Disable tail calls if there is an swifterror argument

ISel does not handle them correctly yet i.e we crash trying to emit tail call
code.

radar://28407842

llvm-svn: 282088

4 files changed, 41 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index ceabccca2ab..a0db9ae34f8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5833,6 +5833,11 @@ void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee,
   if (isTailCall && !isInTailCallPosition(CS, DAG.getTarget()))
     isTailCall = false;
 
+  // Disable tail calls if there is an swifterror argument. Targets have not
+  // been updated to support tail calls.
+  if (TLI.supportSwiftError() && SwiftErrorVal)
+    isTailCall = false;
+
   TargetLowering::CallLoweringInfo CLI(DAG);
   CLI.setDebugLoc(getCurSDLoc())
       .setChain(getRoot())
diff --git a/llvm/test/CodeGen/AArch64/swifterror.ll b/llvm/test/CodeGen/AArch64/swifterror.ll
index a0bfffdef95..507ae4d37d5 100644
--- a/llvm/test/CodeGen/AArch64/swifterror.ll
+++ b/llvm/test/CodeGen/AArch64/swifterror.ll
@@ -383,3 +383,15 @@ handler:
   call void @free(i8* %tmp)
   ret float 1.0
 }
+
+; Check that we don't blow up on tail calling swifterror argument functions.
+define float @tailcallswifterror(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  %0 = tail call float @tailcallswifterror(%swift_error** swifterror %error_ptr_ref)
+  ret float %0
+}
+define swiftcc float @tailcallswifterror_swiftcc(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  %0 = tail call swiftcc float @tailcallswifterror_swiftcc(%swift_error** swifterror %error_ptr_ref)
+  ret float %0
+}
diff --git a/llvm/test/CodeGen/ARM/swifterror.ll b/llvm/test/CodeGen/ARM/swifterror.ll
index 17bd7059f6d..29cd2ffc281 100644
--- a/llvm/test/CodeGen/ARM/swifterror.ll
+++ b/llvm/test/CodeGen/ARM/swifterror.ll
@@ -379,3 +379,15 @@ handler:
   call void @free(i8* %tmp)
   ret float 1.0
 }
+
+; Check that we don't blow up on tail calling swifterror argument functions.
+define float @tailcallswifterror(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  %0 = tail call float @tailcallswifterror(%swift_error** swifterror %error_ptr_ref)
+  ret float %0
+}
+define swiftcc float @tailcallswifterror_swiftcc(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  %0 = tail call swiftcc float @tailcallswifterror_swiftcc(%swift_error** swifterror %error_ptr_ref)
+  ret float %0
+}
diff --git a/llvm/test/CodeGen/X86/swifterror.ll b/llvm/test/CodeGen/X86/swifterror.ll
index b1e82e54328..b7226eb2b4e 100644
--- a/llvm/test/CodeGen/X86/swifterror.ll
+++ b/llvm/test/CodeGen/X86/swifterror.ll
@@ -466,3 +466,15 @@ gen_error:
 normal:
   ret float 0.0
 }
+
+; Check that we don't blow up on tail calling swifterror argument functions.
+define float @tailcallswifterror(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  %0 = tail call float @tailcallswifterror(%swift_error** swifterror %error_ptr_ref)
+  ret float %0
+}
+define swiftcc float @tailcallswifterror_swiftcc(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  %0 = tail call swiftcc float @tailcallswifterror_swiftcc(%swift_error** swifterror %error_ptr_ref)
+  ret float %0
+}