<li>LIBGL_DEBUG - If defined debug information will be printed to stderr.
If set to 'verbose' additional information will be printed.
<li>LIBGL_DRIVERS_PATH - colon-separated list of paths to search for DRI drivers
-<li>LIBGL_ALWAYS_INDIRECT - forces an indirect rendering context/connection.
-<li>LIBGL_ALWAYS_SOFTWARE - if set, always use software rendering
-<li>LIBGL_NO_DRAWARRAYS - if set do not use DrawArrays GLX protocol (for debugging)
+<li>LIBGL_ALWAYS_INDIRECT - if set to `true`, forces an indirect rendering context/connection.
+<li>LIBGL_ALWAYS_SOFTWARE - if set to `true`, always use software rendering
+<li>LIBGL_NO_DRAWARRAYS - if set to `true`, do not use DrawArrays GLX protocol (for debugging)
<li>LIBGL_SHOW_FPS - print framerate to stdout based on the number of glXSwapBuffers
calls per second.
-<li>LIBGL_DRI3_DISABLE - disable DRI3 if set (the value does not matter)
+<li>LIBGL_DRI3_DISABLE - disable DRI3 if set to `true`.
</ul>
<li>MESA_NO_MMX - if set, disables Intel MMX optimizations
<li>MESA_NO_3DNOW - if set, disables AMD 3DNow! optimizations
<li>MESA_NO_SSE - if set, disables Intel SSE optimizations
+<li>MESA_NO_ERROR - if set to 1, error checking is disabled as per KHR_no_error.
+ This will result in undefined behaviour for invalid use of the api, but
+ can reduce CPU use for apps that are known to be error free.</li>
<li>MESA_DEBUG - if set, error messages are printed to stderr. For example,
if the application generates a GL_INVALID_ENUM error, a corresponding error
message indicating where the error occurred, and possibly why, will be
printed to stderr.<br>
- If the value of MESA_DEBUG is 'FP' floating point arithmetic errors will
- generate exceptions.
+
+ For release builds, MESA_DEBUG defaults to off (no debug output).
+
+ MESA_DEBUG accepts the following comma-separated list of named
+ flags, which adds extra behaviour to just set MESA_DEBUG=1:
+ <ul>
+ <li>silent - turn off debug messages. Only useful for debug builds.</li>
+ <li>flush - flush after each drawing command</li>
+ <li>incomplete_tex - extra debug messages when a texture is incomplete</li>
+ <li>incomplete_fbo - extra debug messages when a fbo is incomplete</li>
+ <li>context - create a debug context (see GLX_CONTEXT_DEBUG_BIT_ARB) and
+ print error and performance messages to stderr (or MESA_LOG_FILE).</li>
+ </ul>
<li>MESA_LOG_FILE - specifies a file name for logging all errors, warnings,
etc., rather than stderr
<li>MESA_TEX_PROG - if set, implement conventional texture env modes with
glGetString(GL_SHADING_LANGUAGE_VERSION). Valid values are integers, such as
"130". Mesa will not really implement all the features of the given language version
if it's higher than what's normally reported. (for developers only)
+<li>MESA_GLSL_CACHE_DISABLE - if set to `true`, disables the GLSL shader cache
+<li>MESA_GLSL_CACHE_MAX_SIZE - if set, determines the maximum size of
+the on-disk cache of compiled GLSL programs. Should be set to a number
+optionally followed by 'K', 'M', or 'G' to specify a size in
+kilobytes, megabytes, or gigabytes. By default, gigabytes will be
+assumed. And if unset, a maximum size of 1GB will be used. Note: A separate
+cache might be created for each architecture that Mesa is installed for on
+your system. For example under the default settings you may end up with a 1GB
+cache for x86_64 and another 1GB cache for i386.
+<li>MESA_GLSL_CACHE_DIR - if set, determines the directory to be used
+for the on-disk cache of compiled GLSL programs. If this variable is
+not set, then the cache will be stored in $XDG_CACHE_HOME/mesa (if
+that variable is set), or else within .cache/mesa within the user's
+home directory.
<li>MESA_GLSL - <a href="shading.html#envvars">shading language compiler options</a>
<li>MESA_NO_MINMAX_CACHE - when set, the minmax index cache is globally disabled.
+<li>MESA_SHADER_CAPTURE_PATH - see <a href="shading.html#capture">Capturing Shaders</a></li>
+<li>MESA_SHADER_DUMP_PATH and MESA_SHADER_READ_PATH - see <a href="shading.html#replacement">Experimenting with Shader Replacements</a></li>
+<li>MESA_VK_VERSION_OVERRIDE - changes the Vulkan physical device version
+ as returned in VkPhysicalDeviceProperties::apiVersion.
+ <ul>
+ <li>The format should be MAJOR.MINOR[.PATCH]</li>
+ <li>This will not let you force a version higher than the driver's
+ instance versionas advertised by vkEnumerateInstanceVersion</li>
+ <li>This can be very useful for debugging but some features may not be
+ implemented correctly. (For developers only)</li>
+ </ul>
+</li>
</ul>
This is useful for debugging hangs, etc.</li>
<li>INTEL_DEBUG - a comma-separated list of named flags, which do various things:
<ul>
- <li>tex - emit messages about textures.</li>
- <li>state - emit messages about state flag tracking</li>
- <li>blit - emit messages about blit operations</li>
- <li>miptree - emit messages about miptrees</li>
- <li>perf - emit messages about performance issues</li>
- <li>perfmon - emit messages about AMD_performance_monitor</li>
+ <li>ann - annotate IR in assembly dumps</li>
+ <li>aub - dump batches into an AUB trace for use with simulation tools</li>
<li>bat - emit batch information</li>
- <li>pix - emit messages about pixel operations</li>
+ <li>blit - emit messages about blit operations</li>
+ <li>blorp - emit messages about the blorp operations (blits & clears)</li>
<li>buf - emit messages about buffer objects</li>
- <li>reg - emit messages about regions</li>
+ <li>clip - emit messages about the clip unit (for old gens, includes the CLIP program)</li>
+ <li>color - use color in output</li>
+ <li>cs - dump shader assembly for compute shaders</li>
+ <li>do32 - generate compute shader SIMD32 programs even if workgroup size doesn't exceed the SIMD16 limit</li>
+ <li>dri - emit messages about the DRI interface</li>
<li>fbo - emit messages about framebuffers</li>
<li>fs - dump shader assembly for fragment shaders</li>
<li>gs - dump shader assembly for geometry shaders</li>
- <li>sync - emit messages about synchronization</li>
+ <li>hex - print instruction hex dump with the disassembly</li>
+ <li>l3 - emit messages about the new L3 state during transitions</li>
+ <li>miptree - emit messages about miptrees</li>
+ <li>no8 - don't generate SIMD8 fragment shader</li>
+ <li>no16 - suppress generation of 16-wide fragment shaders. useful for debugging broken shaders</li>
+ <li>nocompact - disable instruction compaction</li>
+ <li>nodualobj - suppress generation of dual-object geometry shader code</li>
+ <li>norbc - disable single sampled render buffer compression</li>
+ <li>optimizer - dump shader assembly to files at each optimization pass and iteration that make progress</li>
+ <li>perf - emit messages about performance issues</li>
+ <li>perfmon - emit messages about AMD_performance_monitor</li>
+ <li>pix - emit messages about pixel operations</li>
<li>prim - emit messages about drawing primitives</li>
- <li>vert - emit messages about vertex assembly</li>
- <li>dri - emit messages about the DRI interface</li>
+ <li>reemit - mark all state dirty on each draw call</li>
<li>sf - emit messages about the strips & fans unit (for old gens, includes the SF program)</li>
- <li>stats - enable statistics counters. you probably actually want perfmon or intel_gpu_top instead.</li>
+ <li>shader_time - record how much GPU time is spent in each shader</li>
+ <li>spill_fs - force spilling of all registers in the scalar backend (useful to debug spilling code)</li>
+ <li>spill_vec4 - force spilling of all registers in the vec4 backend (useful to debug spilling code)</li>
+ <li>state - emit messages about state flag tracking</li>
+ <li>submit - emit batchbuffer usage statistics</li>
+ <li>sync - after sending each batch, emit a message and wait for that batch to finish rendering</li>
+ <li>tcs - dump shader assembly for tessellation control shaders</li>
+ <li>tes - dump shader assembly for tessellation evaluation shaders</li>
+ <li>tex - emit messages about textures.</li>
<li>urb - emit messages about URB setup</li>
+ <li>vert - emit messages about vertex assembly</li>
<li>vs - dump shader assembly for vertex shaders</li>
- <li>clip - emit messages about the clip unit (for old gens, includes the CLIP program)</li>
- <li>aub - dump batches into an AUB trace for use with simulation tools</li>
- <li>shader_time - record how much GPU time is spent in each shader</li>
- <li>no16 - suppress generation of 16-wide fragment shaders. useful for debugging broken shaders</li>
- <li>blorp - emit messages about the blorp operations (blits & clears)</li>
- <li>nodualobj - suppress generation of dual-object geometry shader code</li>
- <li>optimizer - dump shader assembly to files at each optimization pass and iteration that make progress</li>
</ul>
+<li>INTEL_SCALAR_VS (or TCS, TES, GS) - force scalar/vec4 mode for a shader stage (Gen8-9 only)</li>
+<li>INTEL_PRECISE_TRIG - if set to 1, true or yes, then the driver prefers
+ accuracy over performance in trig functions.</li>
</ul>
<li>GALLIUM_HUD_TOGGLE_SIGNAL - toggle visibility via user specified signal.
Especially useful to toggle hud at specific points of application and
disable for unencumbered viewing the rest of the time. For example, set
- GALLIUM_HUD_VISIBLE to false and GALLIUM_HUD_SIGNAL_TOGGLE to 10 (SIGUSR1).
+ GALLIUM_HUD_VISIBLE to false and GALLIUM_HUD_TOGGLE_SIGNAL to 10 (SIGUSR1).
Use kill -10 <pid> to toggle the hud as desired.
+<li>GALLIUM_HUD_DUMP_DIR - specifies a directory for writing the displayed
+ hud values into files.
+<li>GALLIUM_DRIVER - useful in combination with LIBGL_ALWAYS_SOFTWARE=true for
+ choosing one of the software renderers "softpipe", "llvmpipe" or "swr".
<li>GALLIUM_LOG_FILE - specifies a file for logging all errors, warnings, etc.
rather than stderr.
<li>GALLIUM_PRINT_OPTIONS - if non-zero, print all the Gallium environment
See src/mesa/state_tracker/st_debug.c for other options.
</ul>
+<h3>Clover state tracker environment variables</h3>
+
+<ul>
+<li>CLOVER_EXTRA_BUILD_OPTIONS - allows specifying additional compiler and linker
+ options. Specified options are appended after the options set by the OpenCL
+ program in clBuildProgram.
+<li>CLOVER_EXTRA_COMPILE_OPTIONS - allows specifying additional compiler
+ options. Specified options are appended after the options set by the OpenCL
+ program in clCompileProgram.
+<li>CLOVER_EXTRA_LINK_OPTIONS - allows specifying additional linker
+ options. Specified options are appended after the options set by the OpenCL
+ program in clLinkProgram.
+</ul>
+
+
<h3>Softpipe driver environment variables</h3>
<ul>
<li>SOFTPIPE_DUMP_FS - if set, the softpipe driver will print fragment shaders
<li>LP_PERF - a comma-separated list of options to selectively no-op various
parts of the driver. See the source code for details.
<li>LP_NUM_THREADS - an integer indicating how many threads to use for rendering.
- Zero turns of threading completely. The default value is the number of CPU
+ Zero turns off threading completely. The default value is the number of CPU
cores present.
</ul>
(will often result in incorrect rendering).
<li>SVGA_DEBUG - for dumping shaders, constant buffers, etc. See the code
for details.
+<li>SVGA_EXTRA_LOGGING - if set, enables extra logging to the vmware.log file,
+such as the OpenGL program's name and command line arguments.
<li>See the driver code for other, lesser-used variables.
</ul>
+<h3>WGL environment variables</h3>
+<ul>
+<li>WGL_SWAP_INTERVAL - to set a swap interval, equivalent to calling
+wglSwapIntervalEXT() in an application. If this environment variable
+is set, application calls to wglSwapIntervalEXT() will have no effect.
+</ul>
<h3>VA-API state tracker environment variables</h3>
<ul>
</ul>
+<h3>VC4 driver environment variables</h3>
+<ul>
+<li>VC4_DEBUG - a comma-separated list of named flags, which do various things:
+<ul>
+ <li>cl - dump command list during creation</li>
+ <li>qpu - dump generated QPU instructions</li>
+ <li>qir - dump QPU IR during program compile</li>
+ <li>nir - dump NIR during program compile</li>
+ <li>tgsi - dump TGSI during program compile</li>
+ <li>shaderdb - dump program compile information for shader-db analysis</li>
+ <li>perf - print during performance-related events</li>
+ <li>norast - skip actual hardware execution of commands</li>
+ <li>always_flush - flush after each draw call</li>
+ <li>always_sync - wait for finish after each flush</li>
+ <li>dump - write a GPU command stream trace file (VC4 simulator only)</li>
+</ul>
+</ul>
+
+
<p>
Other Gallium drivers have their own environment variables. These may change
frequently so the source code should be consulted for details.