[http://sourceforge.net/p/ufoai/bugs/479 Item 479] imported from sourceforge.net tracker on 2013-01-28 18:21:29

The Com_ParseValue function of game/q_shared.c reads in bytes, integers and floats and packs them tightly in memory. If it first reads a byte and then a float, on PPC this causes a bus error because the float isn't properly aligned. On PowerPC, floating point values have to be 4-byte aligned, which obviously isn't the case when a byte is read followed by a float.

This function's design has to be changed. Perhaps a better version (or at least, ideas) can be snarfed from another Q2-based project that is known to work on PPC?
===== Comments Ported from Sourceforge =====

====== tlh2000 (2007-01-02 09:33:06) ======

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this function is ufo:ai only - afaik - so no 'snarfing' is possible here (correct me if i'm wrong)
====== airhead (2007-01-03 22:13:29) ======

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Here's an alignment hack. This is possibly quite heavy on resources (using just less than 4 times as much memory on PPC than i386 in the worst case), but at least it makes the game get to the main screen (and other archs don't suffer from the memory hogging). There are still issues left, the menu doesn't display the menu items text correctly and sometimes I see weird rendering artifacts in the menu screen (these may be problems with Mesa's software rendering, though).

It might be worthwhile to drop manual memory management in favor of malloc()/free() based memory management. This means memory will always be properly aligned. Unfortunately, changing the design of the parser requires quite a bit of work.

Unfortunately, as there's no software renderer for UFO:AI, I will not be able to continue work on porting efforts. Mesa's software rendering is just too slow. This is probably my last contribution to this project (until there's decent free hardware acceleration software). Best of luck with the project!
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====== sf-robot (2007-01-21 03:20:05) ======

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