Bug 69285

Summary: Enabling LLVM results in substantially different rendering
Product: Mesa Reporter: Charles Huber <genpfault>
Component: Drivers/Gallium/llvmpipeAssignee: mesa-dev
Status: RESOLVED MOVED QA Contact:
Severity: normal    
Priority: medium    
Version: git   
Hardware: x86 (IA32)   
OS: Linux (All)   
i915 platform: i915 features:
Attachments: SDL 1.2-based test case
Output with --disable-gallium-llvm
Output with --enable-gallium-llvm

Description Charles Huber 2013-09-12 18:26:29 UTC
Created attachment 85735 [details]
SDL 1.2-based test case

A simple OpenGL ES 2.0 checkerboard shader has significantly different output when LLVM is enabled on softpipe.

I think the non-LLVM output is correct.

$ gcc --version
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3

$ uname -a
Linux garmin-vm 3.2.0-53-generic #81-Ubuntu SMP Thu Aug 22 21:03:54 UTC 2013 i686 i686 i386 GNU/Linux

$ lsb_release -a
Distributor ID:	Ubuntu
Description:	Ubuntu 12.04.3 LTS
Release:	12.04
Codename:	precise

# llvm 3.3
./configure --disable-assertions

# mesa 9.2.0 llvm enabled
./configure \
--enable-gles2 \
--enable-gallium-egl \
--with-egl-platforms="x11" \
--with-gallium-drivers="swrast" \
--with-dri-drivers="" \
--disable-xvmc \
--enable-gallium-llvm \

# mesa 9.2.0 llvm disabled
./configure \
--enable-gles2 \
--enable-gallium-egl \
--with-egl-platforms="x11" \
--with-gallium-drivers="swrast" \
--with-dri-drivers="" \
--disable-xvmc \
--disable-gallium-llvm \

# build
g++ main.cpp -lSDL -L/usr/local/lib -lEGL -lGLESv2

# run
LD_LIBRARY_PATH=/usr/local/lib EGL_SOFTWARE=true ./a.out
Comment 1 Charles Huber 2013-09-12 18:27:21 UTC
Created attachment 85736 [details]
Output with --disable-gallium-llvm
Comment 2 Charles Huber 2013-09-12 18:27:42 UTC
Created attachment 85737 [details]
Output with --enable-gallium-llvm
Comment 3 Charles Huber 2013-12-09 17:23:32 UTC
Still broken in 10.0.
Comment 4 Charles Huber 2014-01-16 16:55:10 UTC
Still broken in 10.0.2 with LLVM 3.4.

Slightly different configure required for 3.4:

./configure \
--disable-assertions \
--enable-terminfo=no \
--enable-curses=no \
Comment 5 Charles Huber 2014-01-16 17:10:56 UTC
Broken on current git master (188383591d6d657b557a5407ee9b7b993f79c53b) too.
Comment 6 GitLab Migration User 2019-09-18 18:31:23 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

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