avoid collective call inside subroutine MAPL_GetGlobalHorzIJIndex

[weiyuan-jiang]

It is expensive, inconvenient and unnecessary to have a collective call inside the subroutine MAPL_GetGlobalHorzIJIndex

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Trivial change (affects only documentation or cleanup)

Checklist:

• I have tested this change with a run of GEOSgcm (if non-trivial)
• I have added one of the required labels (0 diff, 0 diff trivial, 0 diff structural, non 0-diff)
• I have updated the CHANGELOG.md accordingly following the style of Keep a Changelog

[tclune]

Have you run this with bounds checking? The MAPL procedure that you have replaced returns the all the corners for the cells in the local domain, where the ESMF routines only return the left/south corners. (Corners that are shared by 2 or more domains are only "owned" by one domain in ESMF.)

[weiyuan-jiang]

Have you run this with bounds checking? The MAPL procedure that you have replaced returns the all the corners for the cells in the local domain, where the ESMF routines only return the left/south corners. (Corners that are shared by 2 or more domains are only "owned" by one domain in ESMF.)

Yes. I only compare one left/south corner. The other comparisons are on edge without end points.