diff --git a/src/cmd/asm/internal/asm/testdata/arm64.s b/src/cmd/asm/internal/asm/testdata/arm64.s
index d859171103..1146c1a789 100644
--- a/src/cmd/asm/internal/asm/testdata/arm64.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64.s
@@ -596,9 +596,12 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	VMOV	R20, V1.S[0]          // 811e044e
 	VMOV	R20, V1.S[1]          // 811e0c4e
 	VMOV	R1, V9.H4             // 290c020e
+	VDUP	R1, V9.H4             // 290c020e
 	VMOV	R22, V11.D2           // cb0e084e
+	VDUP	R22, V11.D2           // cb0e084e
 	VMOV	V2.B16, V4.B16        // 441ca24e
 	VMOV	V20.S[0], V20         // 9406045e
+	VDUP	V20.S[0], V20         // 9406045e
 	VMOV	V12.D[0], V12.D[1]    // 8c05186e
 	VMOV	V10.S[0], V12.S[1]    // 4c050c6e
 	VMOV	V9.H[0], V12.H[1]     // 2c05066e
diff --git a/src/cmd/asm/internal/asm/testdata/arm64enc.s b/src/cmd/asm/internal/asm/testdata/arm64enc.s
index f71f7b0484..a29862822d 100644
--- a/src/cmd/asm/internal/asm/testdata/arm64enc.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64enc.s
@@ -669,6 +669,7 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$-8
    VCMEQ V24.S4, V13.S4, V12.S4                                // ac8db86e
    VCNT V13.B8, V11.B8                                         // ab59200e
    VMOV V31.B[15], V18                                         // f2071f5e
+   VDUP V31.B[15], V18                                         // f2071f5e
    VDUP V31.B[13], V20.B16                                     // f4071b4e
    VEOR V4.B8, V18.B8, V7.B8                                   // 471e242e
    VEXT $4, V2.B8, V1.B8, V3.B8                                // 2320022e
@@ -700,6 +701,7 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$-8
    //TODO FMOVS.W 71(R29), F28                                 // bc7f44bc
    FMOVS 6160(R4), F23                                         // 971058bd
    VMOV V18.B[10], V27                                         // 5b06155e
+   VDUP V18.B[10], V27                                         // 5b06155e
    VMOV V12.B[2], V28.B[12]                                    // 9c15196e
    VMOV R30, V4.B[13]                                          // c41f1b4e
    VMOV V2.B16, V4.B16                                         // 441ca24e
diff --git a/src/cmd/internal/obj/arm64/asm7.go b/src/cmd/internal/obj/arm64/asm7.go
index 275799aad3..20f1843951 100644
--- a/src/cmd/internal/obj/arm64/asm7.go
+++ b/src/cmd/internal/obj/arm64/asm7.go
@@ -501,6 +501,8 @@ var optab = []Optab{
 	{AVMOV, C_REG, C_NONE, C_NONE, C_ELEM, 78, 4, 0, 0, 0},
 	{AVMOV, C_ARNG, C_NONE, C_NONE, C_ARNG, 83, 4, 0, 0, 0},
 	{AVDUP, C_ELEM, C_NONE, C_NONE, C_ARNG, 79, 4, 0, 0, 0},
+	{AVDUP, C_ELEM, C_NONE, C_NONE, C_VREG, 80, 4, 0, 0, 0},
+	{AVDUP, C_REG, C_NONE, C_NONE, C_ARNG, 82, 4, 0, 0, 0},
 	{AVMOVI, C_ADDCON, C_NONE, C_NONE, C_ARNG, 86, 4, 0, 0, 0},
 	{AVFMLA, C_ARNG, C_ARNG, C_NONE, C_ARNG, 72, 4, 0, 0, 0},
 	{AVEXT, C_VCON, C_ARNG, C_ARNG, C_ARNG, 94, 4, 0, 0, 0},
@@ -4653,13 +4655,13 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		o1 |= (uint32(Q&1) << 30) | (uint32(imm5&0x1f) << 16)
 		o1 |= (uint32(rf&31) << 5) | uint32(rt&31)
 
-	case 80: /* vmov V.<T>[index], Vn */
+	case 80: /* vmov/vdup V.<T>[index], Vn */
 		rf := int(p.From.Reg)
 		rt := int(p.To.Reg)
 		imm5 := 0
 		index := int(p.From.Index)
 		switch p.As {
-		case AVMOV:
+		case AVMOV, AVDUP:
 			o1 = 1<<30 | 15<<25 | 1<<10
 			switch (p.From.Reg >> 5) & 15 {
 			case ARNG_B:
@@ -4709,7 +4711,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		o1 = c.maskOpvldvst(p, o1)
 		o1 |= uint32(r&31) << 5
 
-	case 82: /* vmov Rn, Vd.<T> */
+	case 82: /* vmov/vdup Rn, Vd.<T> */
 		rf := int(p.From.Reg)
 		rt := int(p.To.Reg)
 		o1 = 7<<25 | 3<<10
@@ -4737,7 +4739,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			Q = 1
 			imm5 = 2
 		default:
-			c.ctxt.Diag("invalid arrangement on VMOV Rn, Vd.<T>: %v\n", p)
+			c.ctxt.Diag("invalid arrangement: %v\n", p)
 		}
 		o1 |= (Q & 1 << 30) | (imm5 & 0x1f << 16)
 		o1 |= (uint32(rf&31) << 5) | uint32(rt&31)