[dynarmic] fix MWAIT push/pop not being handled properly on xbyak (#3875)
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push %edx is not what i wanted, nor what anybody wants, xbyak silently accepting this before was not intended
now that xbyak is updated this is an issue

the issue was simply:
a) ptr being overwritten (if it happened to be EDX/EBX/EAX) due to changed WAITPKG logic (oops)
b) xbyak not reporting wrong r32 pop/push on older versions thus missing it and now it throws an exception

Signed-off-by: lizzie <lizzie@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3875
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
This commit is contained in:
lizzie 2026-04-23 05:06:33 +02:00 committed by crueter
parent 838cc926f6
commit 417ed904f0
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@ -23,16 +23,14 @@ static const auto default_cg_mode = nullptr; //Allow RWE
namespace Dynarmic {
void EmitSpinLockLock(Xbyak::CodeGenerator& code, Xbyak::Reg64 ptr, Xbyak::Reg32 tmp, bool waitpkg) {
// TODO: this is because we lack regalloc - so better to be safe :(
if (waitpkg) {
code.push(Xbyak::util::eax);
code.push(Xbyak::util::ebx);
code.push(Xbyak::util::edx);
}
Xbyak::Label start, loop;
code.jmp(start, code.T_NEAR);
code.L(loop);
if (waitpkg) {
// TODO: this is because we lack regalloc - so better to be safe :(
code.push(Xbyak::util::rax);
code.push(Xbyak::util::rbx);
code.push(Xbyak::util::rdx);
// TODO: This clobbers EAX and EDX did we tell the regalloc?
// ARM ptr for address-monitoring
code.umonitor(ptr);
@ -49,6 +47,9 @@ void EmitSpinLockLock(Xbyak::CodeGenerator& code, Xbyak::Reg64 ptr, Xbyak::Reg32
code.umwait(Xbyak::util::ebx);
// CF == 1 if we hit the OS-timeout in IA32_UMWAIT_CONTROL without a write
// CF == 0 if we exited the wait for any other reason
code.pop(Xbyak::util::rdx);
code.pop(Xbyak::util::rbx);
code.pop(Xbyak::util::rax);
} else {
code.pause();
}
@ -57,11 +58,6 @@ void EmitSpinLockLock(Xbyak::CodeGenerator& code, Xbyak::Reg64 ptr, Xbyak::Reg32
/*code.lock();*/ code.xchg(code.dword[ptr], tmp);
code.test(tmp, tmp);
code.jnz(loop, code.T_NEAR);
if (waitpkg) {
code.pop(Xbyak::util::edx);
code.pop(Xbyak::util::ebx);
code.pop(Xbyak::util::eax);
}
}
void EmitSpinLockUnlock(Xbyak::CodeGenerator& code, Xbyak::Reg64 ptr, Xbyak::Reg32 tmp) {