diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
@@ -491,6 +491,7 @@
         {ISD::TRUNCATE, MVT::v4i32, MVT::v4i8, 0},
         {ISD::TRUNCATE, MVT::v8i16, MVT::v8i8, 0},
         {ISD::TRUNCATE, MVT::v8i32, MVT::v8i16, 1},
+        {ISD::TRUNCATE, MVT::v8i32, MVT::v8i8, 1},
         {ISD::TRUNCATE, MVT::v16i32, MVT::v16i8, 3},
         {ISD::TRUNCATE, MVT::v16i16, MVT::v16i8, 1},
     };
@@ -751,6 +752,18 @@
       return Lanes * CallCost;
   }
 
+  if (ISD == ISD::TRUNCATE && ST->hasMVEIntegerOps() &&
+      SrcTy.isFixedLengthVector()) {
+    // Treat a truncate with larger than legal source (128bits for MVE) as
+    // expensive, 2 instructions per lane.
+    if ((SrcTy.getScalarType() == MVT::i8 ||
+         SrcTy.getScalarType() == MVT::i16 ||
+         SrcTy.getScalarType() == MVT::i32) &&
+        SrcTy.getSizeInBits() > 128 &&
+        SrcTy.getSizeInBits() > DstTy.getSizeInBits())
+      return SrcTy.getVectorNumElements() * 2;
+  }
+
   // Scalar integer conversion costs.
   static const TypeConversionCostTblEntry ARMIntegerConversionTbl[] = {
     // i16 -> i64 requires two dependent operations.
diff --git a/llvm/test/Analysis/CostModel/ARM/arith-overflow.ll b/llvm/test/Analysis/CostModel/ARM/arith-overflow.ll
--- a/llvm/test/Analysis/CostModel/ARM/arith-overflow.ll
+++ b/llvm/test/Analysis/CostModel/ARM/arith-overflow.ll
@@ -707,13 +707,13 @@
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 316 for instruction: %V8I32 = call { <8 x i32>, <8 x i1> } @llvm.smul.with.overflow.v8i32(<8 x i32> undef, <8 x i32> undef)
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 1208 for instruction: %V16I32 = call { <16 x i32>, <16 x i1> } @llvm.smul.with.overflow.v16i32(<16 x i32> undef, <16 x i32> undef)
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 6 for instruction: %I16 = call { i16, i1 } @llvm.smul.with.overflow.i16(i16 undef, i16 undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 34 for instruction: %V8I16 = call { <8 x i16>, <8 x i1> } @llvm.smul.with.overflow.v8i16(<8 x i16> undef, <8 x i16> undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 116 for instruction: %V16I16 = call { <16 x i16>, <16 x i1> } @llvm.smul.with.overflow.v16i16(<16 x i16> undef, <16 x i16> undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 424 for instruction: %V32I16 = call { <32 x i16>, <32 x i1> } @llvm.smul.with.overflow.v32i16(<32 x i16> undef, <32 x i16> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 62 for instruction: %V8I16 = call { <8 x i16>, <8 x i1> } @llvm.smul.with.overflow.v8i16(<8 x i16> undef, <8 x i16> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 164 for instruction: %V16I16 = call { <16 x i16>, <16 x i1> } @llvm.smul.with.overflow.v16i16(<16 x i16> undef, <16 x i16> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 488 for instruction: %V32I16 = call { <32 x i16>, <32 x i1> } @llvm.smul.with.overflow.v32i16(<32 x i16> undef, <32 x i16> undef)
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 6 for instruction: %I8 = call { i8, i1 } @llvm.smul.with.overflow.i8(i8 undef, i8 undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 34 for instruction: %V16I8 = call { <16 x i8>, <16 x i1> } @llvm.smul.with.overflow.v16i8(<16 x i8> undef, <16 x i8> undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 116 for instruction: %V32I8 = call { <32 x i8>, <32 x i1> } @llvm.smul.with.overflow.v32i8(<32 x i8> undef, <32 x i8> undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 424 for instruction: %V64I8 = call { <64 x i8>, <64 x i1> } @llvm.smul.with.overflow.v64i8(<64 x i8> undef, <64 x i8> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 94 for instruction: %V16I8 = call { <16 x i8>, <16 x i1> } @llvm.smul.with.overflow.v16i8(<16 x i8> undef, <16 x i8> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 228 for instruction: %V32I8 = call { <32 x i8>, <32 x i1> } @llvm.smul.with.overflow.v32i8(<32 x i8> undef, <32 x i8> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 616 for instruction: %V64I8 = call { <64 x i8>, <64 x i1> } @llvm.smul.with.overflow.v64i8(<64 x i8> undef, <64 x i8> undef)
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret i32 undef
 ;
 ; V8M-SIZE-LABEL: 'smul'
@@ -764,13 +764,13 @@
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 153 for instruction: %V8I32 = call { <8 x i32>, <8 x i1> } @llvm.smul.with.overflow.v8i32(<8 x i32> undef, <8 x i32> undef)
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 557 for instruction: %V16I32 = call { <16 x i32>, <16 x i1> } @llvm.smul.with.overflow.v16i32(<16 x i32> undef, <16 x i32> undef)
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 6 for instruction: %I16 = call { i16, i1 } @llvm.smul.with.overflow.i16(i16 undef, i16 undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 9 for instruction: %V8I16 = call { <8 x i16>, <8 x i1> } @llvm.smul.with.overflow.v8i16(<8 x i16> undef, <8 x i16> undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 13 for instruction: %V16I16 = call { <16 x i16>, <16 x i1> } @llvm.smul.with.overflow.v16i16(<16 x i16> undef, <16 x i16> undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 21 for instruction: %V32I16 = call { <32 x i16>, <32 x i1> } @llvm.smul.with.overflow.v32i16(<32 x i16> undef, <32 x i16> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 39 for instruction: %V8I16 = call { <8 x i16>, <8 x i1> } @llvm.smul.with.overflow.v8i16(<8 x i16> undef, <8 x i16> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 75 for instruction: %V16I16 = call { <16 x i16>, <16 x i1> } @llvm.smul.with.overflow.v16i16(<16 x i16> undef, <16 x i16> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 147 for instruction: %V32I16 = call { <32 x i16>, <32 x i1> } @llvm.smul.with.overflow.v32i16(<32 x i16> undef, <32 x i16> undef)
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 6 for instruction: %I8 = call { i8, i1 } @llvm.smul.with.overflow.i8(i8 undef, i8 undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 9 for instruction: %V16I8 = call { <16 x i8>, <16 x i1> } @llvm.smul.with.overflow.v16i8(<16 x i8> undef, <16 x i8> undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 13 for instruction: %V32I8 = call { <32 x i8>, <32 x i1> } @llvm.smul.with.overflow.v32i8(<32 x i8> undef, <32 x i8> undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 21 for instruction: %V64I8 = call { <64 x i8>, <64 x i1> } @llvm.smul.with.overflow.v64i8(<64 x i8> undef, <64 x i8> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 71 for instruction: %V16I8 = call { <16 x i8>, <16 x i1> } @llvm.smul.with.overflow.v16i8(<16 x i8> undef, <16 x i8> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 139 for instruction: %V32I8 = call { <32 x i8>, <32 x i1> } @llvm.smul.with.overflow.v32i8(<32 x i8> undef, <32 x i8> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 275 for instruction: %V64I8 = call { <64 x i8>, <64 x i1> } @llvm.smul.with.overflow.v64i8(<64 x i8> undef, <64 x i8> undef)
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 undef
 ;
   %I64 = call {i64, i1} @llvm.smul.with.overflow.i64(i64 undef, i64 undef)
@@ -865,13 +865,13 @@
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 312 for instruction: %V8I32 = call { <8 x i32>, <8 x i1> } @llvm.umul.with.overflow.v8i32(<8 x i32> undef, <8 x i32> undef)
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 1200 for instruction: %V16I32 = call { <16 x i32>, <16 x i1> } @llvm.umul.with.overflow.v16i32(<16 x i32> undef, <16 x i32> undef)
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %I16 = call { i16, i1 } @llvm.umul.with.overflow.i16(i16 undef, i16 undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %V8I16 = call { <8 x i16>, <8 x i1> } @llvm.umul.with.overflow.v8i16(<8 x i16> undef, <8 x i16> undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 112 for instruction: %V16I16 = call { <16 x i16>, <16 x i1> } @llvm.umul.with.overflow.v16i16(<16 x i16> undef, <16 x i16> undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 416 for instruction: %V32I16 = call { <32 x i16>, <32 x i1> } @llvm.umul.with.overflow.v32i16(<32 x i16> undef, <32 x i16> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 60 for instruction: %V8I16 = call { <8 x i16>, <8 x i1> } @llvm.umul.with.overflow.v8i16(<8 x i16> undef, <8 x i16> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 160 for instruction: %V16I16 = call { <16 x i16>, <16 x i1> } @llvm.umul.with.overflow.v16i16(<16 x i16> undef, <16 x i16> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 480 for instruction: %V32I16 = call { <32 x i16>, <32 x i1> } @llvm.umul.with.overflow.v32i16(<32 x i16> undef, <32 x i16> undef)
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %I8 = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 undef, i8 undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %V16I8 = call { <16 x i8>, <16 x i1> } @llvm.umul.with.overflow.v16i8(<16 x i8> undef, <16 x i8> undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 112 for instruction: %V32I8 = call { <32 x i8>, <32 x i1> } @llvm.umul.with.overflow.v32i8(<32 x i8> undef, <32 x i8> undef)
-; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 416 for instruction: %V64I8 = call { <64 x i8>, <64 x i1> } @llvm.umul.with.overflow.v64i8(<64 x i8> undef, <64 x i8> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 92 for instruction: %V16I8 = call { <16 x i8>, <16 x i1> } @llvm.umul.with.overflow.v16i8(<16 x i8> undef, <16 x i8> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 224 for instruction: %V32I8 = call { <32 x i8>, <32 x i1> } @llvm.umul.with.overflow.v32i8(<32 x i8> undef, <32 x i8> undef)
+; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 608 for instruction: %V64I8 = call { <64 x i8>, <64 x i1> } @llvm.umul.with.overflow.v64i8(<64 x i8> undef, <64 x i8> undef)
 ; MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret i32 undef
 ;
 ; V8M-SIZE-LABEL: 'umul'
@@ -922,13 +922,13 @@
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 151 for instruction: %V8I32 = call { <8 x i32>, <8 x i1> } @llvm.umul.with.overflow.v8i32(<8 x i32> undef, <8 x i32> undef)
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 553 for instruction: %V16I32 = call { <16 x i32>, <16 x i1> } @llvm.umul.with.overflow.v16i32(<16 x i32> undef, <16 x i32> undef)
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %I16 = call { i16, i1 } @llvm.umul.with.overflow.i16(i16 undef, i16 undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 8 for instruction: %V8I16 = call { <8 x i16>, <8 x i1> } @llvm.umul.with.overflow.v8i16(<8 x i16> undef, <8 x i16> undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 11 for instruction: %V16I16 = call { <16 x i16>, <16 x i1> } @llvm.umul.with.overflow.v16i16(<16 x i16> undef, <16 x i16> undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 17 for instruction: %V32I16 = call { <32 x i16>, <32 x i1> } @llvm.umul.with.overflow.v32i16(<32 x i16> undef, <32 x i16> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 38 for instruction: %V8I16 = call { <8 x i16>, <8 x i1> } @llvm.umul.with.overflow.v8i16(<8 x i16> undef, <8 x i16> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 73 for instruction: %V16I16 = call { <16 x i16>, <16 x i1> } @llvm.umul.with.overflow.v16i16(<16 x i16> undef, <16 x i16> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 143 for instruction: %V32I16 = call { <32 x i16>, <32 x i1> } @llvm.umul.with.overflow.v32i16(<32 x i16> undef, <32 x i16> undef)
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %I8 = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 undef, i8 undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 8 for instruction: %V16I8 = call { <16 x i8>, <16 x i1> } @llvm.umul.with.overflow.v16i8(<16 x i8> undef, <16 x i8> undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 11 for instruction: %V32I8 = call { <32 x i8>, <32 x i1> } @llvm.umul.with.overflow.v32i8(<32 x i8> undef, <32 x i8> undef)
-; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 17 for instruction: %V64I8 = call { <64 x i8>, <64 x i1> } @llvm.umul.with.overflow.v64i8(<64 x i8> undef, <64 x i8> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 70 for instruction: %V16I8 = call { <16 x i8>, <16 x i1> } @llvm.umul.with.overflow.v16i8(<16 x i8> undef, <16 x i8> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 137 for instruction: %V32I8 = call { <32 x i8>, <32 x i1> } @llvm.umul.with.overflow.v32i8(<32 x i8> undef, <32 x i8> undef)
+; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 271 for instruction: %V64I8 = call { <64 x i8>, <64 x i1> } @llvm.umul.with.overflow.v64i8(<64 x i8> undef, <64 x i8> undef)
 ; MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 undef
 ;
   %I64 = call {i64, i1} @llvm.umul.with.overflow.i64(i64 undef, i64 undef)
diff --git a/llvm/test/Analysis/CostModel/ARM/cast.ll b/llvm/test/Analysis/CostModel/ARM/cast.ll
--- a/llvm/test/Analysis/CostModel/ARM/cast.ll
+++ b/llvm/test/Analysis/CostModel/ARM/cast.ll
@@ -521,12 +521,12 @@
 ; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %tv4i32i8 = trunc <4 x i32> undef to <4 x i8>
 ; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %tv4i32i16 = trunc <4 x i32> undef to <4 x i16>
 ; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %tv4i16i8 = trunc <4 x i16> undef to <4 x i8>
-; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %tv8i32i8 = trunc <8 x i32> undef to <8 x i8>
-; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %tv8i32i16 = trunc <8 x i32> undef to <8 x i16>
+; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %tv8i32i8 = trunc <8 x i32> undef to <8 x i8>
+; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %tv8i32i16 = trunc <8 x i32> undef to <8 x i16>
 ; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %tv8i16i8 = trunc <8 x i16> undef to <8 x i8>
-; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 10 for instruction: %tv16i32i8 = trunc <16 x i32> undef to <16 x i8>
-; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 8 for instruction: %tv16i32i16 = trunc <16 x i32> undef to <16 x i16>
-; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %tv16i16i8 = trunc <16 x i16> undef to <16 x i8>
+; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %tv16i32i8 = trunc <16 x i32> undef to <16 x i8>
+; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %tv16i32i16 = trunc <16 x i32> undef to <16 x i16>
+; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %tv16i16i8 = trunc <16 x i16> undef to <16 x i8>
 ; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 10 for instruction: %r80df = fptrunc double undef to float
 ; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 20 for instruction: %r81df = fptrunc <2 x double> undef to <2 x float>
 ; CHECK-MVE-RECIP-NEXT:  Cost Model: Found an estimated cost of 40 for instruction: %r82df = fptrunc <4 x double> undef to <4 x float>
@@ -2097,12 +2097,12 @@
 ; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %tv4i32i8 = trunc <4 x i32> undef to <4 x i8>
 ; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %tv4i32i16 = trunc <4 x i32> undef to <4 x i16>
 ; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %tv4i16i8 = trunc <4 x i16> undef to <4 x i8>
-; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %tv8i32i8 = trunc <8 x i32> undef to <8 x i8>
-; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %tv8i32i16 = trunc <8 x i32> undef to <8 x i16>
+; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %tv8i32i8 = trunc <8 x i32> undef to <8 x i8>
+; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %tv8i32i16 = trunc <8 x i32> undef to <8 x i16>
 ; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %tv8i16i8 = trunc <8 x i16> undef to <8 x i8>
-; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %tv16i32i8 = trunc <16 x i32> undef to <16 x i8>
-; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %tv16i32i16 = trunc <16 x i32> undef to <16 x i16>
-; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %tv16i16i8 = trunc <16 x i16> undef to <16 x i8>
+; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %tv16i32i8 = trunc <16 x i32> undef to <16 x i8>
+; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %tv16i32i16 = trunc <16 x i32> undef to <16 x i16>
+; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %tv16i16i8 = trunc <16 x i16> undef to <16 x i8>
 ; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 10 for instruction: %r80df = fptrunc double undef to float
 ; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 20 for instruction: %r81df = fptrunc <2 x double> undef to <2 x float>
 ; CHECK-MVE-SIZE-NEXT:  Cost Model: Found an estimated cost of 40 for instruction: %r82df = fptrunc <4 x double> undef to <4 x float>
diff --git a/llvm/test/Analysis/CostModel/ARM/mve-gather-scatter-cost.ll b/llvm/test/Analysis/CostModel/ARM/mve-gather-scatter-cost.ll
--- a/llvm/test/Analysis/CostModel/ARM/mve-gather-scatter-cost.ll
+++ b/llvm/test/Analysis/CostModel/ARM/mve-gather-scatter-cost.ll
@@ -358,11 +358,11 @@
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 136 for instruction: call void @llvm.masked.scatter.v8i16.v8p0i16(<8 x i16> %resbs, <8 x i16*> %gepbsb, i32 2, <8 x i1> %mask)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 10 for instruction: %indzext4 = zext <8 x i16> %ind16 to <8 x i32>
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %gep4 = getelementptr i16, i16* %base, <8 x i32> %indzext4
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %indtrunc = trunc <8 x i32> %ind32 to <8 x i16>
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %indtrunc = trunc <8 x i32> %ind32 to <8 x i16>
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: call void @llvm.masked.scatter.v8i16.v8p0i16(<8 x i16> %indtrunc, <8 x i16*> %gep4, i32 2, <8 x i1> %mask)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %res = call <8 x i16> @llvm.masked.gather.v8i16.v8p0i16(<8 x i16*> %gep4, i32 2, <8 x i1> %mask, <8 x i16> undef)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 10 for instruction: %ressext = sext <8 x i16> %res to <8 x i32>
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %restrunc = trunc <8 x i32> %ressext to <8 x i16>
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %restrunc = trunc <8 x i32> %ressext to <8 x i16>
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: call void @llvm.masked.scatter.v8i16.v8p0i16(<8 x i16> %restrunc, <8 x i16*> %gep4, i32 4, <8 x i1> %mask)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
 ;
@@ -525,7 +525,7 @@
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 528 for instruction: call void @llvm.masked.scatter.v16i8.v16p0i8(<16 x i8> %resbs, <16 x i8*> %gepbsb, i32 2, <16 x i1> %mask)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 74 for instruction: %indzext4 = zext <16 x i8> %ind8 to <16 x i32>
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %gep4 = getelementptr i8, i8* %base, <16 x i32> %indzext
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 10 for instruction: %indtrunc = trunc <16 x i32> %ind32 to <16 x i8>
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %indtrunc = trunc <16 x i32> %ind32 to <16 x i8>
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: call void @llvm.masked.scatter.v16i8.v16p0i8(<16 x i8> %indtrunc, <16 x i8*> %gep4, i32 2, <16 x i1> %mask)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
 ;