/**
* @param ec
* @see org.jnode.vm.x86.compiler.l1a.Item#release(EmitterContext)
*/
private void cleanup(EmitterContext ec) {
// assertCondition(!ec.getVStack().contains(this), "Cannot release while
// on vstack");
final X86RegisterPool pool = ec.getGPRPool();
switch (getKind()) {
case Kind.GPR:
pool.release(gpr);
if (VmUtils.verifyAssertions()) VmUtils._assert(pool.isFree(gpr), "reg is free");
break;
case Kind.LOCAL:
// nothing to do
break;
case Kind.CONSTANT:
// nothing to do
break;
case Kind.FPUSTACK:
// nothing to do
break;
case Kind.STACK:
// nothing to do
break;
default:
throw new IllegalArgumentException("Invalid item kind");
}
this.gpr = null;
setKind((byte) 0);
}
/**
* Load this item into a register that is suitable for BITS8 mode.
*
* @param ec
*/
final void loadToBITS8GPR(EmitterContext ec) {
if (!isGPR() || !gpr.isSuitableForBits8()) {
final X86RegisterPool pool = ec.getGPRPool();
X86Register r = pool.request(JvmType.INT, this, true);
if (r == null) {
ec.getVStack().push(ec);
r = ec.getGPRPool().request(JvmType.INT, this, true);
}
if (VmUtils.verifyAssertions()) VmUtils._assert(r != null, "r != null");
loadTo(ec, (X86Register.GPR) r);
}
}
/** @see org.jnode.vm.x86.compiler.l1a.Item#load(EmitterContext) */
final void load(EmitterContext ec) {
if (!isGPR()) {
final X86RegisterPool pool = ec.getGPRPool();
X86Register r = pool.request(getType(), this);
if (r == null) {
final VirtualStack vstack = ec.getVStack();
vstack.push(ec);
r = pool.request(getType(), this);
}
if (VmUtils.verifyAssertions()) VmUtils._assert(r != null, "r != null");
loadTo(ec, (X86Register.GPR) r);
}
if (VmUtils.verifyAssertions()) {
verifyState(ec);
}
}
/**
* @see org.jnode.vm.x86.compiler.l1a.Item#spill(EmitterContext,
* org.jnode.assembler.x86.X86Register)
*/
final void spill(EmitterContext ec, X86Register reg) {
if (VmUtils.verifyAssertions()) {
VmUtils._assert(
isGPR() && (this.gpr.getNr() == reg.getNr()), "spill1 gpr=" + gpr + ", reg=" + reg);
}
final X86RegisterPool pool = ec.getGPRPool();
X86Register r = pool.request(getType());
if (r == null) {
ec.getVStack().push(ec);
if (getKind() == Kind.STACK) {
return;
}
r = pool.request(getType());
if (VmUtils.verifyAssertions()) VmUtils._assert(r != null, "r != null");
}
loadTo(ec, (X86Register.GPR) r);
pool.transferOwnerTo(r, this);
if (VmUtils.verifyAssertions()) {
verifyState(ec);
}
}
/**
* enquire whether the item uses a volatile register
*
* @return true, when this item uses a volatile register.
*/
final boolean usesVolatileRegister(X86RegisterPool pool) {
return (isGPR() && !pool.isCallerSaved(gpr));
}
/**
* load item with register reg. Assumes that reg is properly allocated
*
* @param ec current emitter context
* @param reg register to load the item to
*/
final void loadTo(EmitterContext ec, X86Register.GPR reg) {
if (VmUtils.verifyAssertions()) VmUtils._assert(reg != null, "Reg != null");
final X86Assembler os = ec.getStream();
final X86RegisterPool pool = ec.getGPRPool();
final VirtualStack stack = ec.getVStack();
final X86CompilerHelper helper = ec.getHelper();
if (VmUtils.verifyAssertions()) {
VmUtils._assert(!pool.isFree(reg), "reg not free");
}
switch (getKind()) {
case Kind.GPR:
if (this.gpr != reg) {
os.writeMOV(reg.getSize(), reg, this.gpr);
cleanup(ec);
}
break;
case Kind.LOCAL:
os.writeMOV(reg.getSize(), reg, helper.BP, getOffsetToFP(ec));
break;
case Kind.CONSTANT:
loadToConstant(ec, os, reg);
break;
case Kind.FPUSTACK:
// Make sure this item is on top of the FPU stack
FPUHelper.fxch(os, stack.fpuStack, this);
stack.fpuStack.pop(this);
// Convert & move to new space on normal stack
os.writeLEA(helper.SP, helper.SP, -helper.SLOTSIZE);
popFromFPU(os, helper.SP, 0);
os.writePOP(reg);
break;
case Kind.STACK:
// TODO: make sure 'this' is on top of stack
// TODO: implemen it for 64 bits
if (!stack.operandStack.isTos(this)) {
int stack_loc = stack.operandStack.stackLocation(this);
if (stack_loc < 0) throw new StackException("Item not found on stack");
stack.operandStack.makeTop(stack_loc);
// todo test it
os.writeMOV(
org.jnode.vm.x86.compiler.X86CompilerConstants.BITS32,
reg,
helper.SP,
helper.SLOTSIZE);
os.writeXCHG(
helper.SP, org.jnode.vm.x86.compiler.X86CompilerConstants.BITS32 * stack_loc, reg);
os.writeMOV(
org.jnode.vm.x86.compiler.X86CompilerConstants.BITS32,
helper.SP,
helper.SLOTSIZE,
reg);
}
if (VirtualStack.checkOperandStack) {
stack.operandStack.pop(this);
}
os.writePOP(reg);
break;
default:
throw new IllegalArgumentException("Invalid item kind");
}
setKind(Kind.GPR);
this.gpr = reg;
}
