SDL2 VMX bugfix
Another hat tip to Jeremy Rand, who got a fix landed for issues with VMX endianness with blitting inside the SDL library. We all care about SDL, since many games rely on it (and quite a few other things), and the issue was a real performance problem with ppc64le as at least some distros dealt with the issue by disabling it on little-endian (big-endian Power is unaffected). The patch is also faster because it moves the vector permute out of the loop, which is also the correct fix for the bug. The issue goes back all the way to the original SDL; the patch has landed on the legacy SDL 1.2.x as well as the next release of SDL 2.x, expected to be 2.28.
Jeremy added, "My patch was reviewed promptly, and it's obvious that SDL actually cares about properly supporting diverse arches, even if they don't personally use them." Amen to that.
From what I can see this was already merged and released with SDL 2.28.0 yet, if I don't disable Altivec support it still shows colors weirdly hinting at endian issues. Battle for Wesnoth being one such example. From what I see, no ABI was broken with this change so I'm a bit puzzled.
ReplyDeleteHi Alexander, could you pop onto #talos-workstation IRC to help me reproduce this?
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