// CHECK:       [[REGISTER_149]]
+// CHECK:         call swiftcc void @"$s10enum_large7dumpIntyySiF"(i64 8675309)
+public func testIt(e : Multipayload) {
+    switch e {
+        case .a, .e, .f, .g:
+          dumpInt(8675309)
+        case .b(let c):
+          dump(c)
+        case .c(let s):
+          dump(s)
+    }
+}
+

validation-test/IRGen/rdar83158525.swift

@@ -0,0 +1,63 @@
+// RUN: %target-run-simple-swift | %FileCheck %s
+// REQUIRES: executable_test
+
+public struct SpareBits {
+    var o: UInt64 = 0
+    var x: UInt8 = 0
+    var y: UInt64 = 0
+    var x_2: UInt8 = 0
+    var y_2: UInt64 = 0
+    var x_3: UInt8 = 0
+    var y_3: UInt64 = 0
+    var x_4: UInt8 = 0
+    var y_4: UInt64 = 0
+    var x_5: UInt8 = 0
+    var y_5: UInt64 = 0
+    var x_6: UInt8 = 0
+    var y_6: UInt64 = 0
+}
+
+public class MyClass {}
+
+public enum Multipayload {
+    case a
+    case b(MyClass)
+    case c(SpareBits)
+    case e
+    case f
+    case g
+}
+
+public func testIt(_ e : Multipayload) {
+    switch e {
+        case .a:
+          print(".a (no payload)")
+        case .e:
+          print(".e (no payload)")
+        case .f:
+          print(".f (no payload)")
+        case .g:
+          print(".g (no payload)")
+        case .b(let s):
+          print(".b(\(s))")
+        case .c(let x):
+          print(".c(\(x))")
+    }
+}
+
+func doit() {
+  testIt(Multipayload.a)
+  testIt(Multipayload.e)
+  testIt(Multipayload.f)
+  testIt(Multipayload.g)
+  testIt(Multipayload.b(MyClass()))
+  testIt(Multipayload.c(SpareBits()))
+}
+doit()
+
+// CHECK: .a (no payload)
+// CHECK: .e (no payload)
+// CHECK: .f (no payload)
+// CHECK: .g (no payload)
+// CHECK: .b(main.MyClass)
+// CHECK: .c(SpareBits(o: 0, x: 0, y: 0, x_2: 0, y_2: 0, x_3: 0, y_3: 0, x_4: 0, y_4: 0, x_5: 0, y_5: 0, x_6: 0, y_6: 0))