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* Revert "Temporarily Revert "Add basic loop fusion pass.""Eric Christopher2019-04-171-0/+69
| | | | | | | | The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
* Temporarily Revert "Add basic loop fusion pass."Eric Christopher2019-04-171-69/+0
| | | | | | | | As it's causing some bot failures (and per request from kbarton). This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda. llvm-svn: 358546
* [New PM][IRCE] port of Inductive Range Check Elimination pass to the new ↵Fedor Sergeev2018-03-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | pass manager There are two nontrivial details here: * Loop structure update interface is quite different with new pass manager, so the code to add new loops was factored out * BranchProbabilityInfo is not a loop analysis, so it can not be just getResult'ed from within the loop pass. It cant even be queried through getCachedResult as LoopCanonicalization sequence (e.g. LoopSimplify) might invalidate BPI results. Complete solution for BPI will likely take some time to discuss and figure out, so for now this was partially solved by making BPI optional in IRCE (skipping a couple of profitability checks if it is absent). Most of the IRCE tests got their corresponding new-pass-manager variant enabled. Only two of them depend on BPI, both marked with TODO, to be turned on when BPI starts being available for loop passes. Reviewers: chandlerc, mkazantsev, sanjoy, asbirlea Reviewed By: mkazantsev Differential Revision: https://reviews.llvm.org/D43795 llvm-svn: 327619
* [IRCE] Fix intersection between signed and unsigned rangesMax Kazantsev2017-10-251-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | IRCE for unsigned latch conditions was temporarily disabled by rL314881. The motivating example contained an unsigned latch condition and a signed range check. One of the safe iteration ranges was `[1, SINT_MAX + 1]`. Its right border was incorrectly interpreted as a negative value in `IntersectRange` function, this lead to a miscompile under which we deleted a range check without inserting a postloop where it was needed. This patch brings back IRCE for unsigned latch conditions. Now we treat range intersection more carefully. If the latch condition was unsigned, we only try to consider a range check for deletion if: 1. The range check is also unsigned, or 2. Safe iteration range of the range check lies within `[0, SINT_MAX]`. The same is done for signed latch. Values from `[0, SINT_MAX]` are unambiguous, these values are non-negative under any interpretation, and all values of a range intersected with such range are also non-negative. We also use signed/unsigned min/max functions for range intersection depending on type of the latch condition. Differential Revision: https://reviews.llvm.org/D38581 llvm-svn: 316552
* [IRCE] Smarter detection of empty ranges using SCEVMax Kazantsev2017-10-251-0/+69
For a SCEV range, this patch replaces the naive emptiness check for SCEV ranges which looks like `Begin == End` with a SCEV check. The range is guaranteed to be empty of `Begin >= End`. We should filter such ranges out and do not try to perform IRCE for them. For example, we can get such range when intersecting range `[A, B)` and `[C, D)` where `A < B < C < D`. The resulting range is `[max(A, C), min(B, D)) = [C, B)`. This range is empty, but its `Begin` does not match with `End`. Making IRCE for an empty range is basically safe but unprofitable because we never actually get into the main loop where the range checks are supposed to be eliminated. This patch uses SCEV mechanisms to treat loops with proved `Begin >= End` as empty. Differential Revision: https://reviews.llvm.org/D39082 llvm-svn: 316550
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