<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Adding a single, meaningless if-else to a shader source leads to different image" href="https://bugs.freedesktop.org/show_bug.cgi?id=100303#c5">Comment # 5</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Adding a single, meaningless if-else to a shader source leads to different image" href="https://bugs.freedesktop.org/show_bug.cgi?id=100303">bug 100303</a> from <a class="email" href="mailto:sroland@vmware.com" title="Roland Scheidegger <sroland@vmware.com>"> Roland Scheidegger</a> <pre>(In reply to Timothy Arceri from <a href="show_bug.cgi?id=100303#c4">comment #4</a>) > (In reply to Roland Scheidegger from <a href="show_bug.cgi?id=100303#c2">comment #2</a>) > > > > So, for some reason the compiler completely eliminated the conditional > > return in the loop inside the branch and figured it will just > > unconditionally return the value corresponding to not meeting that condition > > in the loop in the original code. (In fact all code in this function with > > the exception of the return statement is now effectively dead.) > > Not sure though which lowering stage did this damage... > > I think there is a bug in do_lower_jumps(). I noticed a similar bug when > working on loop unrolling for NIR. I wrote the following tests that pass on > NIR unrolling/return lower but fail in GLSL IR. > > piglit/tests/spec/glsl-1.10/execution/vs-nested-return-sibling-loop. > shader_tes > piglit/tests/spec/glsl-1.10/execution/vs-nested-return-sibling-loop2. > shader_test Yes, that looks similar. Thease also have a return in a loop inside a conditional. Albeit the test case here even works without the sibling loop.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>