docs: add INTEL_SHADER_ASM_READ_PATH description
It was implemented in
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/955
Signed-off-by: Danylo Piliaiev <danylo.piliaiev@globallogic.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Sagar Ghuge <sagar.ghuge@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6895>
diff --git a/docs/envvars.rst b/docs/envvars.rst
index c0f568a..fa414bd 100644
--- a/docs/envvars.rst
+++ b/docs/envvars.rst
@@ -331,6 +331,20 @@
``INTEL_PRECISE_TRIG``
if set to 1, true or yes, then the driver prefers accuracy over
performance in trig functions.
+``INTEL_SHADER_ASM_READ_PATH``
+ if set, determines the directory to be used for overriding shader
+ assembly. The binaries with custom assembly should be placed in
+ this folder and have a name formatted as ``sha1_of_assembly.bin``.
+ The sha1 of a shader assembly is printed when assembly is dumped via
+ corresponding ``INTEL_DEBUG`` flag (e.g. ``vs`` for vertex shader).
+ A binary could be generated from a dumped assembly by ``i965_asm``.
+ For ``INTEL_SHADER_ASM_READ_PATH`` to work it is necessary to enable
+ dumping of corresponding shader stages via ``INTEL_DEBUG``.
+ It is advised to use ``nocompact`` flag of ``INTEL_DEBUG`` when
+ dumping and overriding shader assemblies.
+ The success of assembly override would be signified by "Successfully
+ overrode shader with sha1 <sha1>" in stderr replacing the original
+ assembly.
Radeon driver environment variables (radeon, r200, and r300g)
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