Index: lib/CodeGen/PHIElimination.cpp =================================================================== --- lib/CodeGen/PHIElimination.cpp +++ lib/CodeGen/PHIElimination.cpp @@ -573,12 +573,14 @@ // there is a risk it may not be coalesced away. // // If the copy would be a kill, there is no need to split the edge. - if (!isLiveOutPastPHIs(Reg, PreMBB) && !SplitAllCriticalEdges) - continue; - - DEBUG(dbgs() << PrintReg(Reg) << " live-out before critical edge BB#" - << PreMBB->getNumber() << " -> BB#" << MBB.getNumber() - << ": " << *BBI); + // if (!isLiveOutPastPHIs(Reg, PreMBB) && !SplitAllCriticalEdges) + // continue; + bool ShouldSplit = isLiveOutPastPHIs(Reg, PreMBB); + if (ShouldSplit) { + DEBUG(dbgs() << PrintReg(Reg) << " live-out before critical edge BB#" + << PreMBB->getNumber() << " -> BB#" << MBB.getNumber() + << ": " << *BBI); + } // If Reg is not live-in to MBB, it means it must be live-in to some // other PreMBB successor, and we can avoid the interference by splitting @@ -588,7 +590,7 @@ // is likely to be left after coalescing. If we are looking at a loop // exiting edge, split it so we won't insert code in the loop, otherwise // don't bother. - bool ShouldSplit = !isLiveIn(Reg, &MBB) || SplitAllCriticalEdges; + ShouldSplit = ShouldSplit && !isLiveIn(Reg, &MBB); // Check for a loop exiting edge. if (!ShouldSplit && CurLoop != PreLoop) { @@ -603,7 +605,7 @@ // Split unless this edge is entering CurLoop from an outer loop. ShouldSplit = PreLoop && !PreLoop->contains(CurLoop); } - if (!ShouldSplit) + if (!ShouldSplit && !SplitAllCriticalEdges) continue; if (!PreMBB->SplitCriticalEdge(&MBB, this)) { DEBUG(dbgs() << "Failed to split critical edge.\n");