en Copyright 2015 Java http://172.16.0.5:8080/history/llvm-project-15.0.7/flang/test/Lower/do_loop_unstructured.f90#aa0e167f [Flang] Lower Unstructured do loopsThe FIR `do_loop` is designed as a structured operation with a singleblock inside it. Presence of unstructured constructs like jumps, exitsinside the loop will cause the loop to be marked as unstructured. Theseloops are lowered using the `control-flow` dialect branch operations.Fortran semantics do not allow the loop variable to be modified insidethe loop. To prevent accidental modification, the iteration of theloop is modeled by two variables, trip-count and loop-variable.-> The trip-count and loop-variable are initialized in the pre-header.The trip-count is set as (end-start+step)/step where end, start andstep have the usual meanings. The loop-variable is initialized to start.-> The header block contains a conditional branch instruction whichselects between branching to the body of the loop or the exit blockdepending on the value of the trip-count.-> Inside the body, the trip-count is decremented and the loop-variableincremented by the step value. Finally it branches to the header of theloop.Part of the upstreaming effort to move LLVM Flang from fir-dev branch ofhttps://github.com/flang-compiler/f18-llvm-project to the LLVM Project.Reviewed By: awarzynskiDifferential Revision: https://reviews.llvm.org/D124837Co-authored-by: Val Donaldson <vdonaldson@nvidia.com>Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>Co-authored-by: Jean Perier <jperier@nvidia.com>Co-authored-by: Peter Klausler <pklausler@nvidia.com> List of files: /llvm-project-15.0.7/flang/test/Lower/do_loop_unstructured.f90 Fri, 06 May 2022 09:09:01 +0000 Kiran Chandramohan <kiran.chandramohan@arm.com>