swiftcc: Don't emit tail calls from callers with swifterror parameters

Backends don't support this yet. They would have to move to the swifterror
register before the tail call to make sure it is live-in to the call.

rdar://30495920

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294982 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 5966069d31b5159604d418ff43a78bbb92ce59f1..d59419ec09f3c7433793c6e7359edd3d7807045a 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5916,6 +5916,15 @@ void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee,
 
   const Value *SwiftErrorVal = nullptr;
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
+
+  // We can't tail call inside a function with a swifterror argument. Lowering
+  // does not support this yet. It would have to move into the swifterror
+  // register before the call.
+  auto *Caller = CS.getInstruction()->getParent()->getParent();
+  if (TLI.supportSwiftError() &&
+      Caller->getAttributes().hasAttrSomewhere(Attribute::SwiftError))
+    isTailCall = false;
+
   for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
        i != e; ++i) {
     const Value *V = *i;

diff --git a/test/CodeGen/AArch64/swifterror.ll b/test/CodeGen/AArch64/swifterror.ll
index 016af2a1069031c2a1a76289e22f610ac5dc87e6..69bf3510cc5a72594daf924763012347bebc845b 100644 (file)
--- a/test/CodeGen/AArch64/swifterror.ll
+++ b/test/CodeGen/AArch64/swifterror.ll
@@ -583,3 +583,17 @@ define swiftcc { i64, i64, i64, i64, i64, i64, i64, i64 } @params_and_return_in_
 }
 
 declare swiftcc { i64, i64, i64, i64, i64, i64, i64, i64 } @params_and_return_in_reg2(i64, i64, i64, i64, i64, i64, i64, i64, i8* swiftself, %swift_error** nocapture swifterror %err)
+
+declare void @acallee(i8*)
+
+; Make sure we don't tail call if the caller returns a swifterror value. We
+; would have to move into the swifterror register before the tail call.
+; CHECK-APPLE: tailcall_from_swifterror:
+; CHECK-APPLE-NOT: b _acallee
+; CHECK-APPLE: bl _acallee
+
+define swiftcc void @tailcall_from_swifterror(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  tail call void @acallee(i8* null)
+  ret void
+}

diff --git a/test/CodeGen/ARM/swifterror.ll b/test/CodeGen/ARM/swifterror.ll
index 45a864d1af1330562cb0cabaaa43f405c330f87e..78764202f62730ad6699ea6ef74970e6f0819651 100644 (file)
--- a/test/CodeGen/ARM/swifterror.ll
+++ b/test/CodeGen/ARM/swifterror.ll
@@ -513,3 +513,18 @@ define swiftcc { i32, i32, i32, i32} @params_and_return_in_reg(i32, i32, i32, i3
 }
 
 declare swiftcc { i32, i32, i32, i32 } @params_and_return_in_reg2(i32, i32, i32, i32, i8* swiftself, %swift_error** nocapture swifterror %err)
+
+
+declare void @acallee(i8*)
+
+; Make sure we don't tail call if the caller returns a swifterror value. We
+; would have to move into the swifterror register before the tail call.
+; CHECK-APPLE: tailcall_from_swifterror:
+; CHECK-APPLE-NOT: b _acallee
+; CHECK-APPLE: bl _acallee
+
+define swiftcc void @tailcall_from_swifterror(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  tail call void @acallee(i8* null)
+  ret void
+}

diff --git a/test/CodeGen/X86/swifterror.ll b/test/CodeGen/X86/swifterror.ll
index cd4150597225273c63fc5f733af9e94ee5d1f12b..86e0221c20151ebab05dec70f4c12ca7cebe57ab 100644 (file)
--- a/test/CodeGen/X86/swifterror.ll
+++ b/test/CodeGen/X86/swifterror.ll
@@ -670,3 +670,18 @@ define swiftcc { i64, i64, i64, i64} @params_and_return_in_reg(i64, i64, i64, i6
 }
 
 declare swiftcc { i64, i64, i64, i64 } @params_and_return_in_reg2(i64, i64, i64, i64, i64, i64, i8* swiftself, %swift_error** nocapture swifterror %err)
+
+
+declare void @acallee(i8*)
+
+; Make sure we don't tail call if the caller returns a swifterror value. We
+; would have to move into the swifterror register before the tail call.
+; CHECK-APPLE: tailcall_from_swifterror:
+; CHECK-APPLE-NOT: jmp _acallee
+; CHECK-APPLE: callq _acallee
+
+define swiftcc void @tailcall_from_swifterror(%swift_error** swifterror %error_ptr_ref) {
+entry:
+  tail call void @acallee(i8* null)
+  ret void
+}