1 files changed, 39 insertions, 23 deletions

diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
index fc96ef2bf5b..f409bd77442 100644
--- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
+++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCFixup.h"
@@ -26,30 +27,26 @@ using namespace llvm;
 
 #define DEBUG_TYPE "mccodeemitter"
 
+STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
+STATISTIC(MCNumFixups, "Number of MC fixups created.");
+
 namespace {
 class WebAssemblyMCCodeEmitter final : public MCCodeEmitter {
-public:
-  WebAssemblyMCCodeEmitter(const MCInstrInfo &, MCContext &) {}
+  const MCInstrInfo &MCII;
+  const MCContext &Ctx;
 
-  /// TableGen'erated function for getting the binary encoding for an
-  /// instruction.
+  // Implementation generated by tablegen.
   uint64_t getBinaryCodeForInstr(const MCInst &MI,
                                  SmallVectorImpl<MCFixup> &Fixups,
                                  const MCSubtargetInfo &STI) const;
 
-  /// Return binary encoding of operand. If the machine operand requires
-  /// relocation, record the relocation and return zero.
-  unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO,
-                             SmallVectorImpl<MCFixup> &Fixups,
-                             const MCSubtargetInfo &STI) const;
-
-  uint64_t getMemoryOpValue(const MCInst &MI, unsigned Op,
-                            SmallVectorImpl<MCFixup> &Fixups,
-                            const MCSubtargetInfo &STI) const;
-
   void encodeInstruction(const MCInst &MI, raw_ostream &OS,
                          SmallVectorImpl<MCFixup> &Fixups,
                          const MCSubtargetInfo &STI) const override;
+
+public:
+  WebAssemblyMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
+      : MCII(mcii), Ctx(ctx) {}
 };
 } // end anonymous namespace
 
@@ -61,16 +58,35 @@ MCCodeEmitter *llvm::createWebAssemblyMCCodeEmitter(const MCInstrInfo &MCII,
 void WebAssemblyMCCodeEmitter::encodeInstruction(
     const MCInst &MI, raw_ostream &OS, SmallVectorImpl<MCFixup> &Fixups,
     const MCSubtargetInfo &STI) const {
-  assert(false && "FIXME: not implemented yet");
-}
+  // FIXME: This is not the real binary encoding. This is an extremely
+  // over-simplified encoding where we just use uint64_t for everything. This
+  // is a temporary measure.
+  support::endian::Writer<support::little>(OS).write<uint64_t>(MI.getOpcode());
+  const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
+  if (Desc.isVariadic())
+    support::endian::Writer<support::little>(OS).write<uint64_t>(
+        MI.getNumOperands() - Desc.NumOperands);
+  for (unsigned i = 0, e = MI.getNumOperands(); i < e; ++i) {
+    const MCOperand &MO = MI.getOperand(i);
+    if (MO.isReg()) {
+      support::endian::Writer<support::little>(OS).write<uint64_t>(MO.getReg());
+    } else if (MO.isImm()) {
+      support::endian::Writer<support::little>(OS).write<uint64_t>(MO.getImm());
+    } else if (MO.isFPImm()) {
+      support::endian::Writer<support::little>(OS).write<double>(MO.getFPImm());
+    } else if (MO.isExpr()) {
+      support::endian::Writer<support::little>(OS).write<uint64_t>(0);
+      Fixups.push_back(MCFixup::create(
+          (1 + MCII.get(MI.getOpcode()).isVariadic() + i) * sizeof(uint64_t),
+          MO.getExpr(), STI.getTargetTriple().isArch64Bit() ? FK_Data_8 : FK_Data_4,
+          MI.getLoc()));
+      ++MCNumFixups;
+    } else {
+      llvm_unreachable("unexpected operand kind");
+    }
+  }
 
-// Encode WebAssembly Memory Operand
-uint64_t
-WebAssemblyMCCodeEmitter::getMemoryOpValue(const MCInst &MI, unsigned Op,
-                                           SmallVectorImpl<MCFixup> &Fixups,
-                                           const MCSubtargetInfo &STI) const {
-  assert(false && "FIXME: not implemented yet");
-  return 0;
+  ++MCNumEmitted; // Keep track of the # of mi's emitted.
 }
 
 #include "WebAssemblyGenMCCodeEmitter.inc"