[PATCH] D26437: Use -fno-unit-at-a-time and -funit-at-a-time

Stanislav Mekhanoshin via llvm-commits llvm-commits at lists.llvm.org
Thu Nov 10 12:10:23 PST 2016


rampitec added a comment.

In https://reviews.llvm.org/D26437#590617, @tejohnson wrote:

> I've added Richard Smith as a reviewer, as he is more familiar with the Clang FE. What is the specific issue requiring disabling unit at a time?


Thank you. The issue appeared while building opencl library. Under unit-at-a-time mode PassManagerBuilder adds FunctionAttrs pass (createPostOrderFunctionAttrsLegacyPass). This pass has removeConvergentAttrs function which removes unused convergent attribute from functions. Functions in the library are unused, so it has removed the attribute in particular from sub_group_barrier, which then lead to OpenCL conformance subgroups test to hang.


Repository:
  rL LLVM

https://reviews.llvm.org/D26437





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