Assembly Language

saju's first post made me recall some of the things I miss in C which were so simple in x86 assembly language. For example, while doing fixed-point arithmetic with 32-bit operands, it was immensely useful that the CPU could hold the result of a multiplication (using MUL) in the EDX:EAX 64-bit register combination without overflow and that the same register combination could be used in a following division (using DIV), neatly separating the quotient and the remainder. The ADC ("Add with Carry") instruction was similarly useful for neatly handling overflows in addition. I don't know if you can achieve this in C without resorting to inline assembly. Readers of Michael Abrash's "Graphics Programming Black Book" and Oldskool PC coders will immediately realise what I'm talking about.


(Originally posted on Advogato.)

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