ldc/gen/target.cpp

//===-- target.cpp -------------------------------------------------------===//
//
//                         LDC – the LLVM D compiler
//
// This file is distributed under the BSD-style LDC license. See the LICENSE
// file for details.
//
//===----------------------------------------------------------------------===//

#include "ldcbindings.h"
#include "target.h"
#include "gen/abi.h"
#include "gen/irstate.h"
#include "gen/llvmhelpers.h"
#include "mars.h"
#include "mtype.h"
#include <assert.h>

#if !defined(_MSC_VER)
#include <pthread.h>
#endif

/*
These guys are allocated by ddmd/target.d:
int Target::ptrsize;
int Target::realsize;
int Target::realpad;
int Target::realalignsize;
int Target::c_longsize;
int Target::c_long_doublesize;
bool Target::reverseCppOverloads;
*/

void Target::_init() {
  ptrsize = gDataLayout->getPointerSize(ADDRESS_SPACE);

  llvm::Type *real = DtoType(Type::basic[Tfloat80]);
  realsize = gDataLayout->getTypeAllocSize(real);
  realpad = realsize - gDataLayout->getTypeStoreSize(real);
  realalignsize = gDataLayout->getABITypeAlignment(real);
  c_longsize = global.params.is64bit ? 8 : 4;
  c_long_doublesize = realsize;

  // according to DMD, only for MSVC++:
  reverseCppOverloads = global.params.targetTriple->isWindowsMSVCEnvironment();

  // LDC_FIXME: Set once we support it.
  cppExceptions = false;
}

/******************************
 * Return memory alignment size of type.
 */
unsigned Target::alignsize(Type *type) {
  assert(type->isTypeBasic());
  if (type->ty == Tvoid) {
    return 1;
  }
  return gDataLayout->getABITypeAlignment(DtoType(type));
}

/******************************
 * Return field alignment size of type.
 */
unsigned Target::fieldalign(Type *type) { return DtoAlignment(type); }

/******************************
 * Return size of alias Mutex in druntime/src/rt/monitor_.d, or, more precisely,
 * the size of the native critical section as 2nd field in struct
 * D_CRITICAL_SECTION (after a pointer). D_CRITICAL_SECTION is pointer-size
 * aligned, so the returned field size is a multiple of pointer-size.
 */
unsigned Target::critsecsize() {
  const bool is64bit = global.params.is64bit;

  // Windows: sizeof(CRITICAL_SECTION)
  if (global.params.isWindows)
    return is64bit ? 40 : 24;

  // POSIX: sizeof(pthread_mutex_t)
  // based on druntime/src/core/sys/posix/sys/types.d
  const auto &triple = *global.params.targetTriple;
  const auto arch = triple.getArch();
  switch (triple.getOS()) {
  case llvm::Triple::Linux:
    if (triple.getEnvironment() == llvm::Triple::Android)
      return Target::ptrsize; // 32-bit integer rounded up to pointer size
    if (arch == llvm::Triple::aarch64 || arch == llvm::Triple::aarch64_be)
      return 48;
    return is64bit ? 40 : 24;

  case llvm::Triple::MacOSX:
    return is64bit ? 64 : 44;

  case llvm::Triple::FreeBSD:
  case llvm::Triple::NetBSD:
  case llvm::Triple::OpenBSD:
  case llvm::Triple::DragonFly:
    return Target::ptrsize;

  case llvm::Triple::Solaris:
    return 24;

  default:
    break;
  }

#ifndef _MSC_VER
  unsigned hostSize = sizeof(pthread_mutex_t);
  warning(Loc(), "Assuming critical section size = %u bytes", hostSize);
  return hostSize;
#else
  error(Loc(), "Unknown critical section size");
  fatal();
  return 0;
#endif
}

Type *Target::va_listType() { return gABI->vaListType(); }

/******************************
 * Encode the given expression, which is assumed to be an rvalue literal
 * as another type for use in CTFE.
 * This corresponds roughly to the idiom *(Type *)&e.
 */
Expression *Target::paintAsType(Expression *e, Type *type) {
  union {
    d_int32 int32value;
    d_int64 int64value;
    float float32value;
    double float64value;
  } u;

  assert(e->type->size() == type->size());

  switch (e->type->ty) {
  case Tint32:
  case Tuns32:
    u.int32value = static_cast<d_int32>(e->toInteger());
    break;

  case Tint64:
  case Tuns64:
    u.int64value = static_cast<d_int64>(e->toInteger());
    break;

  case Tfloat32:
    u.float32value = e->toReal();
    break;

  case Tfloat64:
    u.float64value = e->toReal();
    break;

  default:
    assert(0);
  }

  switch (type->ty) {
  case Tint32:
  case Tuns32:
    return createIntegerExp(e->loc, u.int32value, type);

  case Tint64:
  case Tuns64:
    return createIntegerExp(e->loc, u.int64value, type);

  case Tfloat32:
    return createRealExp(e->loc, ldouble(u.float32value), type);

  case Tfloat64:
    return createRealExp(e->loc, ldouble(u.float64value), type);

  default:
    assert(0);
  }

  return nullptr; // avoid warning
}

/******************************
 * Check if the given type is supported for this target
 * 0: supported
 * 1: not supported
 * 2: wrong size
 * 3: wrong base type
 */
int Target::checkVectorType(int sz, Type *type) {
  // FIXME: It is possible to query the LLVM target about supported vectors?
  return 0;
}

/******************************
 * For the given module, perform any post parsing analysis.
 * Certain compiler backends (ie: GDC) have special placeholder
 * modules whose source are empty, but code gets injected
 * immediately after loading.
 */
void Target::loadModule(Module *m) {}

/******************************
 *
 */
void Target::prefixName(OutBuffer *buf, LINK linkage) {}