On 2015.09.08 at 14:40 +0200, Mathieu Malaterre wrote: > On Tue, Sep 8, 2015 at 2:00 PM, Mathieu Malaterre <malat@xxxxxxxxxx> wrote: > > FYI, > > > > On Tue, Sep 8, 2015 at 12:04 PM, Jonathan Wakely <jwakely.gcc@xxxxxxxxx> wrote: > > [...] > >> That's not the only option. You could compile one file with GCC and > >> all others with Clang and see if you can reproduce it. Repeat for each > >> file, which will narrow down the file where the problem occurs. Then > >> you can try splitting that file into smaller pieces, with one function > >> per file, and repeat the process. That would tell you which function > >> or functions get miscompiled by GCC. > > > > Ok so if I compile eveything with gcc and then only `tcd.c` using > > clang, then everything works as expected (no symptoms). > > ref: https://github.com/uclouvain/openjpeg/blob/master/src/lib/openjp2/tcd.c > > > > I'll repeat your approach to find the culprit function. > > And the culprit function is `opj_tcd_makelayer`: > > https://github.com/uclouvain/openjpeg/blob/master/src/lib/openjp2/tcd.c#L218 > > Other than the `if (dd / dr >= thresh)` I do not see anything > obviously suspicious. Looks like a x87 vs. SSE2 issue. You could try adding "-msse2 -mfpmath=sse" for the -m32 case. -- Markus
