From 7df1db57b3ae35afcc1df648f1446b7c7b60993b Mon Sep 17 00:00:00 2001 From: "Duncan P. N. Exon Smith" Date: Fri, 1 Aug 2014 22:50:04 +0000 Subject: [PATCH] UseListOrder: Guarantee that shuffles change use-list order Change shuffleUseLists() always to change use-list order by rejecting orders that have no changes. This is part of PR5680. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214584 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/IR/UseListOrder.cpp | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/lib/IR/UseListOrder.cpp b/lib/IR/UseListOrder.cpp index 7d845d1185b..0b0ad922312 100644 --- a/lib/IR/UseListOrder.cpp +++ b/lib/IR/UseListOrder.cpp @@ -63,17 +63,20 @@ static void shuffleValueUseLists(Value *V, std::minstd_rand0 &Gen, DEBUG(dbgs() << "V = "; V->dump()); std::uniform_int_distribution Dist(10, 99); SmallDenseMap Order; - for (const Use &U : V->uses()) { - auto I = Dist(Gen); - Order[&U] = I; - DEBUG(dbgs() << " - order: " << I << ", op = " << U.getOperandNo() - << ", U = "; - U.getUser()->dump()); - } + auto compareUses = + [&Order](const Use &L, const Use &R) { return Order[&L] < Order[&R]; }; + do { + for (const Use &U : V->uses()) { + auto I = Dist(Gen); + Order[&U] = I; + DEBUG(dbgs() << " - order: " << I << ", op = " << U.getOperandNo() + << ", U = "; + U.getUser()->dump()); + } + } while (std::is_sorted(V->use_begin(), V->use_end(), compareUses)); DEBUG(dbgs() << " => shuffle\n"); - V->sortUseList( - [&Order](const Use &L, const Use &R) { return Order[&L] < Order[&R]; }); + V->sortUseList(compareUses); DEBUG({ for (const Use &U : V->uses()) {