From 731b04ca43dd43df65c02e1beeb386d25cf32cf7 Mon Sep 17 00:00:00 2001 From: Haicheng Wu Date: Wed, 23 Nov 2016 19:39:26 +0000 Subject: [PATCH] [LoopUnroll] Move code to exit early. NFC. Just to save some compilation time. Differential Revision: https://reviews.llvm.org/D26784 llvm-svn: 287800 --- llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp index 7b154be..2408d42 100644 --- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp +++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp @@ -948,7 +948,11 @@ static bool tryToUnrollLoop(Loop *L, DominatorTree &DT, LoopInfo *LI, Optional ProvidedUpperBound) { DEBUG(dbgs() << "Loop Unroll: F[" << L->getHeader()->getParent()->getName() << "] Loop %" << L->getHeader()->getName() << "\n"); - if (HasUnrollDisablePragma(L)) { + if (HasUnrollDisablePragma(L)) + return false; + if (!L->isLoopSimplifyForm()) { + DEBUG( + dbgs() << " Not unrolling loop which is not in loop-simplify form.\n"); return false; } @@ -958,6 +962,9 @@ static bool tryToUnrollLoop(Loop *L, DominatorTree &DT, LoopInfo *LI, TargetTransformInfo::UnrollingPreferences UP = gatherUnrollingPreferences( L, TTI, ProvidedThreshold, ProvidedCount, ProvidedAllowPartial, ProvidedRuntime, ProvidedUpperBound); + // Exit early if unrolling is disabled. + if (UP.Threshold == 0 && (!UP.Partial || UP.PartialThreshold == 0)) + return false; unsigned LoopSize = ApproximateLoopSize( L, NumInlineCandidates, NotDuplicatable, Convergent, TTI, &AC, UP.BEInsns); DEBUG(dbgs() << " Loop Size = " << LoopSize << "\n"); @@ -970,11 +977,6 @@ static bool tryToUnrollLoop(Loop *L, DominatorTree &DT, LoopInfo *LI, DEBUG(dbgs() << " Not unrolling loop with inlinable calls.\n"); return false; } - if (!L->isLoopSimplifyForm()) { - DEBUG( - dbgs() << " Not unrolling loop which is not in loop-simplify form.\n"); - return false; - } // Find trip count and trip multiple if count is not available unsigned TripCount = 0; @@ -991,10 +993,6 @@ static bool tryToUnrollLoop(Loop *L, DominatorTree &DT, LoopInfo *LI, TripMultiple = SE->getSmallConstantTripMultiple(L, ExitingBlock); } - // Exit early if unrolling is disabled. - if (UP.Threshold == 0 && (!UP.Partial || UP.PartialThreshold == 0)) - return false; - // If the loop contains a convergent operation, the prelude we'd add // to do the first few instructions before we hit the unrolled loop // is unsafe -- it adds a control-flow dependency to the convergent -- 2.7.4