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convert relative calls to absolute indirect calls on x86_64, in case we need to jump further than a 32-bit displacement will allow

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This commit is contained in:
Joel Dice 2008-04-13 11:16:27 -06:00
parent 85712d183b
commit d77ffa8e21
1 changed files with 47 additions and 15 deletions
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62
src/compiler.cpp
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@ -1131,13 +1131,19 @@ argumentFootprint(unsigned count)
}
void
rex(Context* c)
rex(Context* c, uint8_t mask, Register r)
{
if (BytesPerWord == 8) {
c->code.append(0x48);
c->code.append(mask | ((r & 8) >> 3));
}
}
void
rex(Context* c)
{
rex(c, 0x48, rax);
}
void
encode(Context* c, uint8_t* instruction, unsigned length, int a, Register b,
int32_t displacement, int index, unsigned scale)
@ -1203,8 +1209,9 @@ RegisterOperand::apply(Context* c, Operation op)
{
switch (op) {
case call: {
if (value(c) & 8) rex(c, 0x40, value(c));
c->code.append(0xff);
c->code.append(0xd0 | value(c));
c->code.append(0xd0 | (value(c) & 7));
} break;
case jmp:
@ -1410,8 +1417,8 @@ RegisterOperand::accept(Context* c, Operation op,
case mov8: {
assert(c, BytesPerWord == 8 or op == mov4); // todo
rex(c);
c->code.append(0xb8 | value(c));
rex(c, 0x48, value(c));
c->code.append(0xb8 | (value(c) & 7));
c->code.appendAddress(operand->value);
} break;
@ -1620,14 +1627,27 @@ AddressOperand::apply(Context* c, Operation op)
{
switch (op) {
case alignedCall: {
while ((c->code.length() + 1) % 4) {
c->code.append(0x90);
if (BytesPerWord == 8) {
while ((c->code.length() + 2) % 8) {
c->code.append(0x90);
}
} else {
while ((c->code.length() + 1) % 4) {
c->code.append(0x90);
}
}
apply(c, call);
} break;
case call: {
unconditional(c, 0xe8, this);
if (BytesPerWord == 8) {
RegisterOperand* t = temporary(c, r10);
t->accept(c, mov, this);
t->apply(c, call);
t->release(c);
} else {
unconditional(c, 0xe8, this);
}
} break;
case jmp:
@ -1650,7 +1670,6 @@ AddressOperand::apply(Context* c, Operation op)
conditional(c, 0x8d, this);
break;
case jl:
conditional(c, 0x8c, this);
break;
@ -2836,13 +2855,26 @@ class MyCompiler: public Compiler {
}
virtual void updateCall(void* returnAddress, void* newTarget) {
uint8_t* instruction = static_cast<uint8_t*>(returnAddress) - 5;
assert(&c, *instruction == 0xE8);
assert(&c, reinterpret_cast<uintptr_t>(instruction + 1) % 4 == 0);
if (BytesPerWord == 8) {
uint8_t* instruction = static_cast<uint8_t*>(returnAddress) - 13;
assert(&c, instruction[0] == 0x49);
assert(&c, instruction[1] == 0xba);
assert(&c, instruction[10] == 0x41);
assert(&c, instruction[11] == 0xff);
assert(&c, instruction[12] == 0xd2);
assert(&c, reinterpret_cast<uintptr_t>(instruction + 2) % 8 == 0);
int32_t v = static_cast<uint8_t*>(newTarget)
- static_cast<uint8_t*>(returnAddress);
memcpy(instruction + 1, &v, 4);
intptr_t v = reinterpret_cast<intptr_t>(newTarget);
memcpy(instruction + 2, &v, 8);
} else {
uint8_t* instruction = static_cast<uint8_t*>(returnAddress) - 5;
assert(&c, *instruction == 0xE8);
assert(&c, reinterpret_cast<uintptr_t>(instruction + 1) % 4 == 0);
int32_t v = static_cast<uint8_t*>(newTarget)
- static_cast<uint8_t*>(returnAddress);
memcpy(instruction + 1, &v, 4);
}
}
virtual void dispose() {