diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 488a9e5fc8a8..ada2242b0c7b 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -33856,6 +33856,9 @@ void X86TargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
     }
     break;
   }
+  case X86ISD::VTRUNC:
+  case X86ISD::VTRUNCS:
+  case X86ISD::VTRUNCUS:
   case X86ISD::CVTSI2P:
   case X86ISD::CVTUI2P:
   case X86ISD::CVTP2SI:
@@ -33872,7 +33875,7 @@ void X86TargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
   case X86ISD::VMFPROUND:
   case X86ISD::CVTPS2PH:
   case X86ISD::MCVTPS2PH: {
-    // Conversions - upper elements are known zero.
+    // Truncations/Conversions - upper elements are known zero.
     EVT SrcVT = Op.getOperand(0).getValueType();
     if (SrcVT.isVector()) {
       unsigned NumSrcElts = SrcVT.getVectorNumElements();
diff --git a/llvm/test/CodeGen/X86/avx512vl-intrinsics-fast-isel.ll b/llvm/test/CodeGen/X86/avx512vl-intrinsics-fast-isel.ll
index 9cda6c97ae0a..83f39c1dd7da 100644
--- a/llvm/test/CodeGen/X86/avx512vl-intrinsics-fast-isel.ll
+++ b/llvm/test/CodeGen/X86/avx512vl-intrinsics-fast-isel.ll
@@ -3418,8 +3418,6 @@ define <2 x i64> @test_mm256_cvtepi64_epi8(<4 x i64> %__A) {
 ; CHECK-LABEL: test_mm256_cvtepi64_epi8:
 ; CHECK:       # %bb.0: # %entry
 ; CHECK-NEXT:    vpmovqb %ymm0, %xmm0
-; CHECK-NEXT:    vpxor %xmm1, %xmm1, %xmm1
-; CHECK-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0,1],xmm1[2,3,4,5,6,7]
 ; CHECK-NEXT:    vzeroupper
 ; CHECK-NEXT:    ret{{[l|q]}}
 entry:
@@ -3433,7 +3431,6 @@ define <2 x i64> @test_mm256_cvtepi64_epi16(<4 x i64> %__A) {
 ; CHECK-LABEL: test_mm256_cvtepi64_epi16:
 ; CHECK:       # %bb.0: # %entry
 ; CHECK-NEXT:    vpmovqw %ymm0, %xmm0
-; CHECK-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; CHECK-NEXT:    vzeroupper
 ; CHECK-NEXT:    ret{{[l|q]}}
 entry:
@@ -3447,7 +3444,6 @@ define <2 x i64> @test_mm256_cvtepi32_epi8(<4 x i64> %__A) {
 ; CHECK-LABEL: test_mm256_cvtepi32_epi8:
 ; CHECK:       # %bb.0: # %entry
 ; CHECK-NEXT:    vpmovdb %ymm0, %xmm0
-; CHECK-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; CHECK-NEXT:    vzeroupper
 ; CHECK-NEXT:    ret{{[l|q]}}
 entry:
diff --git a/llvm/test/CodeGen/X86/shuffle-vs-trunc-256.ll b/llvm/test/CodeGen/X86/shuffle-vs-trunc-256.ll
index 4977e083004b..11c1f2e76f83 100644
--- a/llvm/test/CodeGen/X86/shuffle-vs-trunc-256.ll
+++ b/llvm/test/CodeGen/X86/shuffle-vs-trunc-256.ll
@@ -505,7 +505,6 @@ define <2 x i64> @trunc_v8i32_to_v8i8_return_v2i64(<8 x i32> %vec) nounwind {
 ; AVX512VL-LABEL: trunc_v8i32_to_v8i8_return_v2i64:
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    vpmovdb %ymm0, %xmm0
-; AVX512VL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512VL-NEXT:    vzeroupper
 ; AVX512VL-NEXT:    retq
 ;
@@ -520,14 +519,12 @@ define <2 x i64> @trunc_v8i32_to_v8i8_return_v2i64(<8 x i32> %vec) nounwind {
 ; AVX512BWVL-LABEL: trunc_v8i32_to_v8i8_return_v2i64:
 ; AVX512BWVL:       # %bb.0:
 ; AVX512BWVL-NEXT:    vpmovdb %ymm0, %xmm0
-; AVX512BWVL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512BWVL-NEXT:    vzeroupper
 ; AVX512BWVL-NEXT:    retq
 ;
 ; AVX512VBMIVL-LABEL: trunc_v8i32_to_v8i8_return_v2i64:
 ; AVX512VBMIVL:       # %bb.0:
 ; AVX512VBMIVL-NEXT:    vpmovdb %ymm0, %xmm0
-; AVX512VBMIVL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512VBMIVL-NEXT:    vzeroupper
 ; AVX512VBMIVL-NEXT:    retq
   %truncated.vec = trunc <8 x i32> %vec to <8 x i8>
@@ -685,7 +682,6 @@ define <16 x i8> @trunc_v8i32_to_v8i8_return_v16i8(<8 x i32> %vec) nounwind {
 ; AVX512VL-LABEL: trunc_v8i32_to_v8i8_return_v16i8:
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    vpmovdb %ymm0, %xmm0
-; AVX512VL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512VL-NEXT:    vzeroupper
 ; AVX512VL-NEXT:    retq
 ;
@@ -700,14 +696,12 @@ define <16 x i8> @trunc_v8i32_to_v8i8_return_v16i8(<8 x i32> %vec) nounwind {
 ; AVX512BWVL-LABEL: trunc_v8i32_to_v8i8_return_v16i8:
 ; AVX512BWVL:       # %bb.0:
 ; AVX512BWVL-NEXT:    vpmovdb %ymm0, %xmm0
-; AVX512BWVL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512BWVL-NEXT:    vzeroupper
 ; AVX512BWVL-NEXT:    retq
 ;
 ; AVX512VBMIVL-LABEL: trunc_v8i32_to_v8i8_return_v16i8:
 ; AVX512VBMIVL:       # %bb.0:
 ; AVX512VBMIVL-NEXT:    vpmovdb %ymm0, %xmm0
-; AVX512VBMIVL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512VBMIVL-NEXT:    vzeroupper
 ; AVX512VBMIVL-NEXT:    retq
   %truncated = trunc <8 x i32> %vec to <8 x i8>
@@ -751,7 +745,6 @@ define <2 x i64> @trunc_v4i64_to_v4i16_return_v2i64(<4 x i64> %vec) nounwind {
 ; AVX512VL-LABEL: trunc_v4i64_to_v4i16_return_v2i64:
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    vpmovqw %ymm0, %xmm0
-; AVX512VL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512VL-NEXT:    vzeroupper
 ; AVX512VL-NEXT:    retq
 ;
@@ -766,14 +759,12 @@ define <2 x i64> @trunc_v4i64_to_v4i16_return_v2i64(<4 x i64> %vec) nounwind {
 ; AVX512BWVL-LABEL: trunc_v4i64_to_v4i16_return_v2i64:
 ; AVX512BWVL:       # %bb.0:
 ; AVX512BWVL-NEXT:    vpmovqw %ymm0, %xmm0
-; AVX512BWVL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512BWVL-NEXT:    vzeroupper
 ; AVX512BWVL-NEXT:    retq
 ;
 ; AVX512VBMIVL-LABEL: trunc_v4i64_to_v4i16_return_v2i64:
 ; AVX512VBMIVL:       # %bb.0:
 ; AVX512VBMIVL-NEXT:    vpmovqw %ymm0, %xmm0
-; AVX512VBMIVL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512VBMIVL-NEXT:    vzeroupper
 ; AVX512VBMIVL-NEXT:    retq
   %truncated = trunc <4 x i64> %vec to <4 x i16>
@@ -941,7 +932,6 @@ define <8 x i16> @trunc_v4i64_to_v4i16_return_v8i16(<4 x i64> %vec) nounwind {
 ; AVX512VL-LABEL: trunc_v4i64_to_v4i16_return_v8i16:
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    vpmovqw %ymm0, %xmm0
-; AVX512VL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512VL-NEXT:    vzeroupper
 ; AVX512VL-NEXT:    retq
 ;
@@ -956,14 +946,12 @@ define <8 x i16> @trunc_v4i64_to_v4i16_return_v8i16(<4 x i64> %vec) nounwind {
 ; AVX512BWVL-LABEL: trunc_v4i64_to_v4i16_return_v8i16:
 ; AVX512BWVL:       # %bb.0:
 ; AVX512BWVL-NEXT:    vpmovqw %ymm0, %xmm0
-; AVX512BWVL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512BWVL-NEXT:    vzeroupper
 ; AVX512BWVL-NEXT:    retq
 ;
 ; AVX512VBMIVL-LABEL: trunc_v4i64_to_v4i16_return_v8i16:
 ; AVX512VBMIVL:       # %bb.0:
 ; AVX512VBMIVL-NEXT:    vpmovqw %ymm0, %xmm0
-; AVX512VBMIVL-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512VBMIVL-NEXT:    vzeroupper
 ; AVX512VBMIVL-NEXT:    retq
   %truncated = trunc <4 x i64> %vec to <4 x i16>
@@ -1008,8 +996,6 @@ define <16 x i8> @trunc_v4i64_to_v4i8_return_v16i8(<4 x i64> %vec) nounwind {
 ; AVX512VL-LABEL: trunc_v4i64_to_v4i8_return_v16i8:
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    vpmovqb %ymm0, %xmm0
-; AVX512VL-NEXT:    vpxor %xmm1, %xmm1, %xmm1
-; AVX512VL-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0,1],xmm1[2,3,4,5,6,7]
 ; AVX512VL-NEXT:    vzeroupper
 ; AVX512VL-NEXT:    retq
 ;
@@ -1025,16 +1011,12 @@ define <16 x i8> @trunc_v4i64_to_v4i8_return_v16i8(<4 x i64> %vec) nounwind {
 ; AVX512BWVL-LABEL: trunc_v4i64_to_v4i8_return_v16i8:
 ; AVX512BWVL:       # %bb.0:
 ; AVX512BWVL-NEXT:    vpmovqb %ymm0, %xmm0
-; AVX512BWVL-NEXT:    vpxor %xmm1, %xmm1, %xmm1
-; AVX512BWVL-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0,1],xmm1[2,3,4,5,6,7]
 ; AVX512BWVL-NEXT:    vzeroupper
 ; AVX512BWVL-NEXT:    retq
 ;
 ; AVX512VBMIVL-LABEL: trunc_v4i64_to_v4i8_return_v16i8:
 ; AVX512VBMIVL:       # %bb.0:
 ; AVX512VBMIVL-NEXT:    vpmovqb %ymm0, %xmm0
-; AVX512VBMIVL-NEXT:    vpxor %xmm1, %xmm1, %xmm1
-; AVX512VBMIVL-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0,1],xmm1[2,3,4,5,6,7]
 ; AVX512VBMIVL-NEXT:    vzeroupper
 ; AVX512VBMIVL-NEXT:    retq
   %truncated = trunc <4 x i64> %vec to <4 x i8>
diff --git a/llvm/test/CodeGen/X86/shuffle-vs-trunc-512.ll b/llvm/test/CodeGen/X86/shuffle-vs-trunc-512.ll
index f46607066484..432faf5d12d1 100644
--- a/llvm/test/CodeGen/X86/shuffle-vs-trunc-512.ll
+++ b/llvm/test/CodeGen/X86/shuffle-vs-trunc-512.ll
@@ -499,7 +499,6 @@ define <16 x i8> @trunc_v8i64_to_v8i8_return_v16i8(<8 x i64> %vec) nounwind {
 ; AVX512-LABEL: trunc_v8i64_to_v8i8_return_v16i8:
 ; AVX512:       # %bb.0:
 ; AVX512-NEXT:    vpmovqb %zmm0, %xmm0
-; AVX512-NEXT:    vmovq {{.*#+}} xmm0 = xmm0[0],zero
 ; AVX512-NEXT:    vzeroupper
 ; AVX512-NEXT:    retq
   %truncated = trunc <8 x i64> %vec to <8 x i8>