Linked by Thom Holwerda on Fri 5th Apr 2013 16:04 UTC
General Development "For years, PC programmers used x86 assembly to write performance-critical code. However, 32-bit PCs are being replaced with 64-bit ones, and the underlying assembly code has changed. This white paper is an introduction to x64 assembly. No prior knowledge of x86 code is needed, although it makes the transition easier."
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RE[3]: Comment by Drumhellar
by transputer_guy on Fri 5th Apr 2013 20:30 UTC in reply to "RE[2]: Comment by Drumhellar"
transputer_guy
Member since:
2005-07-08

The nice thing about the early 32b x86 RISC books like "Inner Loops" was they made it quite clear which instructions should be used in assembler and which to ignore completely. So several hundred codes was reduced to a very small set of basic ops, almost all reg to reg and the load store. Basically the Pentium was a improved 486.

As for 64 bit codes, I'll have to look into that.

Reply Parent Score: 3

RE[4]: Comment by Drumhellar
by moondevil on Fri 5th Apr 2013 21:37 in reply to "RE[3]: Comment by Drumhellar"
moondevil Member since:
2005-07-08

Do you remember the Pentium programming series in Dr Dobbs from Michael Abrash?

They were all about making x86 Assembly developers how to write code to minimize processor stalls, wrong branch predictions and cache misses.

Issues that weren't a problem before.

Reply Parent Score: 3

tylerdurden Member since:
2009-03-17



They were all about making x86 Assembly developers how to write code to minimize processor stalls, wrong branch predictions and cache misses.

Issues that weren't a problem before.


That could very well be because up to the 386, the x86 family had been unpipelined in-order stack machines for all intent and purposes.

All the issues you mention are intrinsic to most in-order, pipelined, superscalar designs.

Edited 2013-04-05 22:00 UTC

Reply Parent Score: 2

transputer_guy Member since:
2005-07-08

I did get Dr Dobbs from time to time, but I also have the Michael Abrash book too (Zenn of code optimization, + graphic prog), a lot similar to the Inner Loops. I like the latter because I was only interested in certain types of asm code like JPEG DCT and well inner loops. Its always near by.

Ultimately I let the C compiler do the work of compiling C fragments that are 1 to 1 to asm opcodes, all inline. It just looks nicer than opting into the uglier asm syntax. I never learnt to use the mmx or sse stuff at all, I copped out.

Reply Parent Score: 2