/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package jdk.tools.jaotc.amd64;
import jdk.tools.jaotc.InstructionDecoder;
import jdk.vm.ci.code.TargetDescription;
public final class AMD64InstructionDecoder extends InstructionDecoder {
private boolean targetIs64Bit;
private int currentEndOfInstruction;
private static class Prefix {
// segment overrides
static final int CSSegment = 0x2e;
static final int SSSegment = 0x36;
static final int DSSegment = 0x3e;
static final int ESSegment = 0x26;
static final int FSSegment = 0x64;
static final int GSSegment = 0x65;
static final int REX = 0x40;
static final int REXB = 0x41;
static final int REXX = 0x42;
static final int REXXB = 0x43;
static final int REXR = 0x44;
static final int REXRB = 0x45;
static final int REXRX = 0x46;
static final int REXRXB = 0x47;
static final int REXW = 0x48;
static final int REXWB = 0x49;
static final int REXWX = 0x4A;
static final int REXWXB = 0x4B;
static final int REXWR = 0x4C;
static final int REXWRB = 0x4D;
static final int REXWRX = 0x4E;
static final int REXWRXB = 0x4F;
static final int VEX_3BYTES = 0xC4;
static final int VEX_2BYTES = 0xC5;
}
@SuppressWarnings("unused")
private static class VexPrefix {
static final int VEX_R = 0x80;
static final int VEX_W = 0x80;
}
@SuppressWarnings("unused")
private static class VexOpcode {
static final int VEX_OPCODE_NONE = 0x0;
static final int VEX_OPCODE_0F = 0x1;
static final int VEX_OPCODE_0F_38 = 0x2;
static final int VEX_OPCODE_0F_3A = 0x3;
static final int VEX_OPCODE_MASK = 0x1F;
}
public AMD64InstructionDecoder(TargetDescription target) {
this.targetIs64Bit = target.wordSize == 8;
}
@Override
public int currentEndOfInstruction() {
return currentEndOfInstruction;
}
@Override
@SuppressWarnings("fallthrough")
public void decodePosition(final byte[] code, int pcOffset) {
assert pcOffset >= 0 && pcOffset < code.length;
// Decode the given instruction, and return the Pointer of
// an embedded 32-bit operand word.
// If "which" is WhichOperand.disp32operand, selects the displacement portion
// of an effective Pointer specifier.
// If "which" is imm64Operand, selects the trailing immediate constant.
// If "which" is WhichOperand.call32operand, selects the displacement of a call or jump.
// Caller is responsible for ensuring that there is such an operand,
// and that it is 32/64 bits wide.
// If "which" is endPcOperand, find the end of the instruction.
int ip = pcOffset;
boolean is64bit = false;
boolean hasDisp32 = false;
int tailSize = 0; // other random bytes (#32, #16, etc.) at end of insn
boolean againAfterPrefix = true;
while (againAfterPrefix) {
againAfterPrefix = false;
switch (0xFF & code[ip++]) {
// These convenience macros generate groups of "case" labels for the switch.
case Prefix.CSSegment:
case Prefix.SSSegment:
case Prefix.DSSegment:
case Prefix.ESSegment:
case Prefix.FSSegment:
case Prefix.GSSegment:
// Seems dubious
assert !targetIs64Bit : "shouldn't have that prefix";
assert ip == pcOffset + 1 : "only one prefix allowed";
againAfterPrefix = true;
break;
case 0x67:
case Prefix.REX:
case Prefix.REXB:
case Prefix.REXX:
case Prefix.REXXB:
case Prefix.REXR:
case Prefix.REXRB:
case Prefix.REXRX:
case Prefix.REXRXB:
assert targetIs64Bit : "64bit prefixes";
againAfterPrefix = true;
break;
case Prefix.REXW:
case Prefix.REXWB:
case Prefix.REXWX:
case Prefix.REXWXB:
case Prefix.REXWR:
case Prefix.REXWRB:
case Prefix.REXWRX:
case Prefix.REXWRXB:
assert targetIs64Bit : "64bit prefixes";
is64bit = true;
againAfterPrefix = true;
break;
case 0xFF: // pushq a; decl a; incl a; call a; jmp a
case 0x88: // movb a, r
case 0x89: // movl a, r
case 0x8A: // movb r, a
case 0x8B: // movl r, a
case 0x8F: // popl a
hasDisp32 = true;
break;
case 0x68: // pushq #32
currentEndOfInstruction = ip + 4;
return; // not produced by emitOperand
case 0x66: // movw ... (size prefix)
boolean againAfterSizePrefix2 = true;
while (againAfterSizePrefix2) {
againAfterSizePrefix2 = false;
switch (0xFF & code[ip++]) {
case Prefix.REX:
case Prefix.REXB:
case Prefix.REXX:
case Prefix.REXXB:
case Prefix.REXR:
case Prefix.REXRB:
case Prefix.REXRX:
case Prefix.REXRXB:
case Prefix.REXW:
case Prefix.REXWB:
case Prefix.REXWX:
case Prefix.REXWXB:
case Prefix.REXWR:
case Prefix.REXWRB:
case Prefix.REXWRX:
case Prefix.REXWRXB:
assert targetIs64Bit : "64bit prefix found";
againAfterSizePrefix2 = true;
break;
case 0x8B: // movw r, a
case 0x89: // movw a, r
hasDisp32 = true;
break;
case 0xC7: // movw a, #16
hasDisp32 = true;
tailSize = 2; // the imm16
break;
case 0x0F: // several SSE/SSE2 variants
ip--; // reparse the 0x0F
againAfterPrefix = true;
break;
default:
throw new InternalError("should not reach here");
}
}
break;
case 0xB8: // movl/q r, #32/#64(oop?)
case 0xB9:
case 0xBA:
case 0xBB:
case 0xBC:
case 0xBD:
case 0xBE:
case 0xBF:
currentEndOfInstruction = ip + (is64bit ? 8 : 4);
return;
case 0x69: // imul r, a, #32
case 0xC7: // movl a, #32(oop?)
tailSize = 4;
hasDisp32 = true; // has both kinds of operands!
break;
case 0x0F: // movx..., etc.
switch (0xFF & code[ip++]) {
case 0x3A: // pcmpestri
ip++; // skip opcode
tailSize = 1;
hasDisp32 = true; // has both kinds of operands!
break;
case 0x38: // ptest, pmovzxbw
ip++; // skip opcode
hasDisp32 = true; // has both kinds of operands!
break;
case 0x70: // pshufd r, r/a, #8
hasDisp32 = true; // has both kinds of operands!
tailSize = 1;
break;
case 0x73: // psrldq r, #8
tailSize = 1;
break;
case 0x12: // movlps
case 0x28: // movaps
case 0x2E: // ucomiss
case 0x2F: // comiss
case 0x54: // andps
case 0x55: // andnps
case 0x56: // orps
case 0x57: // xorps
case 0x58: // addpd
case 0x59: // mulpd
case 0x6E: // movd
case 0x7E: // movd
case 0xAE: // ldmxcsr, stmxcsr, fxrstor, fxsave, clflush
case 0xFE: // paddd
// 64bit side says it these have both operands but that doesn't
// appear to be true
hasDisp32 = true;
break;
case 0xAD: // shrd r, a, %cl
case 0xAF: // imul r, a
case 0xBE: // movsbl r, a (movsxb)
case 0xBF: // movswl r, a (movsxw)
case 0xB6: // movzbl r, a (movzxb)
case 0xB7: // movzwl r, a (movzxw)
case 0x40: // cmovl cc, r, a
case 0x41:
case 0x42:
case 0x43:
case 0x44:
case 0x45:
case 0x46:
case 0x47:
case 0x48:
case 0x49:
case 0x4A:
case 0x4B:
case 0x4C:
case 0x4D:
case 0x4E:
case 0x4F:
case 0xB0: // cmpxchgb
case 0xB1: // cmpxchg
case 0xC1: // xaddl
case 0xC7: // cmpxchg8
case 0x90: // setcc a
case 0x91:
case 0x92:
case 0x93:
case 0x94:
case 0x95:
case 0x96:
case 0x97:
case 0x98:
case 0x99:
case 0x9A:
case 0x9B:
case 0x9C:
case 0x9D:
case 0x9E:
case 0x9F:
hasDisp32 = true;
// fall out of the switch to decode the Pointer
break;
case 0xC4: // pinsrw r, a, #8
hasDisp32 = true;
tailSize = 1; // the imm8
break;
case 0xC5: // pextrw r, r, #8
tailSize = 1; // the imm8
break;
case 0xAC: // shrd r, a, #8
hasDisp32 = true;
tailSize = 1; // the imm8
break;
case 0x80: // jcc rdisp32
case 0x81:
case 0x82:
case 0x83:
case 0x84:
case 0x85:
case 0x86:
case 0x87:
case 0x88:
case 0x89:
case 0x8A:
case 0x8B:
case 0x8C:
case 0x8D:
case 0x8E:
case 0x8F:
currentEndOfInstruction = ip + 4;
return;
default:
throw new InternalError("should not reach here");
}
break;
case 0x81: // addl a, #32; addl r, #32
// also: orl, adcl, sbbl, andl, subl, xorl, cmpl
// on 32bit in the case of cmpl, the imm might be an oop
tailSize = 4;
hasDisp32 = true; // has both kinds of operands!
break;
case 0x83: // addl a, #8; addl r, #8
// also: orl, adcl, sbbl, andl, subl, xorl, cmpl
hasDisp32 = true; // has both kinds of operands!
tailSize = 1;
break;
case 0x9B:
switch (0xFF & code[ip++]) {
case 0xD9: // fnstcw a
hasDisp32 = true;
break;
default:
throw new InternalError("should not reach here");
}
break;
case 0x00: // addb a, r; addl a, r; addb r, a; addl r, a
case 0x01:
case 0x02:
case 0x03:
case 0x10: // adc...
case 0x11:
case 0x12:
case 0x13:
case 0x20: // and...
case 0x21:
case 0x22:
case 0x23:
case 0x30: // xor...
case 0x31:
case 0x32:
case 0x33:
case 0x08: // or...
case 0x09:
case 0x0a:
case 0x0b:
case 0x18: // sbb...
case 0x19:
case 0x1a:
case 0x1b:
case 0x28: // sub...
case 0x29:
case 0x2a:
case 0x2b:
case 0xF7: // mull a
case 0x8D: // lea r, a
case 0x87: // xchg r, a
case 0x38: // cmp...
case 0x39:
case 0x3a:
case 0x3b:
case 0x85: // test r, a
hasDisp32 = true; // has both kinds of operands!
break;
case 0xC1: // sal a, #8; sar a, #8; shl a, #8; shr a, #8
case 0xC6: // movb a, #8
case 0x80: // cmpb a, #8
case 0x6B: // imul r, a, #8
hasDisp32 = true; // has both kinds of operands!
tailSize = 1; // the imm8
break;
case Prefix.VEX_3BYTES:
case Prefix.VEX_2BYTES:
assert ip == pcOffset + 1 : "no prefixes allowed";
int vexOpcode;
// First byte
if ((code[pcOffset] & 0xFF) == Prefix.VEX_3BYTES) {
vexOpcode = VexOpcode.VEX_OPCODE_MASK & code[ip];
ip++; // third byte
is64bit = ((VexPrefix.VEX_W & code[ip]) == VexPrefix.VEX_W);
} else {
vexOpcode = VexOpcode.VEX_OPCODE_0F;
}
ip++; // opcode
// To find the end of instruction (which == end_pc_operand).
switch (vexOpcode) {
case VexOpcode.VEX_OPCODE_0F:
switch (0xFF & code[ip]) {
case 0x70: // pshufd r, r/a, #8
case 0x71: // ps[rl|ra|ll]w r, #8
case 0x72: // ps[rl|ra|ll]d r, #8
case 0x73: // ps[rl|ra|ll]q r, #8
case 0xC2: // cmp[ps|pd|ss|sd] r, r, r/a, #8
case 0xC4: // pinsrw r, r, r/a, #8
case 0xC5: // pextrw r/a, r, #8
case 0xC6: // shufp[s|d] r, r, r/a, #8
tailSize = 1; // the imm8
break;
default:
break; // no imm8
}
break;
case VexOpcode.VEX_OPCODE_0F_3A:
tailSize = 1;
break;
default:
throw new InternalError("should not reach here");
}
ip++; // skip opcode
hasDisp32 = true;
break;
case 0xE8: // call rdisp32
case 0xE9: // jmp rdisp32
currentEndOfInstruction = ip + 4;
return;
case 0xD1: // sal a, 1; sar a, 1; shl a, 1; shr a, 1
case 0xD3: // sal a, %cl; sar a, %cl; shl a, %cl; shr a, %cl
case 0xD9: // fldS a; fstS a; fstpS a; fldcw a
case 0xDD: // fldD a; fstD a; fstpD a
case 0xDB: // fildS a; fistpS a; fldX a; fstpX a
case 0xDF: // fildD a; fistpD a
case 0xD8: // faddS a; fsubrS a; fmulS a; fdivrS a; fcompS a
case 0xDC: // faddD a; fsubrD a; fmulD a; fdivrD a; fcompD a
case 0xDE: // faddpD a; fsubrpD a; fmulpD a; fdivrpD a; fcomppD a
hasDisp32 = true;
break;
case 0xF0: // Lock
againAfterPrefix = true;
break;
case 0xF3: // For SSE
case 0xF2: // For SSE2
switch (0xFF & code[ip++]) {
case Prefix.REX:
case Prefix.REXB:
case Prefix.REXX:
case Prefix.REXXB:
case Prefix.REXR:
case Prefix.REXRB:
case Prefix.REXRX:
case Prefix.REXRXB:
case Prefix.REXW:
case Prefix.REXWB:
case Prefix.REXWX:
case Prefix.REXWXB:
case Prefix.REXWR:
case Prefix.REXWRB:
case Prefix.REXWRX:
case Prefix.REXWRXB:
assert targetIs64Bit : "found 64bit prefix";
ip++;
ip++;
break;
default:
ip++;
}
hasDisp32 = true; // has both kinds of operands!
break;
default:
throw new InternalError("should not reach here");
}
}
assert hasDisp32 : "(tw) not sure if this holds: instruction has no disp32 field";
// parse the output of emitOperand
int op2 = 0xFF & code[ip++];
int base = op2 & 0x07;
int op3 = -1;
int b100 = 4;
int b101 = 5;
if (base == b100 && (op2 >> 6) != 3) {
op3 = 0xFF & code[ip++];
base = op3 & 0x07; // refetch the base
}
// now ip points at the disp (if any)
switch (op2 >> 6) {
case 0:
// [00 reg 100][ss index base]
// [00 reg 100][00 100 esp]
// [00 reg base]
// [00 reg 100][ss index 101][disp32]
// [00 reg 101] [disp32]
if (base == b101) {
ip += 4; // skip the disp32
}
break;
case 1:
// [01 reg 100][ss index base][disp8]
// [01 reg 100][00 100 esp][disp8]
// [01 reg base] [disp8]
ip += 1; // skip the disp8
break;
case 2:
// [10 reg 100][ss index base][disp32]
// [10 reg 100][00 100 esp][disp32]
// [10 reg base] [disp32]
ip += 4; // skip the disp32
break;
case 3:
// [11 reg base] (not a memory addressing mode)
break;
}
currentEndOfInstruction = ip + tailSize;
}
}