path: root/utils/TableGen/NeonEmitter.cpp

//===- NeonEmitter.cpp - Generate arm_neon.h for use with clang -*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This tablegen backend is responsible for emitting arm_neon.h, which includes
// a declaration and definition of each function specified by the ARM NEON 
// compiler interface.  See ARM document DUI0348B.
//
//===----------------------------------------------------------------------===//

#include "NeonEmitter.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include <string>

using namespace llvm;

static void ParseTypes(Record *r, std::string &s,
                       SmallVectorImpl<StringRef> &TV) {
  const char *data = s.data();
  int len = 0;
  
  for (unsigned i = 0, e = s.size(); i != e; ++i, ++len) {
    if (data[len] == 'P' || data[len] == 'Q' || data[len] == 'U')
      continue;
    
    switch (data[len]) {
      case 'c':
      case 's':
      case 'i':
      case 'l':
      case 'h':
      case 'f':
        break;
      default:
        throw TGError(r->getLoc(),
                      "Unexpected letter: " + std::string(data + len, 1));
        break;
    }
    TV.push_back(StringRef(data, len + 1));
    data += len + 1;
    len = -1;
  }
}

static char Widen(const char t) {
  switch (t) {
    case 'c':
      return 's';
    case 's':
      return 'i';
    case 'i':
      return 'l';
    default: throw "unhandled type in widen!";
  }
  return '\0';
}

static char Narrow(const char t) {
  switch (t) {
    case 's':
      return 'c';
    case 'i':
      return 's';
    case 'l':
      return 'i';
    case 'f':
      return 'h';
    default: throw "unhandled type in widen!";
  }
  return '\0';
}

static char ClassifyType(StringRef ty, bool &quad, bool &poly, bool &usgn) {
  unsigned off = 0;
  
  // remember quad.
  if (ty[off] == 'Q') {
    quad = true;
    ++off;
  }
  
  // remember poly.
  if (ty[off] == 'P') {
    poly = true;
    ++off;
  }
  
  // remember unsigned.
  if (ty[off] == 'U') {
    usgn = true;
    ++off;
  }
  
  // base type to get the type string for.
  return ty[off];
}

static char ModType(const char mod, char type, bool &quad, bool &poly,
                    bool &usgn, bool &scal, bool &cnst, bool &pntr) {
  switch (mod) {
    case 't':
      if (poly) {
        poly = false;
        usgn = true;
      }
      break;
    case 'u':
      usgn = true;
    case 'x':
      poly = false;
      if (type == 'f')
        type = 'i';
      break;
    case 'f':
      if (type == 'h')
        quad = true;
      type = 'f';
      usgn = false;
      break;
    case 'w':
      type = Widen(type);
      quad = true;
      break;
    case 'n':
      type = Widen(type);
      break;
    case 'l':
      type = 'l';
      scal = true;
      usgn = true;
      break;
    case 's':
      scal = true;
      break;
    case 'k':
      quad = true;
      break;
    case 'c':
      cnst = true;
    case 'p':
      usgn = false;
      poly = false;
      pntr = true;
      scal = true;
      break;
    case 'h':
      type = Narrow(type);
      if (type == 'h')
        quad = false;
      break;
    case 'e':
      type = Narrow(type);
      usgn = true;
      break;
    default:
      break;
  }
  return type;
}

static std::string TypeString(const char mod, StringRef typestr,
                              bool