Preventing loop reordering

The no_loop_transform directive or pragma allows you to prevent all loop-reordering transformations on the immediately following loop. The form of this directive and pragma are shown in Table 5-8 “Form of no_loop_transform directive and pragma”.

Use the command-line option +Onoloop_transform (at +O3 and above) to disable loop distribution, loop blocking, loop fusion, loop interchange, loop unroll, and loop unroll and jam at the file level.