[WebAssembly] Check in an initial CFG Stackifier pass

This pass implements a simple algorithm for conversion from CFG to
wasm's structured control flow. It doesn't yet handle multiple-entry
loops; that will be added in a future patch.

It also adds initial support for switch statements.

Differential Revision: http://reviews.llvm.org/D12735

llvm-svn: 247818

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
index fca3890de60..94ea1085ff4 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
@@ -73,6 +73,7 @@ private:
 
   void EmitGlobalVariable(const GlobalVariable *GV) override;
 
+  void EmitJumpTableInfo() override;
   void EmitConstantPool() override;
   void EmitFunctionEntryLabel() override;
   void EmitFunctionBodyStart() override;
@@ -213,6 +214,10 @@ void WebAssemblyAsmPrinter::EmitConstantPool() {
          "WebAssembly disables constant pools");
 }
 
+void WebAssemblyAsmPrinter::EmitJumpTableInfo() {
+  // Nothing to do; jump tables are incorporated into the instruction stream.
+}
+
 void WebAssemblyAsmPrinter::EmitFunctionEntryLabel() {
   SmallString<128> Str;
   raw_svector_ostream OS(Str);
@@ -293,6 +298,9 @@ void WebAssemblyAsmPrinter::EmitInstruction(const MachineInstr *MI) {
       case MachineOperand::MO_GlobalAddress: {
         OS << ' ' << toSymbol(MO.getGlobal()->getName());
       } break;
+      case MachineOperand::MO_MachineBasicBlock: {
+        OS << ' ' << toSymbol(MO.getMBB()->getSymbol()->getName());
+      } break;
       }
     OS << ')';
   }