From 5a4b3d8c8f52ee225ffc65c7d6cebc78b1ec7808 Mon Sep 17 00:00:00 2001
From: Cameron Zwarich <zwarich@apple.com>
Date: Thu, 19 May 2011 23:44:34 +0000
Subject: [PATCH] Fix PR9955 by only attaching load memory operands to load
 instructions and similarly for stores. Now "make check" passes with the
 MachineVerifier forced on with the VerifyCoalescing option!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131705 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp | 40 +++++++++++++++++--
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 2818b326871..f24eb402921 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -2650,11 +2650,45 @@ SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
       // instructions that access memory and for ComplexPatterns that match
       // loads.
       if (EmitNodeInfo & OPFL_MemRefs) {
+        // Only attach load or store memory operands if the generated
+        // instruction may load or store.
+        const TargetInstrDesc &TID = TM.getInstrInfo()->get(TargetOpc);
+        bool mayLoad = TID.mayLoad();
+        bool mayStore = TID.mayStore();
+
+        unsigned NumMemRefs = 0;
+        for (SmallVector<MachineMemOperand*, 2>::const_iterator I =
+             MatchedMemRefs.begin(), E = MatchedMemRefs.end(); I != E; ++I) {
+          if ((*I)->isLoad()) {
+            if (mayLoad)
+              ++NumMemRefs;
+          } else if ((*I)->isStore()) {
+            if (mayStore)
+              ++NumMemRefs;
+          } else {
+            ++NumMemRefs;
+          }
+        }
+
         MachineSDNode::mmo_iterator MemRefs =
-          MF->allocateMemRefsArray(MatchedMemRefs.size());
-        std::copy(MatchedMemRefs.begin(), MatchedMemRefs.end(), MemRefs);
+          MF->allocateMemRefsArray(NumMemRefs);
+
+        MachineSDNode::mmo_iterator MemRefsPos = MemRefs;
+        for (SmallVector<MachineMemOperand*, 2>::const_iterator I =
+             MatchedMemRefs.begin(), E = MatchedMemRefs.end(); I != E; ++I) {
+          if ((*I)->isLoad()) {
+            if (mayLoad)
+              *MemRefsPos++ = *I;
+          } else if ((*I)->isStore()) {
+            if (mayStore)
+              *MemRefsPos++ = *I;
+          } else {
+            *MemRefsPos++ = *I;
+          }
+        }
+
         cast<MachineSDNode>(Res)
-          ->setMemRefs(MemRefs, MemRefs + MatchedMemRefs.size());
+          ->setMemRefs(MemRefs, MemRefs + NumMemRefs);
       }
 
       DEBUG(errs() << "  "