diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -5155,6 +5155,7 @@
 
       {6, MVT::v2i64, 6}, // (load 12i64 and) deinterleave into 6 x 2i64
       {6, MVT::v4i64, 18}, // (load 24i64 and) deinterleave into 6 x 4i64
+      {6, MVT::v8i64, 36}, // (load 48i64 and) deinterleave into 6 x 8i64
 
       {8, MVT::v8i32, 40} // (load 64i32 and) deinterleave into 8 x 8i32
   };
@@ -5244,6 +5245,7 @@
 
       {6, MVT::v2i64, 8},  // interleave 6 x 2i64 into 12i64 (and store)
       {6, MVT::v4i64, 15},  // interleave 6 x 4i64 into 24i64 (and store)
+      {6, MVT::v8i64, 30},  // interleave 6 x 8i64 into 48i64 (and store)
   };
 
   if (Opcode == Instruction::Load) {
diff --git a/llvm/test/Analysis/CostModel/X86/interleaved-load-f64-stride-6.ll b/llvm/test/Analysis/CostModel/X86/interleaved-load-f64-stride-6.ll
--- a/llvm/test/Analysis/CostModel/X86/interleaved-load-f64-stride-6.ll
+++ b/llvm/test/Analysis/CostModel/X86/interleaved-load-f64-stride-6.ll
@@ -24,7 +24,7 @@
 ; AVX2: LV: Found an estimated cost of 1 for VF 1 For instruction:   %v0 = load double, double* %in0, align 8
 ; AVX2: LV: Found an estimated cost of 9 for VF 2 For instruction:   %v0 = load double, double* %in0, align 8
 ; AVX2: LV: Found an estimated cost of 24 for VF 4 For instruction:   %v0 = load double, double* %in0, align 8
-; AVX2: LV: Found an estimated cost of 96 for VF 8 For instruction:   %v0 = load double, double* %in0, align 8
+; AVX2: LV: Found an estimated cost of 48 for VF 8 For instruction:   %v0 = load double, double* %in0, align 8
 ;
 ; AVX512: LV: Found an estimated cost of 1 for VF 1 For instruction:   %v0 = load double, double* %in0, align 8
 ; AVX512: LV: Found an estimated cost of 11 for VF 2 For instruction:   %v0 = load double, double* %in0, align 8
diff --git a/llvm/test/Analysis/CostModel/X86/interleaved-load-i64-stride-6.ll b/llvm/test/Analysis/CostModel/X86/interleaved-load-i64-stride-6.ll
--- a/llvm/test/Analysis/CostModel/X86/interleaved-load-i64-stride-6.ll
+++ b/llvm/test/Analysis/CostModel/X86/interleaved-load-i64-stride-6.ll
@@ -24,7 +24,7 @@
 ; AVX2: LV: Found an estimated cost of 1 for VF 1 For instruction:   %v0 = load i64, i64* %in0, align 8
 ; AVX2: LV: Found an estimated cost of 9 for VF 2 For instruction:   %v0 = load i64, i64* %in0, align 8
 ; AVX2: LV: Found an estimated cost of 24 for VF 4 For instruction:   %v0 = load i64, i64* %in0, align 8
-; AVX2: LV: Found an estimated cost of 156 for VF 8 For instruction:   %v0 = load i64, i64* %in0, align 8
+; AVX2: LV: Found an estimated cost of 48 for VF 8 For instruction:   %v0 = load i64, i64* %in0, align 8
 ;
 ; AVX512: LV: Found an estimated cost of 1 for VF 1 For instruction:   %v0 = load i64, i64* %in0, align 8
 ; AVX512: LV: Found an estimated cost of 11 for VF 2 For instruction:   %v0 = load i64, i64* %in0, align 8
diff --git a/llvm/test/Analysis/CostModel/X86/interleaved-store-f64-stride-6.ll b/llvm/test/Analysis/CostModel/X86/interleaved-store-f64-stride-6.ll
--- a/llvm/test/Analysis/CostModel/X86/interleaved-store-f64-stride-6.ll
+++ b/llvm/test/Analysis/CostModel/X86/interleaved-store-f64-stride-6.ll
@@ -24,7 +24,7 @@
 ; AVX2: LV: Found an estimated cost of 1 for VF 1 For instruction:   store double %v5, double* %out5, align 8
 ; AVX2: LV: Found an estimated cost of 11 for VF 2 For instruction:   store double %v5, double* %out5, align 8
 ; AVX2: LV: Found an estimated cost of 21 for VF 4 For instruction:   store double %v5, double* %out5, align 8
-; AVX2: LV: Found an estimated cost of 108 for VF 8 For instruction:   store double %v5, double* %out5, align 8
+; AVX2: LV: Found an estimated cost of 42 for VF 8 For instruction:   store double %v5, double* %out5, align 8
 ;
 ; AVX512: LV: Found an estimated cost of 1 for VF 1 For instruction:   store double %v5, double* %out5, align 8
 ; AVX512: LV: Found an estimated cost of 17 for VF 2 For instruction:   store double %v5, double* %out5, align 8
diff --git a/llvm/test/Analysis/CostModel/X86/interleaved-store-i64-stride-6.ll b/llvm/test/Analysis/CostModel/X86/interleaved-store-i64-stride-6.ll
--- a/llvm/test/Analysis/CostModel/X86/interleaved-store-i64-stride-6.ll
+++ b/llvm/test/Analysis/CostModel/X86/interleaved-store-i64-stride-6.ll
@@ -24,7 +24,7 @@
 ; AVX2: LV: Found an estimated cost of 1 for VF 1 For instruction:   store i64 %v5, i64* %out5, align 8
 ; AVX2: LV: Found an estimated cost of 11 for VF 2 For instruction:   store i64 %v5, i64* %out5, align 8
 ; AVX2: LV: Found an estimated cost of 21 for VF 4 For instruction:   store i64 %v5, i64* %out5, align 8
-; AVX2: LV: Found an estimated cost of 156 for VF 8 For instruction:   store i64 %v5, i64* %out5, align 8
+; AVX2: LV: Found an estimated cost of 42 for VF 8 For instruction:   store i64 %v5, i64* %out5, align 8
 ;
 ; AVX512: LV: Found an estimated cost of 1 for VF 1 For instruction:   store i64 %v5, i64* %out5, align 8
 ; AVX512: LV: Found an estimated cost of 17 for VF 2 For instruction:   store i64 %v5, i64* %out5, align 8