Non-standard types: _DecimalXX, __mXXX, __int128, ymm, zmm

[hainest]

Arguments of types float, double, _Decimal32, _Decimal64 and
__m64 are in class SSE.
• Arguments of types __float128, _Decimal128 and __m128 are split
into two halves. The least significant ones belong to class SSE, the most
significant one to class SSEUP.
• Arguments of type __m256 are split into four eightbyte chunks. The least
significant one belongs to class SSE and all the others to class SSEUP.
• Arguments of type __m512 are split into eight eightbyte chunks. The least
significant one belongs to class SSE and all the others to class SSEUP.

Arguments of type __int128 offer the same operations as INTEGERs,
yet they do not fit into one general purpose register but require two registers.
For classification purposes __int128 is treated as if it were implemented
as:
typedef struct {
long low, high;
} __int128;
with the exception that arguments of type __int128 that are stored in
memory must be aligned on a 16-byte boundary.