Talk:Historical Notes on CISC and RISC

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Anyone interested in RISC vs CISC should give Sun Microsystems libmath a read (it's in the BSD source trees). It's amazing how many thousands of lines of C they wrote, to do things that take a single instruction on Intel X87 CISC FPU. They also used a lot of type punning, so the code Sun wrote in the 90's might stop working with modern compilers. But X87 still works as it always has, and always will.

  • (Above by Norepinephrine. Please sign posts on talk pages with 4 '~' characters.)
  • There are several objections to this. A FPU is not a "computer" in the sense of RISC or CISC, it's not a central processing unit. Floating point emulation was commonly needed until some time in the 90s. (Later in embedded hardware.) The x87 was never the only FPU around; other CPU ranges had their own. (Until the Pentium, the x87 was slower than other architectures' FPUs, including SPARC's.) Finally, the big reason: If I remember right, libmath is a standard library which does a whole lot more than floating point emulation. It's also responsible for extended-precision arithmetic, for instance 100-digit numbers; a very hard thing to make high-performance. (I may be mixing it up with libm.) Eekee 18:25, 11 June 2019 (CDT)
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