[WebAssemby] Implement block signatures.

Per spec changes, this implements block signatures, and adds just enough
logic to produce correct block signatures at the ends of functions.

Differential Revision: https://reviews.llvm.org/D25144

llvm-svn: 283503

1 files changed, 10 insertions, 3 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 931e2ada050..fb84aa94350 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -481,12 +481,12 @@ SDValue WebAssemblyTargetLowering::LowerFormalArguments(
     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
-  MachineFunction &MF = DAG.getMachineFunction();
-  auto *MFI = MF.getInfo<WebAssemblyFunctionInfo>();
-
   if (!CallingConvSupported(CallConv))
     fail(DL, DAG, "WebAssembly doesn't support non-C calling conventions");
 
+  MachineFunction &MF = DAG.getMachineFunction();
+  auto *MFI = MF.getInfo<WebAssemblyFunctionInfo>();
+
   // Set up the incoming ARGUMENTS value, which serves to represent the liveness
   // of the incoming values before they're represented by virtual registers.
   MF.getRegInfo().addLiveIn(WebAssembly::ARGUMENTS);
@@ -526,6 +526,13 @@ SDValue WebAssemblyTargetLowering::LowerFormalArguments(
     MFI->addParam(PtrVT);
   }
 
+  // Record the number and types of results.
+  SmallVector<MVT, 4> Params;
+  SmallVector<MVT, 4> Results;
+  ComputeSignatureVTs(*MF.getFunction(), DAG.getTarget(), Params, Results);
+  for (MVT VT : Results)
+    MFI->addResult(VT);
+
   return Chain;
 }