Index: llvm/trunk/lib/Target/ARM/ARMParallelDSP.cpp
===================================================================
--- llvm/trunk/lib/Target/ARM/ARMParallelDSP.cpp
+++ llvm/trunk/lib/Target/ARM/ARMParallelDSP.cpp
@@ -154,6 +154,8 @@
 
     bool is64Bit() const { return Root->getType()->isIntegerTy(64); }
 
+    Type *getType() const { return Root->getType(); }
+
     /// Return the incoming value to be accumulated. This maybe null.
     Value *getAccumulator() { return Acc; }
 
@@ -652,9 +654,9 @@
     Value *Mul = MulCand->Root;
     LLVM_DEBUG(dbgs() << "Accumulating unpaired mul: " << *Mul << "\n");
 
-    if (R.getRoot()->getType() != Mul->getType()) {
+    if (R.getType() != Mul->getType()) {
       assert(R.is64Bit() && "expected 64-bit result");
-      Mul = Builder.CreateSExt(Mul, R.getRoot()->getType());
+      Mul = Builder.CreateSExt(Mul, R.getType());
     }
 
     if (!Acc) {
@@ -666,10 +668,14 @@
     InsertAfter = cast<Instruction>(Acc);
   }
 
-  if (!Acc)
+  if (!Acc) {
     Acc = R.is64Bit() ?
       ConstantInt::get(IntegerType::get(M->getContext(), 64), 0) :
       ConstantInt::get(IntegerType::get(M->getContext(), 32), 0);
+  } else if (Acc->getType() != R.getType()) {
+    Builder.SetInsertPoint(R.getRoot());
+    Acc = Builder.CreateSExt(Acc, R.getType());
+  }
 
   IntegerType *Ty = IntegerType::get(M->getContext(), 32);
   for (auto &Pair : R.getMulPairs()) {
Index: llvm/trunk/test/CodeGen/ARM/ParallelDSP/blocks.ll
===================================================================
--- llvm/trunk/test/CodeGen/ARM/ParallelDSP/blocks.ll
+++ llvm/trunk/test/CodeGen/ARM/ParallelDSP/blocks.ll
@@ -1,4 +1,4 @@
-; RUN: opt -arm-parallel-dsp -mtriple=armv7-a -S %s -o - | FileCheck %s
+; RUN: opt -arm-parallel-dsp -dce -mtriple=armv7-a -S %s -o - | FileCheck %s
 
 ; CHECK-LABEL: single_block
 ; CHECK: [[CAST_A:%[^ ]+]] = bitcast i16* %a to i32*
Index: llvm/trunk/test/CodeGen/ARM/ParallelDSP/sext-acc.ll
===================================================================
--- llvm/trunk/test/CodeGen/ARM/ParallelDSP/sext-acc.ll
+++ llvm/trunk/test/CodeGen/ARM/ParallelDSP/sext-acc.ll
@@ -0,0 +1,186 @@
+; RUN: opt -arm-parallel-dsp -dce -mtriple=armv7-a -S %s -o - | FileCheck %s
+
+; CHECK-LABEL: sext_acc_1
+; CHECK: [[CAST_A:%[^ ]+]] = bitcast i16* %a to i32*
+; CHECK: [[A:%[^ ]+]] = load i32, i32* [[CAST_A]]
+; CHECK: [[CAST_B:%[^ ]+]] = bitcast i16* %b to i32*
+; CHECK: [[B:%[^ ]+]] = load i32, i32* [[CAST_B]]
+; CHECK: [[ACC:%[^ ]+]] = sext i32 %acc to i64
+; CHECK: call i64 @llvm.arm.smlald(i32 [[A]], i32 [[B]], i64 [[ACC]])
+define i64 @sext_acc_1(i16* %a, i16* %b, i32 %acc) {
+entry:
+  %ld.a.0 = load i16, i16* %a
+  %sext.a.0 = sext i16 %ld.a.0 to i32
+  %ld.b.0 = load i16, i16* %b
+  %sext.b.0 = sext i16 %ld.b.0 to i32
+  %mul.0 = mul i32 %sext.a.0, %sext.b.0
+  %addr.a.1 = getelementptr i16, i16* %a, i32 1
+  %addr.b.1 = getelementptr i16, i16* %b, i32 1
+  %ld.a.1 = load i16, i16* %addr.a.1
+  %sext.a.1 = sext i16 %ld.a.1 to i32
+  %ld.b.1 = load i16, i16* %addr.b.1
+  %sext.b.1 = sext i16 %ld.b.1 to i32
+  %mul.1 = mul i32 %sext.a.1, %sext.b.1
+  %sext.mul.0 = sext i32 %mul.0 to i64
+  %sext.mul.1 = sext i32 %mul.1 to i64
+  %add = add i64 %sext.mul.0, %sext.mul.1
+  %sext.acc = sext i32 %acc to i64
+  %res = add i64 %add, %sext.acc
+  ret i64 %res
+}
+
+; CHECK-LABEL: sext_acc_2
+; CHECK: [[CAST_A:%[^ ]+]] = bitcast i16* %a to i32*
+; CHECK: [[A:%[^ ]+]] = load i32, i32* [[CAST_A]]
+; CHECK: [[CAST_B:%[^ ]+]] = bitcast i16* %b to i32*
+; CHECK: [[B:%[^ ]+]] = load i32, i32* [[CAST_B]]
+; CHECK: [[CAST_A_2:%[^ ]+]] = bitcast i16* %addr.a.2 to i32*
+; CHECK: [[A_2:%[^ ]+]] = load i32, i32* %4
+; CHECK: [[CAST_B_2:%[^ ]+]] = bitcast i16* %addr.b.2 to i32*
+; CHECK: [[B_2:%[^ ]+]] = load i32, i32* %6
+; CHECK: [[ACC:%[^ ]+]] = sext i32 %acc to i64
+; CHECK: [[SMLALD:%[^ ]+]] = call i64 @llvm.arm.smlald(i32 [[A]], i32 [[B]], i64 [[ACC]])
+; CHECK: call i64 @llvm.arm.smlald(i32 [[A_2]], i32 [[B_2]], i64 [[SMLALD]])
+define i64 @sext_acc_2(i16* %a, i16* %b, i32 %acc) {
+entry:
+  %ld.a.0 = load i16, i16* %a
+  %sext.a.0 = sext i16 %ld.a.0 to i32
+  %ld.b.0 = load i16, i16* %b
+  %sext.b.0 = sext i16 %ld.b.0 to i32
+  %mul.0 = mul i32 %sext.a.0, %sext.b.0
+  %addr.a.1 = getelementptr i16, i16* %a, i32 1
+  %addr.b.1 = getelementptr i16, i16* %b, i32 1
+  %ld.a.1 = load i16, i16* %addr.a.1
+  %sext.a.1 = sext i16 %ld.a.1 to i32
+  %ld.b.1 = load i16, i16* %addr.b.1
+  %sext.b.1 = sext i16 %ld.b.1 to i32
+  %mul.1 = mul i32 %sext.a.1, %sext.b.1
+  %sext.mul.0 = sext i32 %mul.0 to i64
+  %sext.mul.1 = sext i32 %mul.1 to i64
+  %add = add i64 %sext.mul.0, %sext.mul.1
+  %sext.acc = sext i32 %acc to i64
+  %add.1 = add i64 %add, %sext.acc
+  %addr.a.2 = getelementptr i16, i16* %a, i32 2
+  %addr.b.2 = getelementptr i16, i16* %b, i32 2
+  %ld.a.2 = load i16, i16* %addr.a.2
+  %sext.a.2 = sext i16 %ld.a.2 to i32
+  %ld.b.2 = load i16, i16* %addr.b.2
+  %sext.b.2 = sext i16 %ld.b.2 to i32
+  %mul.2 = mul i32 %sext.a.2, %sext.b.2
+  %sext.mul.2 = sext i32 %mul.2 to i64
+  %addr.a.3 = getelementptr i16, i16* %a, i32 3
+  %addr.b.3 = getelementptr i16, i16* %b, i32 3
+  %ld.a.3 = load i16, i16* %addr.a.3
+  %sext.a.3 = sext i16 %ld.a.3 to i32
+  %ld.b.3 = load i16, i16* %addr.b.3
+  %sext.b.3 = sext i16 %ld.b.3 to i32
+  %mul.3 = mul i32 %sext.a.3, %sext.b.3
+  %sext.mul.3 = sext i32 %mul.3 to i64
+  %add.2 = add i64 %sext.mul.2, %sext.mul.3
+  %add.3 = add i64 %add.1, %add.2
+  ret i64 %add.3
+}
+
+; CHECK-LABEL: sext_acc_3
+; CHECK: [[CAST_A:%[^ ]+]] = bitcast i16* %a to i32*
+; CHECK: [[A:%[^ ]+]] = load i32, i32* [[CAST_A]]
+; CHECK: [[CAST_B:%[^ ]+]] = bitcast i16* %b to i32*
+; CHECK: [[B:%[^ ]+]] = load i32, i32* [[CAST_B]]
+; CHECK: [[CAST_A_2:%[^ ]+]] = bitcast i16* %addr.a.2 to i32*
+; CHECK: [[A_2:%[^ ]+]] = load i32, i32* %4
+; CHECK: [[CAST_B_2:%[^ ]+]] = bitcast i16* %addr.b.2 to i32*
+; CHECK: [[B_2:%[^ ]+]] = load i32, i32* %6
+; CHECK: [[ACC:%[^ ]+]] = sext i32 %acc to i64
+; CHECK: [[SMLALD:%[^ ]+]] = call i64 @llvm.arm.smlald(i32 [[A]], i32 [[B]], i64 [[ACC]])
+; CHECK: call i64 @llvm.arm.smlald(i32 [[A_2]], i32 [[B_2]], i64 [[SMLALD]])
+define i64 @sext_acc_3(i16* %a, i16* %b, i32 %acc) {
+entry:
+  %ld.a.0 = load i16, i16* %a
+  %sext.a.0 = sext i16 %ld.a.0 to i32
+  %ld.b.0 = load i16, i16* %b
+  %sext.b.0 = sext i16 %ld.b.0 to i32
+  %mul.0 = mul i32 %sext.a.0, %sext.b.0
+  %addr.a.1 = getelementptr i16, i16* %a, i32 1
+  %addr.b.1 = getelementptr i16, i16* %b, i32 1
+  %ld.a.1 = load i16, i16* %addr.a.1
+  %sext.a.1 = sext i16 %ld.a.1 to i32
+  %ld.b.1 = load i16, i16* %addr.b.1
+  %sext.b.1 = sext i16 %ld.b.1 to i32
+  %mul.1 = mul i32 %sext.a.1, %sext.b.1
+  %sext.mul.0 = sext i32 %mul.0 to i64
+  %sext.mul.1 = sext i32 %mul.1 to i64
+  %add = add i64 %sext.mul.0, %sext.mul.1
+  %addr.a.2 = getelementptr i16, i16* %a, i32 2
+  %addr.b.2 = getelementptr i16, i16* %b, i32 2
+  %ld.a.2 = load i16, i16* %addr.a.2
+  %sext.a.2 = sext i16 %ld.a.2 to i32
+  %ld.b.2 = load i16, i16* %addr.b.2
+  %sext.b.2 = sext i16 %ld.b.2 to i32
+  %mul.2 = mul i32 %sext.a.2, %sext.b.2
+  %sext.mul.2 = sext i32 %mul.2 to i64
+  %addr.a.3 = getelementptr i16, i16* %a, i32 3
+  %addr.b.3 = getelementptr i16, i16* %b, i32 3
+  %ld.a.3 = load i16, i16* %addr.a.3
+  %sext.a.3 = sext i16 %ld.a.3 to i32
+  %ld.b.3 = load i16, i16* %addr.b.3
+  %sext.b.3 = sext i16 %ld.b.3 to i32
+  %mul.3 = mul i32 %sext.a.3, %sext.b.3
+  %sext.mul.3 = sext i32 %mul.3 to i64
+  %add.1 = add i64 %sext.mul.2, %sext.mul.3
+  %add.2 = add i64 %add, %add.1
+  %sext.acc = sext i32 %acc to i64
+  %add.3 = add i64 %add.2, %sext.acc
+  ret i64 %add.3
+}
+
+; CHECK-LABEL: sext_acc_4
+; CHECK: [[CAST_A:%[^ ]+]] = bitcast i16* %a to i32*
+; CHECK: [[A:%[^ ]+]] = load i32, i32* [[CAST_A]]
+; CHECK: [[CAST_B:%[^ ]+]] = bitcast i16* %b to i32*
+; CHECK: [[B:%[^ ]+]] = load i32, i32* [[CAST_B]]
+; CHECK: [[CAST_A_2:%[^ ]+]] = bitcast i16* %addr.a.2 to i32*
+; CHECK: [[A_2:%[^ ]+]] = load i32, i32* %4
+; CHECK: [[CAST_B_2:%[^ ]+]] = bitcast i16* %addr.b.2 to i32*
+; CHECK: [[B_2:%[^ ]+]] = load i32, i32* %6
+; CHECK: [[ACC:%[^ ]+]] = sext i32 %acc to i64
+; CHECK: [[SMLALD:%[^ ]+]] = call i64 @llvm.arm.smlald(i32 [[A]], i32 [[B]], i64 [[ACC]])
+; CHECK: call i64 @llvm.arm.smlald(i32 [[A_2]], i32 [[B_2]], i64 [[SMLALD]])
+define i64 @sext_acc_4(i16* %a, i16* %b, i32 %acc) {
+entry:
+  %ld.a.0 = load i16, i16* %a
+  %sext.a.0 = sext i16 %ld.a.0 to i32
+  %ld.b.0 = load i16, i16* %b
+  %sext.b.0 = sext i16 %ld.b.0 to i32
+  %mul.0 = mul i32 %sext.a.0, %sext.b.0
+  %addr.a.1 = getelementptr i16, i16* %a, i32 1
+  %addr.b.1 = getelementptr i16, i16* %b, i32 1
+  %ld.a.1 = load i16, i16* %addr.a.1
+  %sext.a.1 = sext i16 %ld.a.1 to i32
+  %ld.b.1 = load i16, i16* %addr.b.1
+  %sext.b.1 = sext i16 %ld.b.1 to i32
+  %mul.1 = mul i32 %sext.a.1, %sext.b.1
+  %add = add i32 %mul.0, %mul.1
+  %sext.add = sext i32 %add to i64
+  %addr.a.2 = getelementptr i16, i16* %a, i32 2
+  %addr.b.2 = getelementptr i16, i16* %b, i32 2
+  %ld.a.2 = load i16, i16* %addr.a.2
+  %sext.a.2 = sext i16 %ld.a.2 to i32
+  %ld.b.2 = load i16, i16* %addr.b.2
+  %sext.b.2 = sext i16 %ld.b.2 to i32
+  %mul.2 = mul i32 %sext.a.2, %sext.b.2
+  %sext.mul.2 = sext i32 %mul.2 to i64
+  %addr.a.3 = getelementptr i16, i16* %a, i32 3
+  %addr.b.3 = getelementptr i16, i16* %b, i32 3
+  %ld.a.3 = load i16, i16* %addr.a.3
+  %sext.a.3 = sext i16 %ld.a.3 to i32
+  %ld.b.3 = load i16, i16* %addr.b.3
+  %sext.b.3 = sext i16 %ld.b.3 to i32
+  %mul.3 = mul i32 %sext.a.3, %sext.b.3
+  %sext.mul.3 = sext i32 %mul.3 to i64
+  %sext.acc = sext i32 %acc to i64
+  %add.1 = add i64 %sext.mul.2, %sext.add
+  %add.2 = add i64 %sext.add, %add.1
+  %add.3 = add i64 %add.2, %sext.mul.3
+  %add.4 = add i64 %add.3, %sext.acc
+  ret i64 %add.4
+}