[a64] Remove redundant zero-extension during address computation

Also changes the register to X3 by default
This commit is contained in:
Wunkolo 2024-05-06 12:51:59 -07:00
parent 018e484d6b
commit 8b4b713e0e
1 changed files with 9 additions and 10 deletions

View File

@ -25,7 +25,7 @@ volatile int anchor_memory = 0;
template <typename T>
XReg ComputeMemoryAddressOffset(A64Emitter& e, const T& guest, const T& offset,
XReg address_register = X4) {
XReg address_register = X3) {
assert_true(offset.is_constant);
int32_t offset_const = static_cast<int32_t>(offset.constant());
@ -51,27 +51,26 @@ XReg ComputeMemoryAddressOffset(A64Emitter& e, const T& guest, const T& offset,
// it via memory mapping.
e.MOV(W1, 0xE0000000 - offset_const);
e.CMP(guest.reg().toW(), W1);
e.CSET(X0, Cond::HS);
e.LSL(X0, X0, 12);
e.ADD(X0, X0, guest.reg());
e.MOV(W0, W0);
e.CSET(W0, Cond::HS);
e.LSL(W0, W0, 12);
e.ADD(W0, W0, guest.reg().toW());
} else {
// Clear the top 32 bits, as they are likely garbage.
// TODO(benvanik): find a way to avoid doing this.
e.MOV(W0, guest.reg().toW());
}
e.MOV(address_register, offset_const);
e.ADD(address_register, X0, address_register);
e.ADD(address_register, address_register, e.GetMembaseReg());
e.ADD(address_register, e.GetMembaseReg(), X0);
e.MOV(X0, offset_const);
e.ADD(address_register, address_register, X0);
return address_register;
// return e.GetMembaseReg() + e.rax + offset_const;
}
}
// Note: most *should* be aligned, but needs to be checked!
template <typename T>
XReg ComputeMemoryAddress(A64Emitter& e, const T& guest,
XReg address_register = X4) {
XReg address_register = X3) {
if (guest.is_constant) {
// TODO(benvanik): figure out how to do this without a temp.
// Since the constant is often 0x8... if we tried to use that as a