3 Commits

Author	SHA1	Message	Date
Sam Tebbs	1a497ae9b8	[ARM][Block placement] Check the predecessor exists before processing it ... Not all machine loops will have a predecessor. so the pass needs to check it before continuing. Reviewed By: dmgreen Differential Revision: https://reviews.llvm.org/D94780	2021-01-15 15:45:13 +00:00
Sam Tebbs	5e4480b6c0	[ARM] Don't run the block placement pass at O0 ... The block placement pass shouldn't run unless optimisations are enabled. Differential Revision: https://reviews.llvm.org/D94691	2021-01-15 13:59:29 +00:00
Sam Tebbs	60fda8ebb6	[ARM] Add a pass that re-arranges blocks when there is a backwards WLS branch ... Blocks can be laid out such that a t2WhileLoopStart branches backwards. This is forbidden by the architecture and so it fails to be converted into a low-overhead loop. This new pass checks for these cases and moves the target block, fixing any fall-through that would then be broken. Differential Revision: https://reviews.llvm.org/D92385	2021-01-13 17:23:00 +00:00