Author: hans Date: Wed Aug 28 02:55:07 2019 New Revision: 370182 URL: http://llvm.org/viewvc/llvm-project?rev=370182&view=rev Log: Merging r369886: ------------------------------------------------------------------------ r369886 | bjope | 2019-08-26 11:29:53 +0200 (Mon, 26 Aug 2019) | 23 lines
[LoopUnroll] Handle certain PHIs in full unrolling properly Summary: When reconstructing the CFG of the loop after unrolling, LoopUnroll could in some cases remove the phi operands of loop-carried values instead of preserving them, resulting in undef phi values after loop unrolling. When doing this reconstruction, avoid removing incoming phi values for phis in the successor blocks if the successor is the block we are jumping to anyway. Patch-by: ebevhan Reviewers: fhahn, efriedma Reviewed By: fhahn Subscribers: bjope, lebedev.ri, zzheng, dmgreen, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66334 ------------------------------------------------------------------------ Added: llvm/branches/release_90/test/Transforms/LoopUnroll/unroll-header-exiting-with-phis.ll - copied unchanged from r369886, llvm/trunk/test/Transforms/LoopUnroll/unroll-header-exiting-with-phis.ll Modified: llvm/branches/release_90/ (props changed) llvm/branches/release_90/lib/Transforms/Utils/LoopUnroll.cpp Propchange: llvm/branches/release_90/ ------------------------------------------------------------------------------ --- svn:mergeinfo (original) +++ svn:mergeinfo Wed Aug 28 02:55:07 2019 @@ -1,3 +1,3 @@ /llvm/branches/Apple/Pertwee:110850,110961 /llvm/branches/type-system-rewrite:133420-134817 -/llvm/trunk:155241,366431,366447,366481,366487,366527,366570,366660,366868,366925,367019,367030,367062,367084,367124,367215,367292,367304,367306,367314,367340-367341,367394,367396,367398,367403,367412,367417,367429,367580,367662,367750,367753,367846-367847,367898,367941,368004,368230,368300,368315,368324,368477-368478,368517-368519,368554,368572,368873,369011,369026,369084,369095,369097,369168,369199,369426,369443,370036,370176 +/llvm/trunk:155241,366431,366447,366481,366487,366527,366570,366660,366868,366925,367019,367030,367062,367084,367124,367215,367292,367304,367306,367314,367340-367341,367394,367396,367398,367403,367412,367417,367429,367580,367662,367750,367753,367846-367847,367898,367941,368004,368230,368300,368315,368324,368477-368478,368517-368519,368554,368572,368873,369011,369026,369084,369095,369097,369168,369199,369426,369443,369886,370036,370176 Modified: llvm/branches/release_90/lib/Transforms/Utils/LoopUnroll.cpp URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_90/lib/Transforms/Utils/LoopUnroll.cpp?rev=370182&r1=370181&r2=370182&view=diff ============================================================================== --- llvm/branches/release_90/lib/Transforms/Utils/LoopUnroll.cpp (original) +++ llvm/branches/release_90/lib/Transforms/Utils/LoopUnroll.cpp Wed Aug 28 02:55:07 2019 @@ -711,7 +711,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop * auto setDest = [LoopExit, ContinueOnTrue](BasicBlock *Src, BasicBlock *Dest, ArrayRef<BasicBlock *> NextBlocks, - BasicBlock *CurrentHeader, + BasicBlock *BlockInLoop, bool NeedConditional) { auto *Term = cast<BranchInst>(Src->getTerminator()); if (NeedConditional) { @@ -723,7 +723,9 @@ LoopUnrollResult llvm::UnrollLoop(Loop * if (Dest != LoopExit) { BasicBlock *BB = Src; for (BasicBlock *Succ : successors(BB)) { - if (Succ == CurrentHeader) + // Preserve the incoming value from BB if we are jumping to the block + // in the current loop. + if (Succ == BlockInLoop) continue; for (PHINode &Phi : Succ->phis()) Phi.removeIncomingValue(BB, false); @@ -794,7 +796,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop * // unconditional branch for some iterations. NeedConditional = false; - setDest(Headers[i], Dest, Headers, Headers[i], NeedConditional); + setDest(Headers[i], Dest, Headers, HeaderSucc[i], NeedConditional); } // Set up latches to branch to the new header in the unrolled iterations or _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
