Red Hat Bugzilla – Bug 1261988
fragment and vertex shaders can't decrement variables by 1
Last modified: 2016-05-31 21:36:07 EDT
Description of problem:
On ppc64le and ppc64 machines that run with software rendering, the shader command to decrement a variable by 1 is never executed. This is because of a bug in the translation between tgsi and llvm ir for ppc64le and ppc64.
Because this is such a basic command in shaders, it causes a lot of failures when running the piglit test suite
Version-Release number of selected component (if applicable):
By running various piglit tests. Around 350 tests fail because of this bug. It occurs 100% of the time
Steps to Reproduce:
1. Install piglit
2. Run bin/shader_runner tests/spec/glsl-1.30/execution/fs-decrement-int.shader_test -auto
The program returns "fail"
The program should return "success"
Fixed in mesa-10.6.5-2.20150824.el7
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.