diff --git a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
index cc360483053c19..feb4e8f571186b 100644
--- a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
@@ -300,6 +300,20 @@ InstructionCost RISCVTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst,
     case ISD::FP_TO_UINT:
     case ISD::SINT_TO_FP:
     case ISD::UINT_TO_FP:
+      if (Src->getScalarSizeInBits() == 1 || Dst->getScalarSizeInBits() == 1) {
+        // The cost of convert from or to mask vector is different from other
+        // cases. We could not use PowDiff to calculate it.
+        // For mask vector to fp, we should use the following instructions:
+        // vmv.v.i v8, 0
+        // vmerge.vim v8, v8, -1, v0
+        // vfcvt.f.x.v v8, v8
+
+        // And for fp vector to mask, we use:
+        // vfncvt.rtz.x.f.w v9, v8
+        // vand.vi v8, v9, 1
+        // vmsne.vi v0, v8, 0
+        return 3;
+      }
       if (std::abs(PowDiff) <= 1)
         return 1;
       // Backend could lower (v[sz]ext i8 to double) to vfcvt(v[sz]ext.f8 i8),
diff --git a/llvm/test/Analysis/CostModel/RISCV/cast.ll b/llvm/test/Analysis/CostModel/RISCV/cast.ll
index 981c2cb98aeb6d..4109eac11ac560 100644
--- a/llvm/test/Analysis/CostModel/RISCV/cast.ll
+++ b/llvm/test/Analysis/CostModel/RISCV/cast.ll
@@ -159,6 +159,7 @@ define void @fp_to_int() {
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %s9 = fptosi <4 x half> undef to <4 x i64>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %s10 = fptosi <4 x float> undef to <4 x i64>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %s11 = fptosi <4 x double> undef to <4 x i16>
+; RISCV32-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %s12 = fptosi <4 x double> undef to <4 x i1>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %u0 = fptoui <4 x half> undef to <4 x i8>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u1 = fptoui <4 x float> undef to <4 x i8>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %u2 = fptoui <4 x double> undef to <4 x i8>
@@ -171,6 +172,7 @@ define void @fp_to_int() {
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u9 = fptoui <4 x half> undef to <4 x i64>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %u10 = fptoui <4 x float> undef to <4 x i64>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u11 = fptoui <4 x double> undef to <4 x i16>
+; RISCV32-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %u12 = fptoui <4 x double> undef to <4 x i1>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
 ;
 ; RISCV64-LABEL: 'fp_to_int'
@@ -186,6 +188,7 @@ define void @fp_to_int() {
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %s9 = fptosi <4 x half> undef to <4 x i64>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %s10 = fptosi <4 x float> undef to <4 x i64>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %s11 = fptosi <4 x double> undef to <4 x i16>
+; RISCV64-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %s12 = fptosi <4 x double> undef to <4 x i1>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %u0 = fptoui <4 x half> undef to <4 x i8>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u1 = fptoui <4 x float> undef to <4 x i8>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %u2 = fptoui <4 x double> undef to <4 x i8>
@@ -198,6 +201,7 @@ define void @fp_to_int() {
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u9 = fptoui <4 x half> undef to <4 x i64>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %u10 = fptoui <4 x float> undef to <4 x i64>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u11 = fptoui <4 x double> undef to <4 x i16>
+; RISCV64-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %u12 = fptoui <4 x double> undef to <4 x i1>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
 ;
   %s0 = fptosi <4 x half> undef to <4 x i8>
@@ -212,6 +216,7 @@ define void @fp_to_int() {
   %s9 = fptosi <4 x half> undef to <4 x i64>
   %s10 = fptosi <4 x float> undef to <4 x i64>
   %s11 = fptosi <4 x double> undef to <4 x i16>
+  %s12 = fptosi <4 x double> undef to <4 x i1>
 
   %u0 = fptoui <4 x half> undef to <4 x i8>
   %u1 = fptoui <4 x float> undef to <4 x i8>
@@ -225,6 +230,8 @@ define void @fp_to_int() {
   %u9 = fptoui <4 x half> undef to <4 x i64>
   %u10 = fptoui <4 x float> undef to <4 x i64>
   %u11 = fptoui <4 x double> undef to <4 x i16>
+  %u12 = fptoui <4 x double> undef to <4 x i1>
+
   ret void
 }
 
@@ -242,6 +249,7 @@ define void @int_to_fp() {
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %s9 = sitofp <4 x i64> undef to <4 x half>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %s10 = sitofp <4 x i64> undef to <4 x float>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %s11 = sitofp <4 x i16> undef to <4 x double>
+; RISCV32-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %s12 = sitofp <4 x i1> undef to <4 x double>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %u0 = uitofp <4 x i8> undef to <4 x half>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u1 = uitofp <4 x i8> undef to <4 x float>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u2 = uitofp <4 x i8> undef to <4 x double>
@@ -254,6 +262,7 @@ define void @int_to_fp() {
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u9 = uitofp <4 x i64> undef to <4 x half>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %u10 = uitofp <4 x i64> undef to <4 x float>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u11 = uitofp <4 x i16> undef to <4 x double>
+; RISCV32-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %u12 = uitofp <4 x i1> undef to <4 x double>
 ; RISCV32-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
 ;
 ; RISCV64-LABEL: 'int_to_fp'
@@ -269,6 +278,7 @@ define void @int_to_fp() {
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %s9 = sitofp <4 x i64> undef to <4 x half>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %s10 = sitofp <4 x i64> undef to <4 x float>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %s11 = sitofp <4 x i16> undef to <4 x double>
+; RISCV64-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %s12 = sitofp <4 x i1> undef to <4 x double>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %u0 = uitofp <4 x i8> undef to <4 x half>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u1 = uitofp <4 x i8> undef to <4 x float>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u2 = uitofp <4 x i8> undef to <4 x double>
@@ -281,6 +291,7 @@ define void @int_to_fp() {
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u9 = uitofp <4 x i64> undef to <4 x half>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %u10 = uitofp <4 x i64> undef to <4 x float>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %u11 = uitofp <4 x i16> undef to <4 x double>
+; RISCV64-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %u12 = uitofp <4 x i1> undef to <4 x double>
 ; RISCV64-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
 ;
   %s0 = sitofp <4 x i8> undef to <4 x half>
@@ -295,6 +306,7 @@ define void @int_to_fp() {
   %s9 = sitofp <4 x i64> undef to <4 x half>
   %s10 = sitofp <4 x i64> undef to <4 x float>
   %s11 = sitofp <4 x i16> undef to <4 x double>
+  %s12 = sitofp <4 x i1> undef to <4 x double>
 
   %u0 = uitofp <4 x i8> undef to <4 x half>
   %u1 = uitofp <4 x i8> undef to <4 x float>
@@ -308,5 +320,7 @@ define void @int_to_fp() {
   %u9 = uitofp <4 x i64> undef to <4 x half>
   %u10 = uitofp <4 x i64> undef to <4 x float>
   %u11 = uitofp <4 x i16> undef to <4 x double>
+  %u12 = uitofp <4 x i1> undef to <4 x double>
+
   ret void
 }