Initial community commit

Src/replicant/nu/win-x86/LockFreeLIFO.asm

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+.686
+.model FLAT
+
+PUBLIC _lifo_push
+_TEXT SEGMENT
+lifo = 4      ; size = 4
+entry = 8      ; size = 4
+_lifo_push PROC
+	mov ecx, DWORD PTR 4[esp] ; ecx holds lifo
+	mov edx, DWORD PTR 8[esp] ; edx holds the new entry
+again:
+	mov eax, DWORD PTR [ecx] ; eax holds the old head
+	mov DWORD PTR[edx], eax ; new node's 'next' is set to the old head
+	lock cmpxchg DWORD PTR [ecx], edx
+	jnz again
+	ret	0
+_lifo_push ENDP
+
+PUBLIC _lifo_pop
+_TEXT SEGMENT
+lifo = 4      ; size = 4
+_lifo_pop PROC
+	push esi
+	push ebx
+	mov	esi, DWORD PTR 12[esp] ; esi holds lifo
+again:
+    ; if re-ordered loads become an issue, we could use cmpxchg8b to read in (after zeroing ebx/ecx) or maybe use movq
+	mov edx, DWORD PTR [esi+4] ; counter
+	; or we could put an LFENCE here
+	mov eax, DWORD PTR [esi] ; pointer
+	test eax, eax
+	jz bail
+
+	mov ecx, edx ; counter
+	mov ebx, DWORD PTR [eax] ; pointer->next
+	inc ecx
+
+	lock cmpxchg8b QWORD PTR [esi]
+	jnz again
+
+bail:
+	pop ebx
+	pop esi
+	ret 0
+_lifo_pop ENDP
+
+_TEXT ENDS
+
+END
+