On Mon, May 9, 2016 at 10:46 AM, Richard Biener <richard.guent...@gmail.com> wrote: > On Fri, May 6, 2016 at 11:19 AM, Martin Liška <mli...@suse.cz> wrote: >> Hi. >> >> Honza asked me to explain the change more verbosely. >> The patch simplify enhances verbose dump of IVOPTS so that >> # of iterations is printed. Apart from that it also prints >> invariant expression that are used during the algorithm which >> considers a set of candidates which is improved. >> >> Main motivation for doing this was that sometimes the optimization >> considers a constant integer as invariant expression (Bin Cheng >> is working on removal of these) and that both IVs and IE are considered >> by the cost model to occupy a register. Which is not ideal and >> it sometimes tend to introduce more IVs that one would expect. >> >> === New format ===: >> Improved to: >> cost: 27 (complexity 2) >> cand_cost: 11 >> cand_group_cost: 10 (complexity 2) >> candidates: 3, 5 >> group:0 --> iv_cand:5, cost=(2,0) >> group:1 --> iv_cand:5, cost=(4,1) >> group:2 --> iv_cand:5, cost=(4,1) >> group:3 --> iv_cand:3, cost=(0,0) >> group:4 --> iv_cand:3, cost=(0,0) >> invariants 1, 6 >> used invariant expressions: >> inv_expr:3: ((sizetype) _976 - (sizetype) _922) * 4 >> inv_expr:6: ((sizetype) _1335 - (sizetype) _922) * 4 >> >> >> Original cost 27 (complexity 2) >> >> Final cost 27 (complexity 2) >> >> Selected IV set for loop 96 at original.f90:820, 5 avg niters, 2 >> expressions, 2 IVs: >> >> === Before ===: >> >> Improved to: >> cost: 27 (complexity 2) >> cand_cost: 11 >> cand_group_cost: 10 (complexity 2) >> candidates: 3, 5 >> group:0 --> iv_cand:5, cost=(2,0) >> group:1 --> iv_cand:5, cost=(4,1) >> group:2 --> iv_cand:5, cost=(4,1) >> group:3 --> iv_cand:3, cost=(0,0) >> group:4 --> iv_cand:3, cost=(0,0) >> invariants 1, 6 >> >> Original cost 27 (complexity 2) >> >> Final cost 27 (complexity 2) >> >> Selected IV set for loop 96 at original.f90:820, 2 IVs: > > But it slows donw compile-time just for enhanced dump files. Can you > make the new > hash-map conditional on dumping? Hi,
Another way is to remove the use of id for struct iv_inv_expr_ent once for all. We can change iv_ca.used_inv_expr and cost_pair.inv_expr_id to pointers, and rename iv_inv_expr_ent.id to count and use this to record reference number in iv_ca. This if-statement on dump_file can be saved. Also I think it simplifies current code a bit. For now, there are id <-> struct maps for different structures in IVOPT which make it not straightforward. Thanks, bin > > Richard. > >> >> Martin
