They optimized their workload for the Cells SPE's more effectively than any other developer.
Assembly isn't machine code, there is still a conversion that takes place by using an "Assembler". - If the original argument was about Assembly, then my original statements would indeed be false.
I have programmed in Assembly and have even designed a virtual CPU in my course work.
I know the difference.
Each command in assembly corresponds with a machine code instruction.
So if I wrote a program:
li $s0, 5
li $s1, 6
add $s1, $s0, $s1
Each one of these commands gets replaced with a specific opcode, and each register ID, or value gets translated to it's binary representation.
"A much more readable rendition of machine language, called assembly language, uses mnemonic codes to refer to machine code instructions, rather than using the instructions' numeric values directly. "
There is no advantage of using "machine code", over assembly because the latter is just a readable version of the other. From an optimization standpoint there's no difference.