From c400670bf1f7fce0ef09aa649c6d7863cf39fea6 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Thu, 11 Nov 2010 00:19:20 +0000 Subject: Insert two blank SlotIndexes between basic blocks instead of just one. This is the first small step towards using closed intervals for liveness instead of the half-open intervals we're using now. We want to be able to distinguish between a SlotIndex that represents a variable being live-out of a basic block, and an index representing a variable live-in to its successor. That requires two separate indexes between blocks. One for live-outs and one for live-ins. With this change, getMBBEndIdx(MBB).getPrevSlot() becomes stable so it stays greater than any instructions inserted at the end of MBB. llvm-svn: 118747 --- llvm/lib/CodeGen/SlotIndexes.cpp | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'llvm/lib/CodeGen/SlotIndexes.cpp') diff --git a/llvm/lib/CodeGen/SlotIndexes.cpp b/llvm/lib/CodeGen/SlotIndexes.cpp index adab9ff3a5a..277cce3db88 100644 --- a/llvm/lib/CodeGen/SlotIndexes.cpp +++ b/llvm/lib/CodeGen/SlotIndexes.cpp @@ -127,8 +127,12 @@ bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) { index += (Slots + 1) * SlotIndex::NUM; } - // One blank instruction at the end. - push_back(createEntry(0, index)); + // We insert two blank instructions between basic blocks. + // One to represent live-out registers and one to represent live-ins. + push_back(createEntry(0, index)); + index += SlotIndex::NUM; + + push_back(createEntry(0, index)); SlotIndex blockEndIndex(back(), SlotIndex::LOAD); mbb2IdxMap.insert( -- cgit v1.2.3