DestinationSource Orientations

Destination/Source Orientations

Another difference between platforms has to do with the format of the assembly instructions. Depending on the processor there are typically two orientations.

Some non-80x86 processors allow the destination register to not be a source register. Thus, Register D = Register A + Register B. Or D = D + A. In C programming this is a form similar to:

D = A + B

D = D + A

The 80x86 processor family requires the destination to be one of the sources. In C programming this is similar to:

D += A

D = D + A

Proc: x86 MMX, SSE, SSE2, 3DNow!, etc.

mnemonic destination , source
paddb xmm1, xmm2

32.64-Bit 80X86 Assembly Language Architecture
32/64-Bit 80x86 Assembly Language Architecture
ISBN: 1598220020
EAN: 2147483647
Year: 2003
Pages: 191

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