code-gen-x64.h

/*
   +----------------------------------------------------------------------+
   | HipHop for PHP                                                       |
   +----------------------------------------------------------------------+
   | Copyright (c) 2010-2014 Facebook, Inc. (http://www.facebook.com)     |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
*/

#ifndef incl_HPHP_VM_CG_X64_H_
#define incl_HPHP_VM_CG_X64_H_

#include "hphp/runtime/vm/jit/code-gen.h"
#include "hphp/runtime/vm/jit/arg-group.h"
#include "hphp/runtime/vm/jit/code-gen-helpers.h"
#include "hphp/runtime/vm/jit/target-profile.h"
#include "hphp/runtime/vm/jit/vasm-x64.h"

namespace HPHP { namespace jit {
namespace NativeCalls { struct CallInfo; }
namespace arm { struct CodeGenerator; }
namespace x64 {

// Cache alignment is required for mutable instructions to make sure
// mutations don't "tear" on remote cpus.
constexpr size_t kCacheLineSize = 64;
constexpr size_t kCacheLineMask = kCacheLineSize - 1;

struct CodeGenerator {
  friend struct arm::CodeGenerator;

  CodeGenerator(CodegenState& state, Vout& main, Vout& cold)
    : m_state(state)
    , m_vmain(main)
    , m_vcold(cold)
  {}

  void cgInst(IRInstruction* inst);

private:
  Vloc srcLoc(const IRInstruction* inst, unsigned i) const;
  Vloc dstLoc(const IRInstruction* inst, unsigned i) const;
  ArgGroup argGroup(const IRInstruction* inst) const;

  // Autogenerate function declarations for each IR instruction in ir-opcode.h
#define O(name, dsts, srcs, flags) void cg##name(IRInstruction* inst);
  IR_OPCODES
#undef O

  void cgCallNative(Vout& v, IRInstruction* inst);

  CallDest callDest(Vreg reg0) const;
  CallDest callDest(Vreg reg0, Vreg reg1) const;
  CallDest callDest(const IRInstruction*) const;
  CallDest callDestTV(const IRInstruction*) const;
  CallDest callDestDbl(const IRInstruction*) const;
  template<class Arg>
  CppCall arrayCallIfLowMem(const IRInstruction* inst, Arg vtable) const;

  // Main call helper:
  void cgCallHelper(Vout& v, CppCall call, const CallDest& dstInfo,
                    SyncOptions sync, ArgGroup& args);
  void cgInterpOneCommon(IRInstruction* inst);

  enum class Width { Value, Full };
  void emitStore(Vptr dst, SSATmp* src, Vloc src_loc, Width);
  void emitStoreTypedValue(Vptr dst, SSATmp* src, Vloc src_loc);

  void emitLoad(SSATmp* dst, Vloc dstLoc, Vptr base);
  void emitLoadTypedValue(SSATmp* dst, Vloc dstLoc, Vptr ref);

  template <class JmpFn>
  void emitReffinessTest(IRInstruction* inst, Vreg sf, JmpFn doJcc);

  template<class Loc1, class Loc2, class JmpFn>
  void emitTypeTest(Type type, Loc1 typeSrc, Loc2 dataSrc, Vreg sf,
                    JmpFn doJcc);

  template<class DataLoc, class JmpFn>
  void emitSpecializedTypeTest(Type type, DataLoc data, Vreg sf, JmpFn doJcc);

  template<class Loc>
  void emitTypeCheck(Type type, Loc typeSrc,
                     Loc dataSrc, Block* taken);
  template<class Loc>
  void emitTypeGuard(const BCMarker& marker, Type type, Loc typeLoc,
                     Loc dataLoc);

  void cgIncRefWork(Type type, SSATmp* src, Vloc srcLoc);
  void cgDecRefWork(IRInstruction* inst, bool genZeroCheck);

  template<class Emit> void cgBinaryDblOp(IRInstruction*, Emit);
  template<class Op, class Opi> void cgShiftCommon(IRInstruction*);

  void emitVerifyCls(IRInstruction* inst);

  void emitGetCtxFwdCallWithThis(Vreg srcCtx, Vreg dstCtx, bool staticCallee);

  Vreg emitGetCtxFwdCallWithThisDyn(Vreg destCtxReg, Vreg thisReg,
                                    RDS::Handle ch);

  void cgJcc(IRInstruction* inst);          // helper
  void cgReqBindJcc(IRInstruction* inst);   // helper
  void cgExitJcc(IRInstruction* inst);      // helper
  void cgJccInt(IRInstruction* inst);         // helper
  void cgReqBindJccInt(IRInstruction* inst);  // helper
  void cgExitJccInt(IRInstruction* inst); // helper
  void emitCmpInt(IRInstruction* inst, ConditionCode cc);
  void emitCmpEqDbl(IRInstruction* inst, ComparisonPred pred);
  void emitCmpRelDbl(IRInstruction* inst, ConditionCode cc, bool flipOperands);
  void cgCmpHelper(IRInstruction* inst, ConditionCode cc,
                   int64_t (*str_cmp_str)(StringData*, StringData*),
                   int64_t (*str_cmp_int)(StringData*, int64_t),
                   int64_t (*str_cmp_obj)(StringData*, ObjectData*),
                   int64_t (*obj_cmp_obj)(ObjectData*, ObjectData*),
                   int64_t (*obj_cmp_int)(ObjectData*, int64_t),
                   int64_t (*arr_cmp_arr)(ArrayData*, ArrayData*));

  void emitReqBindJcc(Vout& v, ConditionCode cc, Vreg sf,
                      const ReqBindJccData*);

  Vreg emitCompare(Vout& v, IRInstruction* inst);
  Vreg emitCompareInt(Vout& v, IRInstruction* inst);
  Vreg emitTestZero(Vout& v, SSATmp* src, Vloc srcLoc);
  template<class Inst>
  bool emitIncDec(Vout& v, Vloc dst, SSATmp* src0, Vloc loc0,
                  SSATmp* src1, Vloc loc1, Vreg& sf);
  Vreg emitAddInt(Vout& v, IRInstruction* inst);
  Vreg emitSubInt(Vout& v, IRInstruction* inst);
  Vreg emitMulInt(Vout& v, IRInstruction* inst);

private:
  Vreg selectScratchReg(IRInstruction* inst);
  RegSet findFreeRegs(IRInstruction* inst);
  void emitSetCc(IRInstruction*, ConditionCode cc, Vreg sf);
  template<class JmpFn>
  void emitIsTypeTest(IRInstruction* inst, Vreg sf, JmpFn doJcc);
  void cgIsTypeCommon(IRInstruction* inst, bool negate);
  void cgIsTypeMemCommon(IRInstruction*, bool negate);
  Vreg emitInstanceBitmaskCheck(Vout& v, IRInstruction* inst);
  void emitInitObjProps(const IRInstruction* inst, Vreg dstReg,
                        const Class* cls, size_t nProps);

  bool decRefDestroyIsUnlikely(const IRInstruction* inst,
                               OptDecRefProfile& profile, Type type);
  template <typename F>
  void cgCheckStaticBitAndDecRef(Vout& v, const IRInstruction* inst,
                                 Vlabel done, Type type,
                                 Vreg dataReg, F destroyImpl);
  void cgCheckStaticBitAndDecRef(Vout& v, const IRInstruction* inst,
                                 Vlabel done, Type type,
                                 Vreg dataReg);
  void cgCheckRefCountedType(Vreg typeReg, Vlabel done);
  void cgCheckRefCountedType(Vreg baseReg, int64_t offset, Vlabel done);
  void cgDecRefStaticType(Vout&, const IRInstruction* inst, Type type,
                          Vreg dataReg, bool genZeroCheck);
  void cgDecRefDynamicType(const IRInstruction* inst, Vreg typeReg,
                           Vreg dataReg, bool genZeroCheck);
  void cgDecRefDynamicTypeMem(const IRInstruction* inst, Vreg baseReg,
                              int64_t offset);
  void cgDecRefMem(const IRInstruction* inst, Type type, Vreg baseReg,
                   int64_t offset);

  void cgIterNextCommon(IRInstruction* inst);
  void cgIterInitCommon(IRInstruction* inst);
  void cgMIterNextCommon(IRInstruction* inst);
  void cgMIterInitCommon(IRInstruction* inst);
  Vreg cgLdFuncCachedCommon(IRInstruction* inst, Vreg dst);
  void cgLookupCnsCommon(IRInstruction* inst);
  RDS::Handle cgLdClsCachedCommon(Vout& v, IRInstruction* inst, Vreg dst,
                                  Vreg sf);
  void cgDefineModifiedStkPtr(IRInstruction*);
  void cgPropImpl(IRInstruction*);
  void cgVGetPropImpl(IRInstruction*);
  void cgBindPropImpl(IRInstruction*);
  void cgSetPropImpl(IRInstruction*);
  void cgSetOpPropImpl(IRInstruction*);
  void cgIncDecPropImpl(IRInstruction*);
  void cgIssetEmptyPropImpl(IRInstruction*);
  void cgElemImpl(IRInstruction*);
  void cgElemArrayImpl(IRInstruction*);
  void cgVGetElemImpl(IRInstruction*);
  void cgArraySetImpl(IRInstruction*);
  void cgSetElemImpl(IRInstruction*);
  void cgUnsetElemImpl(IRInstruction*);
  void cgIssetEmptyElemImpl(IRInstruction*);

  Vlabel label(Block*);
  void emitFwdJcc(Vout& v, ConditionCode cc, Vreg sf, Block* target);

  static const Func* getFunc(const BCMarker& marker) {
    return marker.func();
  };
  static const Class* getClass(const BCMarker& marker) {
    return getFunc(marker)->cls();
  }
  static const Unit* getUnit(const BCMarker& marker) {
    return getFunc(marker)->unit();
  }
  static bool resumed(const BCMarker& marker) {
    return marker.resumed();
  };

  Fixup makeFixup(const BCMarker& marker,
                  SyncOptions sync = SyncOptions::kSyncPoint);
  int iterOffset(const BCMarker& marker, uint32_t id);

  void emitConvBoolOrIntToDbl(IRInstruction* inst);
  void cgLdClsMethodCacheCommon(IRInstruction* inst, Offset offset);
  void emitLdRaw(IRInstruction* inst, size_t extraOff);
  void emitStRaw(IRInstruction* inst, size_t offset, int size);
  void resumableStResumeImpl(IRInstruction*, ptrdiff_t, ptrdiff_t);

  void emitStoreTypedValue(Vout& v, Vreg base, ptrdiff_t offset,
    Vloc src, Type srcType);

  /*
   * Execute the code emitted by 'taken' only if the given condition code is
   * true.
   */
  template <class Block>
  void ifBlock(Vout& v, Vout& vcold, ConditionCode cc, Vreg sf, Block taken,
             bool unlikely = false);

  /*
   * Generate an if-block that branches around some unlikely code, handling
   * the cases when a == acold and a != acold.  cc is the branch condition
   * to run the unlikely block.
   *
   * Passes the proper assembler to use to the unlikely function.
   */
  template <class Then>
  void unlikelyIfBlock(Vout& v, Vout& vcold, ConditionCode cc, Vreg sf,
                       Then then);

  // Generate an if-then-else block
  template <class Then, class Else>
  void ifThenElse(Vout& v, ConditionCode cc, Vreg sf, Then thenBlock,
                  Else elseBlock);

  // Generate an if-then-else block into m_as.
  template <class Then, class Else>
  void ifThenElse(Vout& v, Vout& vcold, ConditionCode cc, Vreg sf,
                  Then thenBlock, Else elseBlock, bool unlikely = false);

  /*
   * Same as ifThenElse except the first block is off in acold
   */
  template <class Then, class Else>
  void unlikelyIfThenElse(Vout& v, Vout& vcold, ConditionCode cc, Vreg sf,
                          Then unlikelyBlock, Else elseBlock);

  // This is for printing partially-generated traces when debugging
  void print() const;

  Vout& vmain() { return m_vmain; }
  Vout& vcold() { return m_vcold; }

private:
  CodegenState&       m_state;
  Vout&               m_vmain;
  Vout&               m_vcold;
};

// Helpers to compute a reference to a TypedValue type and data
inline Vptr refTVType(Vreg reg) {
  return reg[TVOFF(m_type)];
}

inline Vptr refTVData(Vreg reg) {
  return reg[TVOFF(m_data)];
}

inline Vptr refTVType(Vptr ref) {
  return ref + TVOFF(m_type);
}

inline Vptr refTVData(Vptr ref) {
  return ref + TVOFF(m_data);
}

}}}

#endif