cmd/internal/obj/loong64: add {V,XV}ILV{L/H}.{B/H/W/D} instructions support

Go asm syntax:
	 VILV{L/H}{B/H/W/V}	VK, VJ, VD
	XVILV{L/H}{B/H/W/V}	XK, XJ, XD

Equivalent platform assembler syntax:
	 vilv{l/h}.{b/h/w/d}	vd, vj, vk
	xvilv{l/h}.{b/h/w/d}	xd, xj, xk

Change-Id: I40e21737649d9fdbbc9a423e859f4c0a56d069fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/635936
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Junyang Shao <shaojunyang@google.com>

src/cmd/asm/internal/asm/testdata/loong64enc1.s

@@ -719,3 +719,21 @@ lable2:
 	XVSUBHU		$14, X1, X2	// 22b88c76
 	XVSUBWU		$15, X1, X2	// 223c8d76
 	XVSUBVU		$16, X1, X2	// 22c08d76
+
+	// [X]VILV{L/H}{B,H,W,V} instructions
+	VILVLB		V1, V2, V3	// 43041a71
+	VILVLH		V1, V2, V3	// 43841a71
+	VILVLW		V1, V2, V3	// 43041b71
+	VILVLV		V1, V2, V3	// 43841b71
+	VILVHB		V1, V2, V3	// 43041c71
+	VILVHH		V1, V2, V3	// 43841c71
+	VILVHW		V1, V2, V3	// 43041d71
+	VILVHV		V1, V2, V3	// 43841d71
+	XVILVLB		X3, X2, X1	// 410c1a75
+	XVILVLH		X3, X2, X1	// 418c1a75
+	XVILVLW		X3, X2, X1	// 410c1b75
+	XVILVLV		X3, X2, X1	// 418c1b75
+	XVILVHB		X3, X2, X1	// 410c1c75
+	XVILVHH		X3, X2, X1	// 418c1c75
+	XVILVHW		X3, X2, X1	// 410c1d75
+	XVILVHV		X3, X2, X1	// 418c1d75

src/cmd/internal/obj/loong64/a.out.go

@@ -837,6 +837,24 @@ const (
 	AXVROTRW
 	AXVROTRV
 
+	// LSX and LASX move and shuffle instructions
+	AVILVLB
+	AVILVLH
+	AVILVLW
+	AVILVLV
+	AVILVHB
+	AVILVHH
+	AVILVHW
+	AVILVHV
+	AXVILVLB
+	AXVILVLH
+	AXVILVLW
+	AXVILVLV
+	AXVILVHB
+	AXVILVHH
+	AXVILVHW
+	AXVILVHV
+
 	ALAST
 
 	// aliases

src/cmd/internal/obj/loong64/anames.go

@@ -345,5 +345,21 @@ var Anames = []string{
 	"XVROTRH",
 	"XVROTRW",
 	"XVROTRV",
+	"VILVLB",
+	"VILVLH",
+	"VILVLW",
+	"VILVLV",
+	"VILVHB",
+	"VILVHH",
+	"VILVHW",
+	"VILVHV",
+	"XVILVLB",
+	"XVILVLH",
+	"XVILVLW",
+	"XVILVLV",
+	"XVILVHB",
+	"XVILVHH",
+	"XVILVHW",
+	"XVILVHV",
 	"LAST",
 }

src/cmd/internal/obj/loong64/asm.go

@@ -1539,11 +1539,27 @@ func buildop(ctxt *obj.Link) {
 			opset(AVSEQH, r0)
 			opset(AVSEQW, r0)
 			opset(AVSEQV, r0)
+			opset(AVILVLB, r0)
+			opset(AVILVLH, r0)
+			opset(AVILVLW, r0)
+			opset(AVILVLV, r0)
+			opset(AVILVHB, r0)
+			opset(AVILVHH, r0)
+			opset(AVILVHW, r0)
+			opset(AVILVHV, r0)
 
 		case AXVSEQB:
 			opset(AXVSEQH, r0)
 			opset(AXVSEQW, r0)
 			opset(AXVSEQV, r0)
+			opset(AXVILVLB, r0)
+			opset(AXVILVLH, r0)
+			opset(AXVILVLW, r0)
+			opset(AXVILVLV, r0)
+			opset(AXVILVHB, r0)
+			opset(AXVILVHH, r0)
+			opset(AXVILVHW, r0)
+			opset(AXVILVHV, r0)
 
 		case AVPCNTB:
 			opset(AVPCNTH, r0)
@@ -2862,6 +2878,38 @@ func (c *ctxt0) oprrr(a obj.As) uint32 {
 		return 0xe81b << 15 // xvsub.d
 	case AXVSUBQ:
 		return 0xea5b << 15 // xvsub.q
+	case AVILVLB:
+		return 0xe234 << 15 // vilvl.b
+	case AVILVLH:
+		return 0xe235 << 15 // vilvl.h
+	case AVILVLW:
+		return 0xe236 << 15 // vilvl.w
+	case AVILVLV:
+		return 0xe237 << 15 // vilvl.d
+	case AVILVHB:
+		return 0xe238 << 15 // vilvh.b
+	case AVILVHH:
+		return 0xe239 << 15 // vilvh.h
+	case AVILVHW:
+		return 0xe23a << 15 // vilvh.w
+	case AVILVHV:
+		return 0xe23b << 15 // vilvh.d
+	case AXVILVLB:
+		return 0xea34 << 15 // xvilvl.b
+	case AXVILVLH:
+		return 0xea35 << 15 // xvilvl.h
+	case AXVILVLW:
+		return 0xea36 << 15 // xvilvl.w
+	case AXVILVLV:
+		return 0xea37 << 15 // xvilvl.d
+	case AXVILVHB:
+		return 0xea38 << 15 // xvilvh.b
+	case AXVILVHH:
+		return 0xea39 << 15 // xvilvh.h
+	case AXVILVHW:
+		return 0xea3a << 15 // xvilvh.w
+	case AXVILVHV:
+		return 0xea3b << 15 // xvilvh.d
 	}
 
 	if a < 0 {