From 95bc85e4eefdfc1aabfde85daf752f05d2a60701 Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Fri, 11 Nov 2011 22:18:09 +0000
Subject: Preserve MachineMemOperands in ARMLoadStoreOptimizer.

Fixes PR8113.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144409 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMLoadStoreOptimizer.cpp | 22 ++++++++++++++++++++++
 test/CodeGen/ARM/ldrd-memoper.ll         | 15 +++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 test/CodeGen/ARM/ldrd-memoper.ll

diff --git a/lib/Target/ARM/ARMLoadStoreOptimizer.cpp b/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
index 4c3be89b3ec..c8728f4ade4 100644
--- a/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
+++ b/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
@@ -32,6 +32,7 @@
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallPtrSet.h"
@@ -1504,6 +1505,23 @@ static bool IsSafeAndProfitableToMove(bool isLd, unsigned Base,
   return AddedRegPressure.size() <= MemRegs.size() * 2;
 }
 
+
+/// Copy Op0 and Op1 operands into a new array assigned to MI.
+static void concatenateMemOperands(MachineInstr *MI, MachineInstr *Op0,
+                                   MachineInstr *Op1) {
+  assert(MI->memoperands_empty() && "expected a new machineinstr");
+  size_t numMemRefs = (Op0->memoperands_end() - Op0->memoperands_begin())
+    + (Op1->memoperands_end() - Op1->memoperands_begin());
+
+  MachineFunction *MF = MI->getParent()->getParent();
+  MachineSDNode::mmo_iterator MemBegin = MF->allocateMemRefsArray(numMemRefs);
+  MachineSDNode::mmo_iterator MemEnd =
+    std::copy(Op0->memoperands_begin(), Op0->memoperands_end(), MemBegin);
+  MemEnd =
+    std::copy(Op1->memoperands_begin(), Op1->memoperands_end(), MemEnd);
+  MI->setMemRefs(MemBegin, MemEnd);
+}
+
 bool
 ARMPreAllocLoadStoreOpt::CanFormLdStDWord(MachineInstr *Op0, MachineInstr *Op1,
                                           DebugLoc &dl,
@@ -1698,6 +1716,8 @@ bool ARMPreAllocLoadStoreOpt::RescheduleOps(MachineBasicBlock *MBB,
             if (!isT2)
               MIB.addReg(0);
             MIB.addImm(Offset).addImm(Pred).addReg(PredReg);
+            concatenateMemOperands(MIB, Op0, Op1);
+            DEBUG(dbgs() << "Formed " << *MIB << "\n");
             ++NumLDRDFormed;
           } else {
             MachineInstrBuilder MIB = BuildMI(*MBB, InsertPos, dl, MCID)
@@ -1710,6 +1730,8 @@ bool ARMPreAllocLoadStoreOpt::RescheduleOps(MachineBasicBlock *MBB,
             if (!isT2)
               MIB.addReg(0);
             MIB.addImm(Offset).addImm(Pred).addReg(PredReg);
+            concatenateMemOperands(MIB, Op0, Op1);
+            DEBUG(dbgs() << "Formed " << *MIB << "\n");
             ++NumSTRDFormed;
           }
           MBB->erase(Op0);
diff --git a/test/CodeGen/ARM/ldrd-memoper.ll b/test/CodeGen/ARM/ldrd-memoper.ll
new file mode 100644
index 00000000000..f1a1121f6aa
--- /dev/null
+++ b/test/CodeGen/ARM/ldrd-memoper.ll
@@ -0,0 +1,15 @@
+; RUN: llc %s -o /dev/null -mtriple=thumbv7-apple-ios -mcpu=cortex-a8 -debug-only=arm-ldst-opt 2> %t
+; RUN: FileCheck %s < %t
+; REQUIRES: asserts
+; PR8113: ARMLoadStoreOptimizer must preserve memoperands.
+
+@b = external global i64*
+
+; CHECK: Formed {{.*}} t2LDRD{{.*}} mem:LD4[%0] LD4[%0+4]
+define i64 @t(i64 %a) nounwind readonly {
+entry:
+	%0 = load i64** @b, align 4
+	%1 = load i64* %0, align 4
+	%2 = mul i64 %1, %a
+	ret i64 %2
+}
-- 
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