[WebAssembly] Add WebAssemblyMCInstLower.cpp.

[oota-llvm.git] / lib / Target / WebAssembly / WebAssemblyMCInstLower.cpp

diff --git a/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
new file mode 100644 (file)
index 0000000..59acbdb
--- /dev/null
+++ b/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
@@ -0,0 +1,84 @@
+// WebAssemblyMCInstLower.cpp - Convert WebAssembly MachineInstr to an MCInst //
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief This file contains code to lower WebAssembly MachineInstrs to their
+/// corresponding MCInst records.
+///
+//===----------------------------------------------------------------------===//
+
+#include "WebAssemblyMCInstLower.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+MCSymbol *
+WebAssemblyMCInstLower::GetGlobalAddressSymbol(const MachineOperand &MO) const {
+  return Printer.getSymbol(MO.getGlobal());
+}
+
+MCOperand WebAssemblyMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
+                                                     MCSymbol *Sym) const {
+
+  const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
+
+  if (!MO.isJTI() && MO.getOffset())
+    llvm_unreachable("unknown symbol op");
+
+  return MCOperand::createExpr(Expr);
+}
+
+void WebAssemblyMCInstLower::Lower(const MachineInstr *MI,
+                                   MCInst &OutMI) const {
+  OutMI.setOpcode(MI->getOpcode());
+
+  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+    const MachineOperand &MO = MI->getOperand(i);
+
+    MCOperand MCOp;
+    switch (MO.getType()) {
+    default:
+      MI->dump();
+      llvm_unreachable("unknown operand type");
+    case MachineOperand::MO_Register:
+      // Ignore all implicit register operands.
+      if (MO.isImplicit())
+        continue;
+      MCOp = MCOperand::createReg(MO.getReg());
+      break;
+    case MachineOperand::MO_Immediate:
+      MCOp = MCOperand::createImm(MO.getImm());
+      break;
+    case MachineOperand::MO_FPImmediate:
+      MCOp = MCOperand::createFPImm(
+          MO.getFPImm()->getValueAPF().convertToDouble());
+      break;
+    case MachineOperand::MO_MachineBasicBlock:
+      MCOp = MCOperand::createExpr(
+          MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
+      break;
+    case MachineOperand::MO_RegisterMask:
+      continue;
+    case MachineOperand::MO_GlobalAddress:
+      MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
+      break;
+    }
+
+    OutMI.addOperand(MCOp);
+  }
+}