From 27cb347d0e765175efb2c4d388bcbba84cf1b95e Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Tue, 2 Oct 2012 21:46:39 +0000 Subject: Make sure the whole live range is covered when values are pruned twice. JoinVals::pruneValues() calls LIS->pruneValue() to avoid conflicts when overlapping two different values. This produces a set of live range end points that are used to reconstruct the live range (with SSA update) after joining the two registers. When a value is pruned twice, the set of end points was insufficient: v1 = DEF v1 = REPLACE1 v1 = REPLACE2 KILL v1 The end point at KILL would only reconstruct the live range from REPLACE2 to KILL, leaving the range REPLACE1-REPLACE2 dead. Add REPLACE2 as an end point in this case so the full live range is reconstructed. This fixes PR13999. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165056 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/RegisterCoalescer.cpp | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'lib/CodeGen') diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp index f45072f1ac..ad1f5f4f12 100644 --- a/lib/CodeGen/RegisterCoalescer.cpp +++ b/lib/CodeGen/RegisterCoalescer.cpp @@ -1733,11 +1733,15 @@ void JoinVals::pruneValues(JoinVals &Other, // This value takes precedence over the value in Other.LI. LIS->pruneValue(&Other.LI, Def, &EndPoints); // Remove flags. This def is now a partial redef. - if (!Def.isBlock()) + if (!Def.isBlock()) { for (MIOperands MO(Indexes->getInstructionFromIndex(Def)); MO.isValid(); ++MO) if (MO->isReg() && MO->isDef() && MO->getReg() == LI.reg) MO->setIsUndef(false); + // This value will reach instructions below, but we need to make sure + // the live range also reaches the instruction at Def. + EndPoints.push_back(Def); + } DEBUG(dbgs() << "\t\tpruned " << PrintReg(Other.LI.reg) << " at " << Def << ": " << Other.LI << '\n'); break; -- cgit v1.2.3-70-g09d2