3 Commits

Author	SHA1	Message	Date
Toomas Remmelg	1dc2458060	Add a loop fusion pass. ... This pass will look for adjacent loops that are compatible and legal to be fused. Loops are compatible if: - they both have one induction variable - they have the same upper and lower bounds - same initial value - same condition - they have the same update step - they are adjacent - there are no break/continue in either of them Fusion is legal if: - fused loops do not have any dependencies with dependence distance greater than 0 that did not exist in the original loops. - there are no function calls in the loops (could have side-effects) - there are no barriers in the loops It will fuse all such loops as long as the number of registers used for the fused loop stays under the threshold defined by max_registers_per_loop.	2018-05-01 15:40:37 -04:00
Victor Lomuller	10e5d7cf13	Add a loop peeling pass. ... For each loop in a function, the pass walks the loops from inner to outer most loop and tries to peel loop for which a certain amount of iteration can be done before or after the loop. To limit code growth, peeling will not happen if the growth in code size goes above a configurable threshold.	2018-04-11 15:41:29 +01:00
Stephen McGroarty	ad7e4b8401	Initial patch for scalar evolution analysis ... This patch adds support for the analysis of scalars in loops. It works by traversing the defuse chain to build a DAG of scalar operations and then simplifies the DAG by folding constants and grouping like terms. It represents induction variables as recurrent expressions with respect to a given loop and can simplify DAGs containing recurrent expression by rewritting the entire DAG to be a recurrent expression with respect to the same loop.	2018-03-28 16:34:23 -04:00