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https://github.com/FEX-Emu/FEX.git
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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
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{
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"RegData": {
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"RAX": "0x41424344"
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},
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"Mode": "32BIT"
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}
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%endif
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; Tests for 32-bit signed displacement wrapping
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; Testing for underflow specifically
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; Will crash or hit the code we emit to memory
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; We map ten pages to 0xe000'0000
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; Generate a mov eax + hlt over there first
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; 0xb8'44'43'42'41: mov eax, 0x41424344
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; 0xf4: hlt
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mov ebx, 0xe0000000
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mov al, 0xb8
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mov byte [ebx], al
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mov eax, 0x41424344
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mov dword [ebx + 1], eax
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mov al, 0xf4
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mov byte [ebx + 5], al
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; Do a jump dance to stop multiblock from trying to optimize
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; Otherwise it will JIT code from 0xe000'0000 before written
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lea ebx, [rel next]
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jmp ebx
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next:
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; Move temp to eax to overwrite
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mov eax, 0
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; Clear the lower flags so the branch gets taken
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sahf
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; This is dependent on where it is in the code!
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jnb -0x20000000
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; Definitely wrong if we hit here
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mov eax, -1
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hlt
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