Part 4c: Coroutine Devirtualization: Devirtualize coro.resume and coro.destroy.

Summary:
This is the 4c patch of the coroutine series. CoroElide pass now checks if PostSplit coro.begin
is referenced by coro.subfn.addr intrinsics. If so replace coro.subfn.addrs with an appropriate coroutine
subfunction associated with that coro.begin.

Documentation and overview is here: http://llvm.org/docs/Coroutines.html.

Upstreaming sequence (rough plan)
1.Add documentation. (https://reviews.llvm.org/D22603)
2.Add coroutine intrinsics. (https://reviews.llvm.org/D22659)
3.Add empty coroutine passes. (https://reviews.llvm.org/D22847)
4.Add coroutine devirtualization + tests.
ab) Lower coro.resume and coro.destroy (https://reviews.llvm.org/D22998)
c) Do devirtualization <= we are here
5.Add CGSCC restart trigger + tests.
6.Add coroutine heap elision + tests.
7.Add the rest of the logic (split into more patches)

Reviewers: majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23229

llvm-svn: 277908

1 files changed, 14 insertions, 0 deletions

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 2b6bd3aa64f..05140403116 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -3837,6 +3837,20 @@ void Verifier::visitIntrinsicCallSite(Intrinsic::ID ID, CallSite CS) {
   switch (ID) {
   default:
     break;
+  case Intrinsic::coro_begin: {
+    auto *InfoArg = CS.getArgOperand(3)->stripPointerCasts();
+    if (isa<ConstantPointerNull>(InfoArg))
+      break;
+    auto *GV = dyn_cast<GlobalVariable>(InfoArg);
+    Assert(GV && GV->isConstant() && GV->hasDefinitiveInitializer(),
+      "info argument of llvm.coro.begin must refer to an initialized "
+      "constant");
+    Constant *Init = GV->getInitializer();
+    Assert(isa<ConstantStruct>(Init) || isa<ConstantArray>(Init),
+      "info argument of llvm.coro.begin must refer to either a struct or "
+      "an array");
+    break;
+  }
   case Intrinsic::ctlz:  // llvm.ctlz
   case Intrinsic::cttz:  // llvm.cttz
     Assert(isa<ConstantInt>(CS.getArgOperand(1)),