Florian Hahn 5f3b78720d [LCSSA] Skip blocks in sub-loops when scanning for uses. ... Summary: Scanning blocks in sub-loops for uses is unnecessary, as they were already handled while dealing with the containing sub-loop. This speeds up LCSSA for highly nested loops. For the test case in PR37202, it halves the time spent in LCSSA. In cases were we won't be able to skip any blocks, the additional lookup should be negligible. Time-passes without this patch for test case from PR37202: Total Execution Time: 48.5505 seconds (48.5511 wall clock) ---User Time--- --System Time-- --User+System-- ---Wall Time--- --- Name --- 10.0822 ( 21.0%) 0.1406 ( 27.0%) 10.2228 ( 21.1%) 10.2228 ( 21.1%) Loop-Closed SSA Form Pass 10.0417 ( 20.9%) 0.1467 ( 28.2%) 10.1884 ( 21.0%) 10.1890 ( 21.0%) Loop-Closed SSA Form Pass #2 4.2703 ( 8.9%) 0.0040 ( 0.8%) 4.2742 ( 8.8%) 4.2742 ( 8.8%) Unswitch loops 2.7376 ( 5.7%) 0.0229 ( 4.4%) 2.7605 ( 5.7%) 2.7611 ( 5.7%) Loop-Closed SSA Form Pass #5 2.7332 ( 5.7%) 0.0214 ( 4.1%) 2.7546 ( 5.7%) 2.7546 ( 5.7%) Loop-Closed SSA Form Pass #3 2.7088 ( 5.6%) 0.0230 ( 4.4%) 2.7319 ( 5.6%) 2.7324 ( 5.6%) Loop-Closed SSA Form Pass #4 2.6855 ( 5.6%) 0.0236 ( 4.5%) 2.7091 ( 5.6%) 2.7090 ( 5.6%) Loop-Closed SSA Form Pass #6 2.1648 ( 4.5%) 0.0018 ( 0.4%) 2.1666 ( 4.5%) 2.1664 ( 4.5%) Unroll loops 1.8371 ( 3.8%) 0.0009 ( 0.2%) 1.8379 ( 3.8%) 1.8380 ( 3.8%) Value Propagation 1.8149 ( 3.8%) 0.0021 ( 0.4%) 1.8170 ( 3.7%) 1.8169 ( 3.7%) Loop Invariant Code Motion 1.6755 ( 3.5%) 0.0226 ( 4.3%) 1.6981 ( 3.5%) 1.6980 ( 3.5%) Loop-Closed SSA Form Pass #7 Time-passes with this patch Total Execution Time: 29.9285 seconds (29.9276 wall clock) ---User Time--- --System Time-- --User+System-- ---Wall Time--- --- Name --- 5.2786 ( 17.7%) 0.0021 ( 1.2%) 5.2806 ( 17.6%) 5.2808 ( 17.6%) Unswitch loops 4.3739 ( 14.7%) 0.0303 ( 18.1%) 4.4042 ( 14.7%) 4.4042 ( 14.7%) Loop-Closed SSA Form Pass 4.2658 ( 14.3%) 0.0192 ( 11.5%) 4.2850 ( 14.3%) 4.2851 ( 14.3%) Loop-Closed SSA Form Pass #2 2.2307 ( 7.5%) 0.0013 ( 0.8%) 2.2320 ( 7.5%) 2.2318 ( 7.5%) Loop Invariant Code Motion 2.0888 ( 7.0%) 0.0012 ( 0.7%) 2.0900 ( 7.0%) 2.0897 ( 7.0%) Unroll loops 1.6761 ( 5.6%) 0.0013 ( 0.8%) 1.6774 ( 5.6%) 1.6774 ( 5.6%) Value Propagation 1.3686 ( 4.6%) 0.0029 ( 1.8%) 1.3716 ( 4.6%) 1.3714 ( 4.6%) Induction Variable Simplification 1.1457 ( 3.8%) 0.0010 ( 0.6%) 1.1468 ( 3.8%) 1.1468 ( 3.8%) Loop-Closed SSA Form Pass #4 1.1384 ( 3.8%) 0.0005 ( 0.3%) 1.1389 ( 3.8%) 1.1389 ( 3.8%) Loop-Closed SSA Form Pass #6 1.1360 ( 3.8%) 0.0027 ( 1.6%) 1.1387 ( 3.8%) 1.1387 ( 3.8%) Loop-Closed SSA Form Pass #5 1.1331 ( 3.8%) 0.0010 ( 0.6%) 1.1341 ( 3.8%) 1.1340 ( 3.8%) Loop-Closed SSA Form Pass #3 Reviewers: davide, efriedma, mzolotukhin Reviewed By: davide, efriedma Subscribers: hiraditya, dmgreen, llvm-commits Differential Revision: https://reviews.llvm.org/D56848 llvm-svn: 351567		2019-01-18 17:36:22 +00:00
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llvm	[LCSSA] Skip blocks in sub-loops when scanning for uses.	2019-01-18 17:36:22 +00:00
llvm-c	[opaque pointer types] Update GetElementPtr creation APIs to	2019-01-14 21:39:35 +00:00