From 7c2e4a8715836a44e82ac6c7370826519ccdfddb Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Tue, 16 Nov 2010 00:40:59 +0000
Subject: [PATCH] Fix PR8612 in the standard spiller, take two.
The live range of a register defined by an early clobber starts at the use slot,
not the def slot.
Except when it is an early clobber tied to a use operand. Then it starts at the
def slot like a standard def.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119305 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/CodeGen/LiveIntervalAnalysis.cpp | 9 ++++++++-
test/CodeGen/ARM/2010-11-15-SpillEarlyClobber.ll | 1 +
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index aa2f9658874..9b42012979f 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -1136,11 +1136,14 @@ rewriteInstructionForSpills(const LiveInterval &li, const VNInfo *VNI,
rewriteImplicitOps(li, MI, NewVReg, vrm);
// Reuse NewVReg for other reads.
+ bool HasEarlyClobber = false;
for (unsigned j = 0, e = Ops.size(); j != e; ++j) {
MachineOperand &mopj = MI->getOperand(Ops[j]);
mopj.setReg(NewVReg);
if (mopj.isImplicit())
rewriteImplicitOps(li, MI, NewVReg, vrm);
+ if (mopj.isEarlyClobber())
+ HasEarlyClobber = true;
}
if (CreatedNewVReg) {
@@ -1199,7 +1202,11 @@ rewriteInstructionForSpills(const LiveInterval &li, const VNInfo *VNI,
}
}
if (HasDef) {
- LiveRange LR(index.getDefIndex(), index.getStoreIndex(),
+ // An early clobber starts at the use slot, except for an early clobber
+ // tied to a use operand (yes, that is a thing).
+ LiveRange LR(HasEarlyClobber && !HasUse ?
+ index.getUseIndex() : index.getDefIndex(),
+ index.getStoreIndex(),
nI.getNextValue(SlotIndex(), 0, VNInfoAllocator));
DEBUG(dbgs() << " +" << LR);
nI.addRange(LR);
diff --git a/test/CodeGen/ARM/2010-11-15-SpillEarlyClobber.ll b/test/CodeGen/ARM/2010-11-15-SpillEarlyClobber.ll
index 046016aa3f3..04220949027 100644
--- a/test/CodeGen/ARM/2010-11-15-SpillEarlyClobber.ll
+++ b/test/CodeGen/ARM/2010-11-15-SpillEarlyClobber.ll
@@ -1,3 +1,4 @@
+; RUN: llc < %s -verify-machineinstrs -spiller=standard
; RUN: llc < %s -verify-machineinstrs -spiller=inline
; PR8612
;