1 files changed, 115 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/contrib/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
new file mode 100644
index 0000000..022a448
--- /dev/null
+++ b/contrib/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
@@ -0,0 +1,115 @@
+// 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 "WebAssemblyMachineFunctionInfo.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/IR/Constants.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());
+}
+
+MCSymbol *WebAssemblyMCInstLower::GetExternalSymbolSymbol(
+    const MachineOperand &MO) const {
+  return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
+}
+
+MCOperand WebAssemblyMCInstLower::LowerSymbolOperand(MCSymbol *Sym,
+                                                     int64_t Offset,
+                                                     bool IsFunc) const {
+  MCSymbolRefExpr::VariantKind VK =
+      IsFunc ? MCSymbolRefExpr::VK_WebAssembly_FUNCTION
+             : MCSymbolRefExpr::VK_None;
+  const MCExpr *Expr = MCSymbolRefExpr::create(Sym, VK, Ctx);
+
+  if (Offset != 0) {
+    if (IsFunc)
+      report_fatal_error("Function addresses with offsets not supported");
+    Expr =
+        MCBinaryExpr::createAdd(Expr, MCConstantExpr::create(Offset, Ctx), Ctx);
+  }
+
+  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_MachineBasicBlock:
+      MI->dump();
+      llvm_unreachable("MachineBasicBlock operand should have been rewritten");
+    case MachineOperand::MO_Register: {
+      // Ignore all implicit register operands.
+      if (MO.isImplicit())
+        continue;
+      const WebAssemblyFunctionInfo &MFI =
+          *MI->getParent()->getParent()->getInfo<WebAssemblyFunctionInfo>();
+      unsigned WAReg = MFI.getWAReg(MO.getReg());
+      MCOp = MCOperand::createReg(WAReg);
+      break;
+    }
+    case MachineOperand::MO_Immediate:
+      MCOp = MCOperand::createImm(MO.getImm());
+      break;
+    case MachineOperand::MO_FPImmediate: {
+      // TODO: MC converts all floating point immediate operands to double.
+      // This is fine for numeric values, but may cause NaNs to change bits.
+      const ConstantFP *Imm = MO.getFPImm();
+      if (Imm->getType()->isFloatTy())
+        MCOp = MCOperand::createFPImm(Imm->getValueAPF().convertToFloat());
+      else if (Imm->getType()->isDoubleTy())
+        MCOp = MCOperand::createFPImm(Imm->getValueAPF().convertToDouble());
+      else
+        llvm_unreachable("unknown floating point immediate type");
+      break;
+    }
+    case MachineOperand::MO_GlobalAddress:
+      assert(MO.getTargetFlags() == 0 &&
+             "WebAssembly does not use target flags on GlobalAddresses");
+      MCOp = LowerSymbolOperand(GetGlobalAddressSymbol(MO), MO.getOffset(),
+                                MO.getGlobal()->getValueType()->isFunctionTy());
+      break;
+    case MachineOperand::MO_ExternalSymbol:
+      // The target flag indicates whether this is a symbol for a
+      // variable or a function.
+      assert((MO.getTargetFlags() & -2) == 0 &&
+             "WebAssembly uses only one target flag bit on ExternalSymbols");
+      MCOp = LowerSymbolOperand(GetExternalSymbolSymbol(MO), /*Offset=*/0,
+                                MO.getTargetFlags() & 1);
+      break;
+    }
+
+    OutMI.addOperand(MCOp);
+  }
+}