Commits on Jan 25, 2024

1. [Flang][OpenMP] Use simdloop operation only for omp simd pragma …

   OpenMP standard differentiates between omp simd (2.9.3.1) and
   omp do/for simd (2.9.3.2 for OpenMP 5.0 standard) pragmas.
   The first one describes the loop which needs to be vectorized.
   The second pragma describes the loop which needs to be workshared
   between existing threads. Each thread can use SIMD instructions
   to execute its chunk of the loop.
   
   That's why we need to model
   !$omp simd
     do-loop
   as omp.simdloop operation and add compiler hints for vectorization.
   
   The worksharing loop:
   !$omp do simd
     do-loop
   should be represented as worksharing loop.
   
   Currently Flang denotes both type of OpenMP pragmas by omp.simdloop
   operation. In consequence we cannot differentiate between:
   !$omp parallel simd
      do-loop
   and
   !$omp parallel do simd
      do-loop
   The second loop should be workshared between multiple threads.
   The first one describes the loop which needs to be redundantly
   executed by multiple threads. Current Flang implementation
   does not perform worksharing for `!$omp do simd` pragma and
   generates valid code only for first case.

   

   DominikAdamski committed Jan 25, 2024
   Configuration menu

   • View commit details
   • Copy full SHA for 3bc8b58
   • Browse repository at this point

   Copy the full SHA

   3bc8b58 View commit details

   Browse the repository at this point in the history