Auto upgrade bitcode to new vararg representation for coro.id.retcon.once intrinsic

The signature of coro.id.retcon.once intrinsic was modified in swiftlang#10015
with an extra vararg. This commit adds an auto upgrader to LLVM in order to be compatible with compilers
generating old bitcode (intrinsic without the vararg).

rdar://147426562

Author: t-rasmud

llvm/lib/IR/AutoUpgrade.cpp

@@ -1073,6 +1073,13 @@ static bool upgradeIntrinsicFunction1(Function *F, Function *&NewFn,
       return true;
     }
 
+    if (F->arg_size() == 6 && Name == "coro.id.retcon.once") {
+      rename(F);
+      NewFn = Intrinsic::getDeclaration(F->getParent(),
+                                        Intrinsic::coro_id_retcon_once);
+      return true;
+    }
+
     break;
   }
   case 'd':
@@ -4409,6 +4416,12 @@ void llvm::UpgradeIntrinsicCall(CallBase *CI, Function *NewFn) {
     break;
   }
 
+  case Intrinsic::coro_id_retcon_once: {
+    SmallVector<Value *, 8> Args(CI->args());
+    NewCall = Builder.CreateCall(NewFn, Args);
+    break;
+  }
+
   case Intrinsic::vector_extract: {
     StringRef Name = F->getName();
     Name = Name.substr(5); // Strip llvm

llvm/test/Transforms/Coroutines/coro-retcon-frame-old.ll

@@ -0,0 +1,56 @@
+; RUN: opt < %s -passes='cgscc(coro-split),simplifycfg,early-cse' -S | FileCheck %s
+
+target datalayout = "p:64:64:64"
+
+declare void @prototype_f(ptr, i1)
+
+declare noalias ptr @allocate(i32 %size)
+declare void @deallocate(ptr %ptr)
+declare void @init(ptr %ptr)
+declare void @use(ptr %ptr)
+declare void @use_addr_val(i64 %val, ptr %addr)
+
+define { ptr, ptr } @f(ptr %buffer) presplitcoroutine {
+entry:
+  %tmp = alloca { i64, i64 }, align 8
+  %proj.1 = getelementptr inbounds { i64, i64 }, ptr %tmp, i64 0, i32 0
+  %proj.2 = getelementptr inbounds { i64, i64 }, ptr %tmp, i64 0, i32 1
+  store i64 0, ptr %proj.1, align 8
+  store i64 0, ptr %proj.2, align 8
+  %escape_addr = ptrtoint ptr %tmp to i64
+  %id = call token (i32, i32, ptr, ptr, ptr, ptr) @llvm.coro.id.retcon.once(i32 32, i32 8, ptr %buffer, ptr @prototype_f, ptr @allocate, ptr @deallocate)
+  %hdl = call ptr @llvm.coro.begin(token %id, ptr null)
+  %proj.2.2 = getelementptr inbounds { i64, i64 }, ptr %tmp, i64 0, i32 1
+  call void @init(ptr %proj.1)
+  call void @init(ptr %proj.2.2)
+  call void @use_addr_val(i64 %escape_addr, ptr %tmp)
+  %abort = call i1 (...) @llvm.coro.suspend.retcon.i1(ptr %tmp)
+  br i1 %abort, label %end, label %resume
+
+resume:
+  call void @use(ptr %tmp)
+  br label %end
+
+end:
+  call i1 @llvm.coro.end(ptr %hdl, i1 0, token none)
+  unreachable
+}
+; Make sure we don't lose writes to the frame.
+; CHECK-LABEL: define { ptr, ptr } @f(ptr %buffer) {
+; CHECK:  [[PROJ2:%.*]] = getelementptr inbounds { i64, i64 }, ptr %buffer, i64 0, i32 1
+; CHECK:  store i64 0, ptr %buffer
+; CHECK:  store i64 0, ptr [[PROJ2]]
+; CHECK:  [[ESCAPED_ADDR:%.*]] = ptrtoint ptr %buffer to i64
+; CHECK:  call void @init(ptr %buffer)
+; CHECK:  call void @init(ptr [[PROJ2]])
+; CHECK:  call void @use_addr_val(i64 [[ESCAPED_ADDR]], ptr %buffer)
+
+; CHECK-LABEL: define internal void @f.resume.0(ptr {{.*}} %0, i1 %1) {
+; CHECK: resume:
+; CHECK:  call void @use(ptr %0)
+
+declare token @llvm.coro.id.retcon.once(i32, i32, ptr, ptr, ptr, ptr)
+declare ptr @llvm.coro.begin(token, ptr)
+declare i1 @llvm.coro.suspend.retcon.i1(...)
+declare i1 @llvm.coro.end(ptr, i1, token)
+