x86-64 Calling Conventions

	A	B	C	D
1
2	__vectorcall x86	pass by	fallback	return
3	Floating point	first 6 parameters value in XMM[0-5]	reference in stack	value in XMM0
4	Integer	first 2 parameters value in ECX, EDX	value in stack	EDX:EAX
5	Aggregates 8, 16, 32, 64	first 2 parameters value in ECX, EDX	value in stack	EDX:EAX
6	Aggregates (other)	reference in stack
7	Vector	first 6 parameters value in XMM[0-5], YMM[0-5]	reference in stack	XMM0 or YMM0, depending on size
8	Vector aggregates	XMM[0-5], YMM[0-5]	reference in stack	XMM[0-3] or YMM[0-3]
9
10	__vectorcall x64	pass by	fallback	return
11	Floating point	first 6 parameters value in XMM[0-5]	reference in stack	value in XMM0
12	Integer	first 4 parameters value in RCX, RDX, R8, R9	value in stack	RAX if fits into 64 bits
13	Aggregates 8, 16, 32, 64	first 4 parameters value in RCX, RDX, R8, R9	value in stack	RAX
14	Aggregates (other)	reference in stack
15	Vector	first 6 parameters value in XMM[0-5], YMM[0-5]	reference in stack	XMM0 or YMM0, depending on size
16	Vector aggregates	first 4 value in XMM[0-5], YMM[0-5]	reference in stack	XMM[0-3] or YMM[0-3]
17
18	Microsoft x64 ABI	pass by	fallback	return
19	Floating point	first 4 parameters value in XMM[0-3]	value in stack	XMM0
20	Integer	first 4 parameters value in RCX, RDX, R8, R9	value in stack	RAX if fits into 64 bits
21	Aggregates 8, 16, 32, 64	first 4 parameters value in RCX, RDX, R8, R9	value in stack	RAX
22	Aggregates (other)	first 4 parameters reference in RCX, RDX, R8, R9	reference in stack
23	vector	first 4 parameters reference in RCX, RDX, R8, R9	reference in stack	XMM0
24	Stack alignment is 16 bytes
25
26	System V x64 ABI	pass by	fallback	return
27	Floating point	first 8 parameters value in XMM[0-7]	value in stack	XMM0
28	Integer	first 6 parameters value in RDI, RSI, RDX, RCX, R8, R9	value in stack	RDX:RAX
29	Aggregates 8, 16, 32, 64			RDX:RAX
30	Aggregates (other)
31	vector
32	Stack alignment is 16 bytes
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