From 1e8e72d72a71ec3fb6c81bd35a34261f34436900 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Thu, 11 Nov 2010 00:19:20 +0000 Subject: [PATCH] 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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118747 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/SlotIndexes.h | 2 ++ lib/CodeGen/SlotIndexes.cpp | 8 ++++++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/include/llvm/CodeGen/SlotIndexes.h b/include/llvm/CodeGen/SlotIndexes.h index d207923099f..c8f26544f0d 100644 --- a/include/llvm/CodeGen/SlotIndexes.h +++ b/include/llvm/CodeGen/SlotIndexes.h @@ -738,6 +738,7 @@ namespace llvm { MachineFunction::iterator nextMBB = llvm::next(MachineFunction::iterator(mbb)); IndexListEntry *startEntry = createEntry(0, 0); + IndexListEntry *stopEntry = createEntry(0, 0); IndexListEntry *nextEntry = 0; if (nextMBB == mbb->getParent()->end()) { @@ -747,6 +748,7 @@ namespace llvm { } insert(nextEntry, startEntry); + insert(nextEntry, stopEntry); SlotIndex startIdx(startEntry, SlotIndex::LOAD); SlotIndex endIdx(nextEntry, SlotIndex::LOAD); diff --git a/lib/CodeGen/SlotIndexes.cpp b/lib/CodeGen/SlotIndexes.cpp index adab9ff3a5a..277cce3db88 100644 --- a/lib/CodeGen/SlotIndexes.cpp +++ b/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(