blob: 39348ed5ee1662daa6c27d3f16a946f77aefe6b0 [file] [log] [blame]
// Copyright 2011 Google Inc. All Rights Reserved.
#include "dex_instruction.h"
namespace art {
const char* const Instruction::kInstructionNames[] = {
#define INSTRUCTION_NAME(o, c, pname, f, r, i, a, v) pname,
#include "dex_instruction_list.h"
DEX_INSTRUCTION_LIST(INSTRUCTION_NAME)
#undef DEX_INSTRUCTION_LIST
#undef INSTRUCTION_NAME
};
Instruction::InstructionFormat const Instruction::kInstructionFormats[] = {
#define INSTRUCTION_FORMAT(o, c, p, format, r, i, a, v) format,
#include "dex_instruction_list.h"
DEX_INSTRUCTION_LIST(INSTRUCTION_FORMAT)
#undef DEX_INSTRUCTION_LIST
#undef INSTRUCTION_FORMAT
};
int const Instruction::kInstructionFlags[] = {
#define INSTRUCTION_FLAGS(o, c, p, f, r, i, flags, v) flags,
#include "dex_instruction_list.h"
DEX_INSTRUCTION_LIST(INSTRUCTION_FLAGS)
#undef DEX_INSTRUCTION_LIST
#undef INSTRUCTION_FLAGS
};
int const Instruction::kInstructionVerifyFlags[] = {
#define INSTRUCTION_VERIFY_FLAGS(o, c, p, f, r, i, a, vflags) vflags,
#include "dex_instruction_list.h"
DEX_INSTRUCTION_LIST(INSTRUCTION_VERIFY_FLAGS)
#undef DEX_INSTRUCTION_LIST
#undef INSTRUCTION_VERIFY_FLAGS
};
/*
* Handy macros for helping decode instructions.
*/
#define FETCH(_offset) (insns[(_offset)])
#define FETCH_u4(_offset) (fetch_u4_impl((_offset), insns))
#define INST_A(_insn) (((uint16_t)(_insn) >> 8) & 0x0f)
#define INST_B(_insn) ((uint16_t)(_insn) >> 12)
#define INST_AA(_insn) ((_insn) >> 8)
/* Helper for FETCH_u4, above. */
static inline uint32_t fetch_u4_impl(uint32_t offset, const uint16_t* insns) {
return insns[offset] | ((uint32_t) insns[offset+1] << 16);
}
void Instruction::Decode(uint32_t &vA, uint32_t &vB, uint64_t &vB_wide, uint32_t &vC, uint32_t arg[]) const {
const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
uint16_t insn = *insns;
int opcode = insn & 0xFF;
switch (Format()) {
case k10x: // op
/* nothing to do; copy the AA bits out for the verifier */
vA = INST_AA(insn);
break;
case k12x: // op vA, vB
vA = INST_A(insn);
vB = INST_B(insn);
break;
case k11n: // op vA, #+B
vA = INST_A(insn);
vB = (int32_t) (INST_B(insn) << 28) >> 28; // sign extend 4-bit value
break;
case k11x: // op vAA
vA = INST_AA(insn);
break;
case k10t: // op +AA
vA = (int8_t) INST_AA(insn); // sign-extend 8-bit value
break;
case k20t: // op +AAAA
vA = (int16_t) FETCH(1); // sign-extend 16-bit value
break;
case k21c: // op vAA, thing@BBBB
case k22x: // op vAA, vBBBB
vA = INST_AA(insn);
vB = FETCH(1);
break;
case k21s: // op vAA, #+BBBB
case k21t: // op vAA, +BBBB
vA = INST_AA(insn);
vB = (int16_t) FETCH(1); // sign-extend 16-bit value
break;
case k21h: // op vAA, #+BBBB0000[00000000]
vA = INST_AA(insn);
/*
* The value should be treated as right-zero-extended, but we don't
* actually do that here. Among other things, we don't know if it's
* the top bits of a 32- or 64-bit value.
*/
vB = FETCH(1);
break;
case k23x: // op vAA, vBB, vCC
vA = INST_AA(insn);
vB = FETCH(1) & 0xff;
vC = FETCH(1) >> 8;
break;
case k22b: // op vAA, vBB, #+CC
vA = INST_AA(insn);
vB = FETCH(1) & 0xff;
vC = (int8_t) (FETCH(1) >> 8); // sign-extend 8-bit value
break;
case k22s: // op vA, vB, #+CCCC
case k22t: // op vA, vB, +CCCC
vA = INST_A(insn);
vB = INST_B(insn);
vC = (int16_t) FETCH(1); // sign-extend 16-bit value
break;
case k22c: // op vA, vB, thing@CCCC
vA = INST_A(insn);
vB = INST_B(insn);
vC = FETCH(1);
break;
case k30t: // op +AAAAAAAA
vA = FETCH_u4(1); // signed 32-bit value
break;
case k31t: // op vAA, +BBBBBBBB
case k31c: // op vAA, string@BBBBBBBB
vA = INST_AA(insn);
vB = FETCH_u4(1); // 32-bit value
break;
case k32x: // op vAAAA, vBBBB
vA = FETCH(1);
vB = FETCH(2);
break;
case k31i: // op vAA, #+BBBBBBBB
vA = INST_AA(insn);
vB = FETCH_u4(1); // signed 32-bit value
break;
case k35c: // op {vC, vD, vE, vF, vG}, thing@BBBB
{
/*
* Note that the fields mentioned in the spec don't appear in
* their "usual" positions here compared to most formats. This
* was done so that the field names for the argument count and
* reference index match between this format and the corresponding
* range formats (3rc and friends).
*
* Bottom line: The argument count is always in vA, and the
* method constant (or equivalent) is always in vB.
*/
uint16_t regList;
int count;
vA = INST_B(insn); // This is labeled A in the spec.
vB = FETCH(1);
regList = FETCH(2);
count = vA;
/*
* Copy the argument registers into the arg[] array, and
* also copy the first argument (if any) into vC. (The
* DecodedInstruction structure doesn't have separate
* fields for {vD, vE, vF, vG}, so there's no need to make
* copies of those.) Note that cases 5..2 fall through.
*/
switch (count) {
case 5: arg[4] = INST_A(insn);
case 4: arg[3] = (regList >> 12) & 0x0f;
case 3: arg[2] = (regList >> 8) & 0x0f;
case 2: arg[1] = (regList >> 4) & 0x0f;
case 1: vC = arg[0] = regList & 0x0f; break;
case 0: break; // Valid, but no need to do anything.
default:
LOG(ERROR) << "Invalid arg count in 35c (" << count << ")";
return;
}
}
break;
case k3rc: // op {vCCCC .. v(CCCC+AA-1)}, meth@BBBB
vA = INST_AA(insn);
vB = FETCH(1);
vC = FETCH(2);
break;
case k51l: // op vAA, #+BBBBBBBBBBBBBBBB
vA = INST_AA(insn);
vB_wide = FETCH_u4(1) | ((uint64_t) FETCH_u4(3) << 32);
break;
default:
LOG(ERROR) << "Can't decode unexpected format " << (int) Format() << " (op=" << opcode << ")";
return;
}
}
size_t Instruction::Size() const {
const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
if (*insns == kPackedSwitchSignature) {
return (4 + insns[1] * 2);
} else if (*insns == kSparseSwitchSignature) {
return (2 + insns[1] * 4);
} else if (*insns == kArrayDataSignature) {
uint16_t element_size = insns[1];
uint32_t length = insns[2] | (((uint32_t)insns[3]) << 16);
// The plus 1 is to round up for odd size and width.
return (4 + (element_size * length + 1) / 2);
} else {
switch (Format()) {
case k10x:
case k12x:
case k11n:
case k11x:
case k10t:
return 1;
case k20t:
case k22x:
case k21t:
case k21s:
case k21h:
case k21c:
case k23x:
case k22b:
case k22t:
case k22s:
case k22c:
return 2;
case k32x:
case k30t:
case k31t:
case k31i:
case k31c:
case k35c:
case k3rc:
return 3;
case k51l:
return 5;
default:
LOG(FATAL) << "Unreachable";
}
}
return 0;
}
Instruction::Code Instruction::Opcode() const {
const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
int opcode = *insns & 0xFF;
return static_cast<Code>(opcode);
}
const Instruction* Instruction::Next() const {
size_t current_size = Size() * sizeof(uint16_t);
const uint8_t* ptr = reinterpret_cast<const uint8_t*>(this);
return reinterpret_cast<const Instruction*>(ptr + current_size);
}
} // namespace art