Created attachment 120416 [details]
screenshot

In Two Worlds 2 (running in Wine 1.8-rc3) water is not rendered properly: it
looks as if textures are "split up" into several pieces, as it can be seen in
the attached screenshot.
The problem doesn't occur with the software renderer (LIBGL_ALWAYS_SOFTWARE=1).
Disabling optimizations doesn't help (NV50_PROG_OPTIMIZE=0).

According to my testing the problem was introduced by

commit abd326e81b06f58797be94bd655ee06b17a34f0c
Author: Ilia Mirkin <imirkin@alum.mit.edu>
Date:   Fri Dec 4 15:21:11 2015 -0500

    nv50/ir: propagate indirect loads into instructions

    This way $r1 = $r0 + 4; c1[$r1] becomes c1[$r0+4].

    On SM35:

    total instructions in shared programs : 6206257 -> 6185058 (-0.34%)
    total gprs used in shared programs    : 911045 -> 910722 (-0.04%)
    total local used in shared programs   : 39072 -> 39072 (0.00%)

                    local        gpr       inst      bytes
        helped           0         417        4195        4195
          hurt           0         280           0           0


Reverting the commit on current Mesa git resolves the problem here.

Apitrace log (uncompressed 150 MB):
https://drive.google.com/open?id=0B-tTbLKBl-tOQ0xNMFJlSS00S1E
The trace replays correctly on Nvidia binary drivers 340.96.

Fedora 23 32-bit
Kernel 4.4.0-rc4
X Server 1.18.0
OpenGL vendor string: nouveau
OpenGL renderer string: Gallium 0.4 on NV92
OpenGL core profile version string: 3.3 (Core Profile) Mesa 11.2.0-devel
(git-f61ceeb)
OpenGL core profile shading language version string: 3.30