http://llvm.org https://git.amat.us/llvm/atom/test/Transforms/LoopRotate?h=release_29 2011-02-14T23:03:23Z 2011-02-14T23:03:23Z Devang Patel dpatel@apple.com 2011-02-14T23:03:23Z urn:sha1:3fc178ffdad0c3359f8e4bad084556a3054e1ed2 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125529 91177308-0d34-0410-b5e6-96231b3b80d8 2011-01-11T07:50:07Z Chris Lattner sabre@nondot.org 2011-01-11T07:50:07Z urn:sha1:86099ba2b5cf27127e0f5b7a1289b6d076687960 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123220 91177308-0d34-0410-b5e6-96231b3b80d8 2011-01-11T07:47:59Z Chris Lattner sabre@nondot.org 2011-01-11T07:47:59Z urn:sha1:93767fdb61dfff6ab13056b2a73209998ae4e786 neccesarily an uncond branch to the header. This fixes PR8955 (the assertion tripping). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123219 91177308-0d34-0410-b5e6-96231b3b80d8 2011-01-08T19:59:06Z Chris Lattner sabre@nondot.org 2011-01-08T19:59:06Z urn:sha1:5d37370a6ff255293d0b97abf9e8b3d46ed17238 to be foldable into an uncond branch. When this happens, we can make a much simpler CFG for the loop, which is important for nested loop cases where we want the outer loop to be aggressively optimized. Handle this case more aggressively. For example, previously on phi-duplicate.ll we would get this: define void @test(i32 %N, double* %G) nounwind ssp { entry: %cmp1 = icmp slt i64 1, 1000 br i1 %cmp1, label %bb.nph, label %for.end bb.nph: ; preds = %entry br label %for.body for.body: ; preds = %bb.nph, %for.cond %j.02 = phi i64 [ 1, %bb.nph ], [ %inc, %for.cond ] %arrayidx = getelementptr inbounds double* %G, i64 %j.02 %tmp3 = load double* %arrayidx %sub = sub i64 %j.02, 1 %arrayidx6 = getelementptr inbounds double* %G, i64 %sub %tmp7 = load double* %arrayidx6 %add = fadd double %tmp3, %tmp7 %arrayidx10 = getelementptr inbounds double* %G, i64 %j.02 store double %add, double* %arrayidx10 %inc = add nsw i64 %j.02, 1 br label %for.cond for.cond: ; preds = %for.body %cmp = icmp slt i64 %inc, 1000 br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge for.cond.for.end_crit_edge: ; preds = %for.cond br label %for.end for.end: ; preds = %for.cond.for.end_crit_edge, %entry ret void } Now we get the much nicer: define void @test(i32 %N, double* %G) nounwind ssp { entry: br label %for.body for.body: ; preds = %entry, %for.body %j.01 = phi i64 [ 1, %entry ], [ %inc, %for.body ] %arrayidx = getelementptr inbounds double* %G, i64 %j.01 %tmp3 = load double* %arrayidx %sub = sub i64 %j.01, 1 %arrayidx6 = getelementptr inbounds double* %G, i64 %sub %tmp7 = load double* %arrayidx6 %add = fadd double %tmp3, %tmp7 %arrayidx10 = getelementptr inbounds double* %G, i64 %j.01 store double %add, double* %arrayidx10 %inc = add nsw i64 %j.01, 1 %cmp = icmp slt i64 %inc, 1000 br i1 %cmp, label %for.body, label %for.end for.end: ; preds = %for.body ret void } With all of these recent changes, we are now able to compile: void foo(char *X) { for (int i = 0; i != 100; ++i) for (int j = 0; j != 100; ++j) X[j+i*100] = 0; } into a single memset of 10000 bytes. This series of changes should also be helpful for other nested loop scenarios as well. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123079 91177308-0d34-0410-b5e6-96231b3b80d8 2011-01-08T18:52:51Z Chris Lattner sabre@nondot.org 2011-01-08T18:52:51Z urn:sha1:0e4a1543aba1364fe4a1eacee46b6d08d4611506 1. Rip out LoopRotate's domfrontier updating code. It isn't needed now that LICM doesn't use DF and it is super complex and gross. 2. Make DomTree updating code a lot simpler and faster. The old loop over all the blocks was just to find a block?? 3. Change the code that inserts the new preheader to just use SplitCriticalEdge instead of doing an overcomplex reimplementation of it. No behavior change, except for the name of the inserted preheader. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123072 91177308-0d34-0410-b5e6-96231b3b80d8 2011-01-08T08:24:46Z Chris Lattner sabre@nondot.org 2011-01-08T08:24:46Z urn:sha1:d9ec3572f3d0997348361334446f942194522127 them into the loop preheader, eliminating silly instructions like "icmp i32 0, 100" in fixed tripcount loops. This also better exposes the bigger problem with loop rotate that I'd like to fix: once this has been folded, the duplicated conditional branch *often* turns into an uncond branch. Not aggressively handling this is pessimizing later loop optimizations somethin' fierce by making "dominates all exit blocks" checks fail. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123060 91177308-0d34-0410-b5e6-96231b3b80d8 2010-09-06T01:10:22Z Chris Lattner sabre@nondot.org 2010-09-06T01:10:22Z urn:sha1:50fb46983ccae116bdbda64471f4861108766135 in the duplicated block instead of duplicating them. Duplicating them into the end of the loop and the preheader means that we got a phi node in the header of the loop, which prevented LICM from hoisting them. GVN would usually come around later and merge the duplicated instructions so we'd get reasonable output... except that anything dependent on the shoulda-been-hoisted value can't be hoisted. In PR5319 (which this fixes), a memory value didn't get promoted. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113134 91177308-0d34-0410-b5e6-96231b3b80d8 2010-08-17T17:39:21Z Dan Gohman gohman@apple.com 2010-08-17T17:39:21Z urn:sha1:fc8042a1225790b3a6de434546623babea08496f loop, making the resulting loop significantly less ugly. Also, zap its trivial PHI nodes, since it's easy. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111255 91177308-0d34-0410-b5e6-96231b3b80d8 2010-06-26T20:05:06Z Benjamin Kramer benny.kra@googlemail.com 2010-06-26T20:05:06Z urn:sha1:a2938e7e5f7f16b4593b6ddc0eaf14bd6ed620de git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106954 91177308-0d34-0410-b5e6-96231b3b80d8 2010-01-05T17:55:26Z Dan Gohman gohman@apple.com 2010-01-05T17:55:26Z urn:sha1:aceba31b7a04fd28680209b2677915378877bc13 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92740 91177308-0d34-0410-b5e6-96231b3b80d8