[all-commits] [llvm/llvm-project] 36bfdb: [Clang][Driver] Disable llvm passes for the first ...

[Sergey Dmitriev via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 36bfdb7096cfe1925448e408ec72f1a6bdc4cd2c
      https://github.com/llvm/llvm-project/commit/36bfdb7096cfe1925448e408ec72f1a6bdc4cd2c
  Author: Sergey Dmitriev <serguei.n.dmitriev at intel.com>
  Date:   2020-01-30 (Thu, 30 Jan 2020)

  Changed paths:
    M clang/lib/Driver/ToolChains/Clang.cpp
    M clang/test/Driver/openmp-offload.c

  Log Message:
  -----------
  [Clang][Driver] Disable llvm passes for the first host OpenMP offload compilation

Summary: With OpenMP offloading host compilation is done in two phases to capture host IR that is passed to all device compilations as input. But it turns out that we currently run entire LLVM optimization pipeline on host IR on both compilations which may have unpredictable effects on the resulting code. This patch fixes this problem by disabling LLVM passes on the first compilation, so the host IR that is passed to device compilations will be captured right after front end.

Reviewers: ABataev, jdoerfert, hfinkel

Reviewed By: ABataev

Subscribers: guansong, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73721