[all-commits] [llvm/llvm-project] 975170: [OpenMPOpt][WIP] Expand parallel region merging

[Giorgis Georgakoudis via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 975170551283559ebe5052b6f83b2cc9e50132db
      https://github.com/llvm/llvm-project/commit/975170551283559ebe5052b6f83b2cc9e50132db
  Author: Giorgis Georgakoudis <georgakoudis1 at llnl.gov>
  Date:   2021-01-11 (Mon, 11 Jan 2021)

  Changed paths:
    M llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
    M llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
    M llvm/lib/Transforms/IPO/OpenMPOpt.cpp
    M llvm/test/Transforms/OpenMP/parallel_region_merging.ll

  Log Message:
  -----------
  [OpenMPOpt][WIP] Expand parallel region merging

The existing implementation of parallel region merging applies only to
consecutive parallel regions that have speculatable sequential
instructions in-between. This patch lifts this limitation to expand
merging with any sequential instructions in-between, except calls to
unmergable OpenMP runtime functions. In-between sequential instructions
in the merged region are sequentialized in a "master" region and any
output values are broadcasted to the following parallel regions and the
sequential region continuation of the merged region.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D90909