[gdal-dev] [SOLVED] Re: Different results when reading a GeoTIFF with GDAL 2.1.2 vs 3.x

[Even Rouault]

Hi,

so after investigation this was not an issue with the detection of SSSE3, but 
a bug in the SSE2-only optimization that was then used when SSSE3 is missing.
Affected GeoTIFF files with 2 bands of type=Byte and pixel-interleaving layout 
(PlanarConfiguration=Contig)

Fixed by https://github.com/OSGeo/gdal/pull/2143 and backported to 3.0 and 2.4 
branches

(the interesting thing is that this code path was unit tested, but with data 
with a specific bit pattern that hid the bug, a bit like someone writting
let addition(a,b) = a | b and believing it works correctly if testing 
addition(2,4), addition(5,24) etc. )

Even

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