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IBM Releases Compiler for Power4 and G5

Posted by pudge on from the not-left-handed dept.

davids-world.com writes "IBM offers its optimized XLC compiler not just for Intel CPUs, but also for its own G5 processor (article in German at Heise). Unlike gcc, it is optimized for the G5 and achieves a major boost in speed, as first results show. I guess we will have to compare the new benchmark data (once available) with the data we get with the optimized Intel compiler for Xeon. The compiler is available for download now."

2 of 471 comments (clear)

  1. Re:Why? by Theaetetus · · Score: 5, Interesting
    I'd imagine one could cook up code to make whichever machine they want look "faster".

    Um, that's the point. IBM cooks up code to make the G5 look as fast as possible. Intel cooks up code to make the Xeon looks as fast as possible. Now compare. Fastest code/chip against the competition's fastest code/chip. The complaint in the past was that it was always the fastest code/chip of one side against a non-optimized code on the other side. Now we can have a fair shootout.

    -T

  2. I can definitely believe it by TheTranceFan · · Score: 5, Interesting
    I personally ported Macintosh Adobe Premiere 4.0 from 68000 to PowerPC. This was right when the PowerPC-based Macs were introduced (before, actually, since Apple was providing us with prerelease product). At that time, Apple's internal C compiler (then MrC) wasn't ready for primetime, nor was ThinkC. We'd been using MPW for the development, but the only good compiler for PowerPC was IBM's compiler. So I edited/built/linked the whole thing over the network on an RS/6000(?) somewhere at Adobe. I remember when I turned the optimizer on, Premiere got twice as fast, just like that.

    The IBM compiler dis some wild instruction reordering which made the optimized compiled code really hard to understand, but somehow better fitted to the processor's pipeline structure. Fortunately the only thing that broke when I turned on the optimizer was the "marching ants" used for selection, and that was the result of some way-too-fancy-casting of Pattern pointers that fooled the optimizer. I suspect the IBM compilers will continue to reign if performance is the goal.