From 9ef931e71c06a0390d6387859843be1d6d4daad6 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Fri, 18 Mar 2011 03:06:04 +0000 Subject: [PATCH] Accept instructions that read undefined values. This is not supposed to happen, but I have seen the x86 rematter getting confused when rematerializing partial redefs. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127857 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/LiveIntervalAnalysis.cpp | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp index c47c8397488..d1de6a85398 100644 --- a/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -761,7 +761,15 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, continue; SlotIndex Idx = getInstructionIndex(UseMI).getUseIndex(); VNInfo *VNI = li->getVNInfoAt(Idx); - assert(VNI && "Live interval not live into reading instruction"); + if (!VNI) { + // This shouldn't happen: readsVirtualRegister returns true, but there is + // no live value. It is likely caused by a target getting flags + // wrong. + DEBUG(dbgs() << Idx << '\t' << *UseMI + << "Warning: Instr claims to read non-existent value in " + << *li << '\n'); + continue; + } if (VNI->def == Idx) { // Special case: An early-clobber tied operand reads and writes the // register one slot early. -- 2.34.1