/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.vm.x86.compiler.l1a;
import org.jnode.assembler.x86.X86Assembler;
import org.jnode.assembler.x86.X86Register;
import org.jnode.assembler.x86.X86Register.GPR;
import org.jnode.assembler.x86.X86Register.GPR64;
import org.jnode.vm.JvmType;
import org.jnode.vm.compiler.IllegalModeException;
/**
* @author Ewout Prangsma (epr@users.sourceforge.net)
*/
final class L1AHelper {
static void assertCondition(boolean cond, String message) {
if (!cond)
throw new Error("assert failed: " + message);
}
static void assertCondition(boolean cond, String message, Object param) {
if (!cond) {
throw new Error("assert failed: " + message + param);
}
}
/**
* Gets the 64-bit equivalent of the given 32-bit register.
*
* @param eContext
* @param src
* @return the 64-bit register.
*/
static GPR64 get64BitReg(EmitterContext eContext, GPR src) {
return (GPR64) eContext.getGPRPool().getRegisterInSameGroup(src, JvmType.LONG);
}
/**
* Release a register.
*
* @param eContext
* @param reg
*/
static void releaseRegister(EmitterContext eContext, X86Register reg) {
final X86RegisterPool pool = eContext.getGPRPool();
pool.release(reg);
}
/**
* Request two register for a 8-byte item.
*
* @param eContext
* @param jvmType
* @return
*/
static DoubleWordItem requestDoubleWordRegisters(
EmitterContext eContext, int jvmType) {
final X86RegisterPool pool = eContext.getGPRPool();
final X86Assembler os = eContext.getStream();
final ItemFactory ifac = eContext.getItemFactory();
final DoubleWordItem result;
if (os.isCode32()) {
final X86Register.GPR lsb = (X86Register.GPR) requestRegister(eContext, JvmType.INT, false);
final X86Register.GPR msb = (X86Register.GPR) requestRegister(eContext, JvmType.INT, false);
result = ifac.createReg(eContext, jvmType, lsb,
msb);
pool.transferOwnerTo(lsb, result);
pool.transferOwnerTo(msb, result);
} else {
final GPR64 reg = (GPR64) requestRegister(eContext, jvmType, false);
result = ifac.createReg(eContext, jvmType, reg);
pool.transferOwnerTo(reg, result);
}
return result;
}
/**
* Request two register for a 8-byte item.
*
* @param eContext
* @param jvmType
* @param lsb
* @param msb
* @return
*/
static DoubleWordItem requestDoubleWordRegisters(
EmitterContext eContext, int jvmType, X86Register.GPR lsb, X86Register.GPR msb) {
if (!eContext.getStream().isCode32()) {
throw new IllegalModeException("Only support in 32-bit mode");
}
final X86RegisterPool pool = eContext.getGPRPool();
final ItemFactory ifac = eContext.getItemFactory();
requestRegister(eContext, lsb);
requestRegister(eContext, msb);
final DoubleWordItem result = ifac.createReg(eContext, jvmType, lsb,
msb);
pool.transferOwnerTo(lsb, result);
pool.transferOwnerTo(msb, result);
return result;
}
/**
* Request a 64-bit register for a 8-byte item.
*
* @param eContext
* @param jvmType
* @param reg
* @return
*/
static DoubleWordItem requestDoubleWordRegister(
EmitterContext eContext, int jvmType, GPR64 reg) {
if (!eContext.getStream().isCode64()) {
throw new IllegalModeException("Only support in 64-bit mode");
}
final X86RegisterPool pool = eContext.getGPRPool();
final ItemFactory ifac = eContext.getItemFactory();
requestRegister(eContext, reg);
final DoubleWordItem result = ifac.createReg(eContext, jvmType, reg);
pool.transferOwnerTo(reg, result);
return result;
}
/**
* Request a register for calcuation, not tied to an item. Make sure to
* release the register afterwards.
*
* @param eContext
* @param reg
*/
static void requestRegister(EmitterContext eContext, X86Register reg) {
final X86RegisterPool pool = eContext.getGPRPool();
if (!pool.isFree(reg)) {
final Item i = (Item) pool.getOwner(reg);
i.spill(eContext, reg);
assertCondition(pool.isFree(reg),
"register is not free after spill");
}
assertCondition(pool.request(reg), "Request of register failed: ", reg);
}
/**
* Request a register of a given type, not tied to an item. Make sure to
* release the register afterwards.
*
* @param eContext
* @param type
* @param supportsBits8
* @return
*/
static X86Register requestRegister(EmitterContext eContext, int type,
boolean supportsBits8) {
final X86RegisterPool pool = eContext.getGPRPool();
X86Register r = pool.request(type, supportsBits8);
if (r == null) {
eContext.getVStack().push(eContext);
r = pool.request(type, supportsBits8);
}
assertCondition(r != null, "failed to request register");
return r;
}
/**
* reserve a register for an item. The item is not loaded with the register.
* The register is spilled if another item holds it.
*
* @param eContext
* @param reg the register to reserve
* @param it the item requiring the register
*/
static void requestRegister(EmitterContext eContext, X86Register reg,
Item it) {
final X86RegisterPool pool = eContext.getGPRPool();
// check item doesn't already use register
if (!it.uses(reg)) {
if (!pool.isFree(reg)) {
//TODO: spill register; make sure that the stack items
// and floating items are handled correctly
final Item i = (Item) pool.getOwner(reg);
i.spill(eContext, reg);
assertCondition(pool.isFree(reg),
"register is not free after spill");
}
assertCondition(pool.request(reg, it), "Request of register failed: ", reg);
}
}
/**
* Request one register for a single word item.
*
* @param eContext
* @param jvmType
* @param supportsBits8
* @return
*/
static WordItem requestWordRegister(EmitterContext eContext,
int jvmType, boolean supportsBits8) {
final X86RegisterPool pool = eContext.getGPRPool();
final ItemFactory ifac = eContext.getItemFactory();
final X86Register reg = requestRegister(eContext, jvmType,
supportsBits8);
final WordItem result = ifac.createReg(eContext, jvmType, reg);
pool.transferOwnerTo(reg, result);
return result;
}
/**
* Request specific one register for a single word item.
*
* @param eContext
* @param jvmType
* @param reg
* @return
*/
static WordItem requestWordRegister(EmitterContext eContext,
int jvmType, X86Register reg) {
final X86RegisterPool pool = eContext.getGPRPool();
final ItemFactory ifac = eContext.getItemFactory();
assertCondition(pool.request(reg), "Request of register failed: ", reg);
final WordItem result = ifac.createReg(eContext, jvmType, reg);
pool.transferOwnerTo(reg, result);
return result;
}
}