------- Comment #40 from astrange at ithinksw dot com 2009-10-18 19:56 ------- Linked from http://x264dev.multimedia.cx/?p=185, I'd forgotten all about the ridiculous flamewar in this one.
Just as a note, the actual definitions of the four variables (from liba52): x2k = x + 2 * k; x3k = x2k + 2 * k; x4k = x3k + 2 * k; wB = wTB + 2 * k; Also, the asm inputs are silly - output 0 is the same as input 6 for no reason, and the same with output 2 and input 7. So change those to "+m" and change %6/%7 to %0/%2. That doesn't actually change anything, even though it should free two registers. It works with gcc 4.5 -O0 -fno-pic -fomit-frame-pointer, but not without one of those flags. Looks like that's because it's allocating 2 more registers for the unused fake inputs for the "+m" - change it to "=m" and it works with one flag removed, but still not both. So there's a specific bug. And of course it all works at -O1 because it doesn't have to use registers there. So maybe it should just do that. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11203
