[MIPS] Initial support for MIPS architecture.

llvm/lib/Target/Mips/MipsAsmPrinter.cpp

 //===-- MipsAsmPrinter.cpp - Mips LLVM assembly writer --------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains a printer that converts from our internal representation
@@ skipping 193 matching lines @@
   case MipsSubtarget::N64:  return "abi64";
   case MipsSubtarget::EABI: return "eabi32"; // TODO: handle eabi64
   default: break;
   }
 
   llvm_unreachable("Unknown Mips ABI");
   return NULL;
 }
 
 void MipsAsmPrinter::EmitFunctionEntryLabel() {
+  // @LOCALMOD-START
+  // make sure function entry is aligned. We use XmagicX as our basis
+  // for alignment decisions (c.f. assembler sfi macros).
+  int alignment = MF->getAlignment();
+  if (alignment < 4) alignment = 4;
+  EmitAlignment(alignment);
+  if (Subtarget->isTargetNaCl() && OutStreamer.hasRawTextSupport()) {
+    OutStreamer.EmitRawText(StringRef("\t.set XmagicX, .\n"));
+  }
+  // @LOCALMOD-END
+
   OutStreamer.EmitRawText("\t.ent\t" + Twine(CurrentFnSym->getName()));
   OutStreamer.EmitLabel(CurrentFnSym);
 }
 
 /// EmitFunctionBodyStart - Targets can override this to emit stuff before
 /// the first basic block in the function.
 void MipsAsmPrinter::EmitFunctionBodyStart() {
   emitFrameDirective();
 
   SmallString<128> Str;
@@ skipping 183 matching lines @@
   return;
 }
 
 void MipsAsmPrinter::
 printFCCOperand(const MachineInstr *MI, int opNum, raw_ostream &O,
                 const char *Modifier) {
   const MachineOperand& MO = MI->getOperand(opNum);
   O << Mips::MipsFCCToString((Mips::CondCode)MO.getImm());
 }
 
+// @LOCALMOD-START
+extern void EmitMipsSFIHeaders(raw_ostream &O);
+// @LOCALMOD-END
+
 void MipsAsmPrinter::EmitStartOfAsmFile(Module &M) {
   // FIXME: Use SwitchSection.
 
   // Tell the assembler which ABI we are using
   OutStreamer.EmitRawText("\t.section .mdebug." + Twine(getCurrentABIString()));
 
   // TODO: handle O64 ABI
   if (Subtarget->isABI_EABI()) {
     if (Subtarget->isGP32bit())
       OutStreamer.EmitRawText(StringRef("\t.section .gcc_compiled_long32"));
     else
       OutStreamer.EmitRawText(StringRef("\t.section .gcc_compiled_long64"));
   }
 
   // return to previous section
   OutStreamer.EmitRawText(StringRef("\t.previous"));
+
+  // @LOCALMOD-START
+  if (Subtarget->isTargetNaCl() && OutStreamer.hasRawTextSupport()) {
+    std::string str;
+    raw_string_ostream OS(str);
+    EmitMipsSFIHeaders(OS);
+    OutStreamer.EmitRawText(StringRef(OS.str()));
+  }
+  // @LOCALMOD-END
 }
 
+// @LOCALMOD-START
+unsigned MipsAsmPrinter::GetTargetLabelAlign(const MachineInstr *MI) const {
+  if (Subtarget->isTargetNaCl()) {
+    switch (MI->getOpcode()) {
+      default: return 0;
+      // These labels may indicate an indirect entry point that is
+      // externally reachable and hence must be bundle aligned.
+      // Note: these labels appear to be always at basic block beginnings
+      // so it may be possible to simply set the MBB alignment.
+      // However, it is unclear whether this always holds.
+      case TargetOpcode::EH_LABEL:
+      case TargetOpcode::GC_LABEL:
+        return 4;
+    }
+  }
+  return 0;
+}
+// @LOCALMOD-END
+
 MachineLocation
 MipsAsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
   // Handles frame addresses emitted in MipsInstrInfo::emitFrameIndexDebugValue.
   assert(MI->getNumOperands() == 4 && "Invalid no. of machine operands!");
   assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm() &&
          "Unexpected MachineOperand types");
   return MachineLocation(MI->getOperand(0).getReg(),
                          MI->getOperand(1).getImm());
 }
 
 void MipsAsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
                                            raw_ostream &OS) {
   // TODO: implement
 }
 
 // Force static initialization.
 extern "C" void LLVMInitializeMipsAsmPrinter() {
   RegisterAsmPrinter<MipsAsmPrinter> X(TheMipsTarget);
   RegisterAsmPrinter<MipsAsmPrinter> Y(TheMipselTarget);
   RegisterAsmPrinter<MipsAsmPrinter> A(TheMips64Target);
   RegisterAsmPrinter<MipsAsmPrinter> B(TheMips64elTarget);
 }