From 84315f03cb6127ac92a5b02239c6edc2a347069a Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Wed, 25 Jul 2012 17:15:15 +0000
Subject: Preserve 2-addr constraints in ConnectedVNInfoEqClasses.

When a live range splits into multiple connected components, we would
arbitrarily assign <undef> uses to component 0. This is wrong when the
use is tied to a def that gets assigned to a different component:

  %vreg69<def> = ADD8ri %vreg68<undef>, 1

The use and def must get the same virtual register.

Fix this by assigning <undef> uses to the same component as the value
defined by the instruction, if any:

  %vreg69<def> = ADD8ri %vreg69<undef>, 1

This fixes PR13402. The PR has a test case which I am not including
because it is unlikely to keep exposing this behavior in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160739 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/LiveInterval.cpp | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

(limited to 'lib/CodeGen/LiveInterval.cpp')

diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index 01077db..b6d1e5f 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -827,14 +827,11 @@ void ConnectedVNInfoEqClasses::Distribute(LiveInterval *LIV[],
     MachineOperand &MO = RI.getOperand();
     MachineInstr *MI = MO.getParent();
     ++RI;
-    if (MO.isUse() && MO.isUndef())
-      continue;
     // DBG_VALUE instructions should have been eliminated earlier.
-    SlotIndex Idx = LIS.getInstructionIndex(MI);
-    Idx = Idx.getRegSlot(MO.isUse());
-    const VNInfo *VNI = LI.getVNInfoAt(Idx);
-    // FIXME: We should be able to assert(VNI) here, but the coalescer leaves
-    // dangling defs around.
+    LiveRangeQuery LRQ(LI, LIS.getInstructionIndex(MI));
+    const VNInfo *VNI = MO.readsReg() ? LRQ.valueIn() : LRQ.valueDefined();
+    // In the case of an <undef> use that isn't tied to any def, VNI will be
+    // NULL. If the use is tied to a def, VNI will be the defined value.
     if (!VNI)
       continue;
     MO.setReg(LIV[getEqClass(VNI)]->reg);
-- 
cgit v1.1


From bf60aa9db5953dd99c561dfa9323b1e3293a5a85 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Fri, 3 Aug 2012 20:19:44 +0000
Subject: Eliminate the VNInfo::hasPHIKill() flag.

The only real user of the flag was removeCopyByCommutingDef(), and it
has been switched to LiveIntervals::hasPHIKill().

All the code changed by this patch was only concerned with computing and
propagating the flag.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161255 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/LiveInterval.cpp | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

(limited to 'lib/CodeGen/LiveInterval.cpp')

diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index b6d1e5f..db00d2e 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -737,9 +737,7 @@ void LiveInterval::print(raw_ostream &OS) const {
       } else {
         OS << vni->def;
         if (vni->isPHIDef())
-          OS << "-phidef";
-        if (vni->hasPHIKill())
-          OS << "-phikill";
+          OS << "-phi";
       }
     }
   }
-- 
cgit v1.1


From b2beac2b9671f7d9773329d62c2821c8ac449ac5 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Fri, 3 Aug 2012 20:59:32 +0000
Subject: Completely eliminate VNInfo flags.

The 'unused' state of a value number can be represented as an invalid
def SlotIndex. This also exposed code that shouldn't have been looking
at unused value VNInfos.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161258 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/LiveInterval.cpp | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

(limited to 'lib/CodeGen/LiveInterval.cpp')

diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index db00d2e..0a795e6 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -160,7 +160,7 @@ void LiveInterval::markValNoForDeletion(VNInfo *ValNo) {
       valnos.pop_back();
     } while (!valnos.empty() && valnos.back()->isUnused());
   } else {
-    ValNo->setIsUnused(true);
+    ValNo->markUnused();
   }
 }
 
@@ -667,9 +667,6 @@ VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) {
     }
   }
 
-  // Merge the relevant flags.
-  V2->mergeFlags(V1);
-
   // Now that V1 is dead, remove it.
   markValNoForDeletion(V1);
 
-- 
cgit v1.1