http://llvm.org https://git.amat.us/llvm/atom/test/Transforms/LoopStrengthReduce?h=release_25 2009-02-17T19:32:45Z 2009-02-17T19:32:45Z Tanya Lattner tonic@nondot.org 2009-02-17T19:32:45Z urn:sha1:3bf2b5ea6fe27c2528354f40dab3ed39bdb35f89 Fix pr3571: If stride is a value defined by an instruction, make sure it dominates the loop preheader. When IV users are strength reduced, the stride is inserted into the preheader. It could create a use before def situation. git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_25@64789 91177308-0d34-0410-b5e6-96231b3b80d8 2009-02-14T00:57:30Z Tanya Lattner tonic@nondot.org 2009-02-14T00:57:30Z urn:sha1:67a8eaa03b0a0fb119d7ac94b49969ad8b6ccbe9 Fix PR 3471, and some cleanups. git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_25@64517 91177308-0d34-0410-b5e6-96231b3b80d8 2009-01-14T02:35:31Z Dale Johannesen dalej@apple.com 2009-01-14T02:35:31Z urn:sha1:2f46bb8178e30e3b845859a44b57c048db06ef84 my earlier patch to this file. The issue there was that all uses of an IV inside a loop are actually references to Base[IV*2], and there was one use outside that was the same but LSR didn't see the base or the scaling because it didn't recurse into uses outside the loop; thus, it used base+IV*scale mode inside the loop instead of pulling base out of the loop. This was extra bad because register pressure later forced both base and IV into memory. Doing that recursion, at least enough to figure out addressing modes, is a good idea in general; the change in AddUsersIfInteresting does this. However, there were side effects.... It is also possible for recursing outside the loop to introduce another IV where there was only 1 before (if the refs inside are not scaled and the ref outside is). I don't think this is a common case, but it's in the testsuite. It is right to be very aggressive about getting rid of such introduced IVs (CheckForIVReuse and the handling of nonzero RewriteFactor in StrengthReduceStridedIVUsers). In the testcase in question the new IV produced this way has both a nonconstant stride and a nonzero base, neither of which was handled before. And when inserting new code that feeds into a PHI, it's right to put such code at the original location rather than in the PHI's immediate predecessor(s) when the original location is outside the loop (a case that couldn't happen before) (RewriteInstructionToUseNewBase); better to avoid making multiple copies of it in this case. Also, the mechanism for keeping SCEV's corresponding to GEP's no longer works, as the GEP might change after its SCEV is remembered, invalidating the SCEV, and we might get a bad SCEV value when looking up the GEP again for a later loop. This also couldn't happen before, as we weren't recursing into GEP's outside the loop. Also, when we build an expression that involves a (possibly non-affine) IV from a different loop as well as an IV from the one we're interested in (containsAddRecFromDifferentLoop), don't recurse into that. We can't do much with it and will get in trouble if we try to create new non-affine IVs or something. More testcases are coming. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62212 91177308-0d34-0410-b5e6-96231b3b80d8 2008-09-09T21:41:34Z Devang Patel dpatel@apple.com 2008-09-09T21:41:34Z urn:sha1:a009d2ef54fa8dc1c963ac6612d6c6f0a8d7712e git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56018 91177308-0d34-0410-b5e6-96231b3b80d8 2008-09-09T20:54:34Z Devang Patel dpatel@apple.com 2008-09-09T20:54:34Z urn:sha1:4b3f08bac7def05de67f5c0e9f15c53d0870c7c1 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56011 91177308-0d34-0410-b5e6-96231b3b80d8 2008-09-08T16:24:30Z Devang Patel dpatel@apple.com 2008-09-08T16:24:30Z urn:sha1:ac8ab789ac6de1d4d40cde6e7847c9e21ac31c35 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55914 91177308-0d34-0410-b5e6-96231b3b80d8 2008-09-03T00:10:56Z Devang Patel dpatel@apple.com 2008-09-03T00:10:56Z urn:sha1:a9348dc7acc6f292425721c178311d7b0b5144b6 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55680 91177308-0d34-0410-b5e6-96231b3b80d8 2008-09-02T22:18:08Z Devang Patel dpatel@apple.com 2008-09-02T22:18:08Z urn:sha1:108f92e376fd5f7c7c5c4e22dd10c1a5b279b1e3 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55674 91177308-0d34-0410-b5e6-96231b3b80d8 2008-08-26T17:57:54Z Devang Patel dpatel@apple.com 2008-08-26T17:57:54Z urn:sha1:a0b3909d432e9f2c79aee8ec3133f9b9ec71dc1a git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55374 91177308-0d34-0410-b5e6-96231b3b80d8 2008-08-18T18:29:54Z Bill Wendling isanbard@gmail.com 2008-08-18T18:29:54Z urn:sha1:2dcca3a6d8d23b9ad3481e3a6a4d067a60c31ada git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54929 91177308-0d34-0410-b5e6-96231b3b80d8