Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
===================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1996,6 +1996,21 @@
       return replaceInstUsesWith(*II, V);
     break;
 
+  case Intrinsic::x86_sse2_pmulu_dq:
+  case Intrinsic::x86_sse41_pmuldq:
+  case Intrinsic::x86_avx2_pmul_dq:
+  case Intrinsic::x86_avx2_pmulu_dq: {
+    unsigned VWidth = II->getType()->getVectorNumElements();
+    APInt UndefElts(VWidth, 0);
+    APInt DemandedElts = APInt::getAllOnesValue(VWidth);
+    if (Value *V = SimplifyDemandedVectorElts(II, DemandedElts, UndefElts)) {
+      if (V != II)
+        return replaceInstUsesWith(*II, V);
+      return II;
+    }
+    break;
+  }
+
   case Intrinsic::x86_sse41_insertps:
     if (Value *V = simplifyX86insertps(*II, *Builder))
       return replaceInstUsesWith(*II, V);
Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
===================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -1431,6 +1431,33 @@
 
       break;
 
+    case Intrinsic::x86_sse2_pmulu_dq:
+    case Intrinsic::x86_sse41_pmuldq:
+    case Intrinsic::x86_avx2_pmul_dq:
+    case Intrinsic::x86_avx2_pmulu_dq: {
+      Value *Op0 = II->getArgOperand(0);
+      Value *Op1 = II->getArgOperand(1);
+      unsigned InnerVWidth = Op0->getType()->getVectorNumElements();
+      assert((VWidth * 2) == InnerVWidth && "Unexpected input size");
+
+      APInt InnerDemandedElts(InnerVWidth, 0);
+      for (unsigned i = 0; i != VWidth; ++i)
+        if (DemandedElts[i])
+          InnerDemandedElts.setBit(i * 2);
+
+      UndefElts2 = APInt(InnerVWidth, 0);
+      TmpV = SimplifyDemandedVectorElts(Op0, InnerDemandedElts, UndefElts2,
+                                        Depth + 1);
+      if (TmpV) { II->setArgOperand(0, TmpV); MadeChange = true; }
+
+      UndefElts3 = APInt(InnerVWidth, 0);
+      TmpV = SimplifyDemandedVectorElts(Op1, InnerDemandedElts, UndefElts3,
+                                        Depth + 1);
+      if (TmpV) { II->setArgOperand(1, TmpV); MadeChange = true; }
+
+      break;
+    }
+
     // SSE4A instructions leave the upper 64-bits of the 128-bit result
     // in an undefined state.
     case Intrinsic::x86_sse4a_extrq:
Index: llvm/trunk/test/Transforms/InstCombine/x86-muldq.ll
===================================================================
--- llvm/trunk/test/Transforms/InstCombine/x86-muldq.ll
+++ llvm/trunk/test/Transforms/InstCombine/x86-muldq.ll
@@ -7,11 +7,10 @@
 
 define <2 x i64> @test_demanded_elts_pmuludq_128(<4 x i32> %a0, <4 x i32> %a1) {
 ; CHECK-LABEL: @test_demanded_elts_pmuludq_128(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <4 x i32> %a0, <4 x i32> undef, <4 x i32> <i32 0, i32 0, i32 2, i32 2>
-; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <4 x i32> %a1, <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 3, i32 3>
-; CHECK-NEXT:    [[TMP3:%.*]] = call <2 x i64> @llvm.x86.sse2.pmulu.dq(<4 x i32> [[TMP1]], <4 x i32> [[TMP2]])
-; CHECK-NEXT:    [[TMP4:%.*]] = shufflevector <2 x i64> [[TMP3]], <2 x i64> undef, <2 x i32> zeroinitializer
-; CHECK-NEXT:    ret <2 x i64> [[TMP4]]
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <4 x i32> %a1, <4 x i32> undef, <4 x i32> <i32 1, i32 undef, i32 undef, i32 undef>
+; CHECK-NEXT:    [[TMP2:%.*]] = call <2 x i64> @llvm.x86.sse2.pmulu.dq(<4 x i32> %a0, <4 x i32> [[TMP1]])
+; CHECK-NEXT:    [[TMP3:%.*]] = shufflevector <2 x i64> [[TMP2]], <2 x i64> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    ret <2 x i64> [[TMP3]]
 ;
   %1 = shufflevector <4 x i32> %a0, <4 x i32> undef, <4 x i32> <i32 0, i32 0, i32 2, i32 2>
   %2 = shufflevector <4 x i32> %a1, <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 3, i32 3>
@@ -22,10 +21,9 @@
 
 define <4 x i64> @test_demanded_elts_pmuludq_256(<8 x i32> %a0, <8 x i32> %a1) {
 ; CHECK-LABEL: @test_demanded_elts_pmuludq_256(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> %a0, <8 x i32> undef, <8 x i32> <i32 0, i32 0, i32 2, i32 2, i32 4, i32 4, i32 6, i32 6>
-; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <8 x i32> %a1, <8 x i32> undef, <8 x i32> <i32 1, i32 1, i32 3, i32 3, i32 5, i32 5, i32 7, i32 7>
-; CHECK-NEXT:    [[TMP3:%.*]] = call <4 x i64> @llvm.x86.avx2.pmulu.dq(<8 x i32> [[TMP1]], <8 x i32> [[TMP2]])
-; CHECK-NEXT:    ret <4 x i64> [[TMP3]]
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> %a1, <8 x i32> undef, <8 x i32> <i32 1, i32 undef, i32 3, i32 undef, i32 5, i32 undef, i32 7, i32 undef>
+; CHECK-NEXT:    [[TMP2:%.*]] = call <4 x i64> @llvm.x86.avx2.pmulu.dq(<8 x i32> %a0, <8 x i32> [[TMP1]])
+; CHECK-NEXT:    ret <4 x i64> [[TMP2]]
 ;
   %1 = shufflevector <8 x i32> %a0, <8 x i32> undef, <8 x i32> <i32 0, i32 0, i32 2, i32 2, i32 4, i32 4, i32 6, i32 6>
   %2 = shufflevector <8 x i32> %a1, <8 x i32> undef, <8 x i32> <i32 1, i32 1, i32 3, i32 3, i32 5, i32 5, i32 7, i32 7>
@@ -35,10 +33,9 @@
 
 define <2 x i64> @test_demanded_elts_pmuldq_128(<4 x i32> %a0, <4 x i32> %a1) {
 ; CHECK-LABEL: @test_demanded_elts_pmuldq_128(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <4 x i32> %a0, <4 x i32> undef, <4 x i32> <i32 0, i32 0, i32 2, i32 2>
-; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <4 x i32> %a1, <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 3, i32 3>
-; CHECK-NEXT:    [[TMP3:%.*]] = call <2 x i64> @llvm.x86.sse41.pmuldq(<4 x i32> [[TMP1]], <4 x i32> [[TMP2]])
-; CHECK-NEXT:    ret <2 x i64> [[TMP3]]
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <4 x i32> %a1, <4 x i32> undef, <4 x i32> <i32 1, i32 undef, i32 3, i32 undef>
+; CHECK-NEXT:    [[TMP2:%.*]] = call <2 x i64> @llvm.x86.sse41.pmuldq(<4 x i32> %a0, <4 x i32> [[TMP1]])
+; CHECK-NEXT:    ret <2 x i64> [[TMP2]]
 ;
   %1 = shufflevector <4 x i32> %a0, <4 x i32> undef, <4 x i32> <i32 0, i32 0, i32 2, i32 2>
   %2 = shufflevector <4 x i32> %a1, <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 3, i32 3>
@@ -48,11 +45,10 @@
 
 define <4 x i64> @test_demanded_elts_pmuluq_256(<8 x i32> %a0, <8 x i32> %a1) {
 ; CHECK-LABEL: @test_demanded_elts_pmuluq_256(
-; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> %a0, <8 x i32> undef, <8 x i32> <i32 0, i32 0, i32 2, i32 2, i32 4, i32 4, i32 6, i32 6>
-; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <8 x i32> %a1, <8 x i32> undef, <8 x i32> <i32 1, i32 1, i32 3, i32 3, i32 5, i32 5, i32 7, i32 7>
-; CHECK-NEXT:    [[TMP3:%.*]] = call <4 x i64> @llvm.x86.avx2.pmul.dq(<8 x i32> [[TMP1]], <8 x i32> [[TMP2]])
-; CHECK-NEXT:    [[TMP4:%.*]] = shufflevector <4 x i64> [[TMP3]], <4 x i64> undef, <4 x i32> <i32 0, i32 0, i32 3, i32 3>
-; CHECK-NEXT:    ret <4 x i64> [[TMP4]]
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> %a1, <8 x i32> undef, <8 x i32> <i32 1, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 7, i32 undef>
+; CHECK-NEXT:    [[TMP2:%.*]] = call <4 x i64> @llvm.x86.avx2.pmul.dq(<8 x i32> %a0, <8 x i32> [[TMP1]])
+; CHECK-NEXT:    [[TMP3:%.*]] = shufflevector <4 x i64> [[TMP2]], <4 x i64> undef, <4 x i32> <i32 0, i32 0, i32 3, i32 3>
+; CHECK-NEXT:    ret <4 x i64> [[TMP3]]
 ;
   %1 = shufflevector <8 x i32> %a0, <8 x i32> undef, <8 x i32> <i32 0, i32 0, i32 2, i32 2, i32 4, i32 4, i32 6, i32 6>
   %2 = shufflevector <8 x i32> %a1, <8 x i32> undef, <8 x i32> <i32 1, i32 1, i32 3, i32 3, i32 5, i32 5, i32 7, i32 7>