Created attachment 128570 [details]
Simple test case
When using multiple builtin functions, linking of a shader can fail if temporary variables of the GLSL compiler collide.
builtin_builder::binop creates variables named "x" and "y" for the parameters of builtin functions. Later, ir_call::generate_inline inlines the call to the builtins. It clones the variables (without changing the name) and assigns the function inputs to them.
This can cause a collision of variable names, e. g. when using multiple builtin functions with parameters of different types. The attached test case can be used to reproduce the problem.
I can work around the problem by adding a sequence number and possibly a prefix to the variable names but I am not sure if that is the correct solution.
Thanks to imirkin and robclark for helping me to figure this out on IRC.
Patch on list:
Fixed on master:
Author: Kenneth Graunke <firstname.lastname@example.org>
Date: Mon Dec 19 14:32:57 2016 -0800
glsl: Use ir_var_temporary when generating inline functions.