mirror of
https://github.com/FEX-Emu/FEX.git
synced 2026-10-14 10:00:42 +02:00
Ryan Houdek
e817f5d98c
A bit meta since it needs to JIT some minor code but easy enough. Ensures something like #1517 won't happen again.
45 lines
857 B
NASM
45 lines
857 B
NASM
%ifdef CONFIG
|
|
{
|
|
"RegData": {
|
|
"RAX": "0x41424344"
|
|
},
|
|
"Mode": "32BIT"
|
|
}
|
|
%endif
|
|
|
|
; Tests for 32-bit signed displacement wrapping
|
|
; Testing for underflow specifically
|
|
; Will crash or hit the code we emit to memory
|
|
|
|
; We map ten pages to 0xe000'0000
|
|
; Generate a mov eax + hlt over there first
|
|
; 0xb8'44'43'42'41: mov eax, 0x41424344
|
|
; 0xf4: hlt
|
|
|
|
mov ebx, 0xe0000000
|
|
mov al, 0xb8
|
|
mov byte [ebx], al
|
|
mov eax, 0x41424344
|
|
mov dword [ebx + 1], eax
|
|
mov al, 0xf4
|
|
mov byte [ebx + 5], al
|
|
|
|
; Do a jump dance to stop multiblock from trying to optimize
|
|
; Otherwise it will JIT code from 0xe000'0000 before written
|
|
lea ebx, [rel next]
|
|
jmp ebx
|
|
next:
|
|
|
|
; Move temp to eax to overwrite
|
|
mov eax, 0
|
|
|
|
; Clear the lower flags so the branch gets taken
|
|
sahf
|
|
|
|
; This is dependent on where it is in the code!
|
|
jnb -0x20000000
|
|
|
|
; Definitely wrong if we hit here
|
|
mov eax, -1
|
|
hlt
|