smi_prims.cpp

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/* Copyright 1994, 1995 LongView Technologies L.L.C. $Revision: 1.15 $ */
/* Copyright (c) 2006, Sun Microsystems, Inc.
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# include "incls/_precompiled.incl"
# include "incls/_smi_prims.cpp.incl"

TRACE_FUNC(TraceSmiPrims, "smi")

int smiOopPrimitives::number_of_calls;

# define ASSERT_RECEIVER assert(receiver->is_smi(), "receiver must be smi")

# define SMI_RELATIONAL_OP(op)                                     \
  if (!argument->is_smi())                                         \
    return markSymbol(vmSymbols::first_argument_has_wrong_type()); \
  int a = (int) receiver;                                          \
  int b = (int) argument;                                          \
  return a op b ? trueObj : falseObj

PRIM_DECL_2(smiOopPrimitives::lessThan, oop receiver, oop argument) {
  PROLOGUE_2("lessThan", receiver, argument);
  ASSERT_RECEIVER;
  SMI_RELATIONAL_OP(<);
}

PRIM_DECL_2(smiOopPrimitives::greaterThan, oop receiver, oop argument){
  PROLOGUE_2("greaterThan", receiver, argument);
  ASSERT_RECEIVER;
  SMI_RELATIONAL_OP(>);
}

PRIM_DECL_2(smiOopPrimitives::lessThanOrEqual, oop receiver, oop argument) {
  PROLOGUE_2("lessThanOrEqual", receiver, argument);
  ASSERT_RECEIVER;
  SMI_RELATIONAL_OP(<=);
}

PRIM_DECL_2(smiOopPrimitives::greaterThanOrEqual, oop receiver, oop argument) {
  PROLOGUE_2("greaterThanOrEqual", receiver, argument);
  ASSERT_RECEIVER;
  SMI_RELATIONAL_OP(>=);
}

PRIM_DECL_2(smiOopPrimitives::equal, oop receiver, oop argument) {
  PROLOGUE_2("equal", receiver, argument);
  ASSERT_RECEIVER;
  SMI_RELATIONAL_OP(==);
}

PRIM_DECL_2(smiOopPrimitives::notEqual, oop receiver, oop argument) {
  PROLOGUE_2("notEqual", receiver, argument);
  ASSERT_RECEIVER;
  SMI_RELATIONAL_OP(!=);
}

PRIM_DECL_2(smiOopPrimitives::bitAnd, oop receiver, oop argument) {
  PROLOGUE_2("bitAnd", receiver, argument);
  ASSERT_RECEIVER;
  if (!argument->is_smi())
    return markSymbol(vmSymbols::first_argument_has_wrong_type());
  return smiOop(int(receiver) & int(argument));  
}

PRIM_DECL_2(smiOopPrimitives::bitOr, oop receiver, oop argument) {
  PROLOGUE_2("bitOr", receiver, argument);
  ASSERT_RECEIVER;
  if (!argument->is_smi())
    return markSymbol(vmSymbols::first_argument_has_wrong_type());
  return smiOop(int(receiver) | int(argument));  
}

PRIM_DECL_2(smiOopPrimitives::bitXor, oop receiver, oop argument) {
  PROLOGUE_2("bitXor", receiver, argument);
  ASSERT_RECEIVER;
  if (!argument->is_smi())
    return markSymbol(vmSymbols::first_argument_has_wrong_type());
  return smiOop(int(receiver) ^ int(argument));  
}

PRIM_DECL_2(smiOopPrimitives::bitShift, oop receiver, oop argument) {
  PROLOGUE_2("bitShift", receiver, argument);
  ASSERT_RECEIVER;
  if (!argument->is_smi())
    return markSymbol(vmSymbols::first_argument_has_wrong_type());
  assert(Int_Tag == 0, "check this code");
  const int bitsPerWord = oopSize*8;
  const int maxShiftCnt = bitsPerWord - Tag_Size - 1;
  int n = smiOop(argument)->value();
  if (n > 0) {
    // arithmetic shift left
    if (n < maxShiftCnt) {
      // 0 < n < maxShiftCnt < bitsPerWord      // |<- n ->|<- 1 ->|<- 32-(n+1) ->|
      int mask1 =  1 << (bitsPerWord - (n+1));  // |00...00|   1   |00..........00|
      int mask2 = -1 << (bitsPerWord - n);      // |11...11|   0   |00..........00|
      if (((int(receiver) + mask1) & mask2) == 0) {
        // i.e., the bit at position (32-(n+1)) is the same as the upper n bits, thus
        // after shifting out the upper n bits the sign hasn't changed -> no overflow
        return smiOop(int(receiver) << n);
      }
    }
    return vmSymbols::smi_overflow();
  } else {
    // arithmetic shift right
    if (n < -maxShiftCnt) n = -maxShiftCnt;
    return smiOop((int(receiver) >> -n) & (-1 << Tag_Size));
  }
}

PRIM_DECL_2(smiOopPrimitives::rawBitShift, oop receiver, oop argument) {
  PROLOGUE_2("rawBitShift", receiver, argument);
  ASSERT_RECEIVER;
  if (!argument->is_smi())
    return markSymbol(vmSymbols::first_argument_has_wrong_type());
  assert(Int_Tag == 0, "check this code");
  const int bitsPerWord = oopSize*8;
  int n = smiOop(argument)->value();
  if (n >= 0) {
    // logical shift right
    return smiOop((unsigned int)receiver << (n % bitsPerWord));
  } else {
    // logical shift left
    return smiOop(((unsigned int)receiver >> ((-n) % bitsPerWord)) & (-1 << Tag_Size));
  }
}

PRIM_DECL_1(smiOopPrimitives::asObject, oop receiver) {
  PROLOGUE_1("asObject", receiver);
  ASSERT_RECEIVER;
  int id = smiOop(receiver)->value();
  if (objectIDTable::is_index_ok(id))
     return objectIDTable::at(id);
  return markSymbol(vmSymbols::index_not_valid());
}

PRIM_DECL_1(smiOopPrimitives::printCharacter, oop receiver) {
  PROLOGUE_1("printCharacter", receiver);
  ASSERT_RECEIVER;
  lprintf("%c", smiOop(receiver)->value());
  return receiver;
}

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