cmd/intarnal/obj: add new assembly format for VANDV and VANDB on loong64

In order to make it easier to write in assembly and to be consistent
with the usage of general instructions, a new assembly format is
added for the instructions VANDV and VANDB.

It also works for instructions XVAND{V,B}, [X]V{OR,XOR,NOR,ANDN,ORN}V
and [X]V{OR,XOR,NOR}B.

Change-Id: Ia75d607ac918950e58840ec627aaf0be45d837fe
Reviewed-on: https://go-review.googlesource.com/c/go/+/671316
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

Author: sophie-zhao

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

@@ -547,12 +547,22 @@ lable2:
 	VNORV		V1, V2, V3      // 43842771
 	VANDNV		V1, V2, V3      // 43042871
 	VORNV		V1, V2, V3      // 43842871
+	VANDV		V1, V2		// 42042671
+	VORV		V1, V2		// 42842671
+	VXORV		V1, V2		// 42042771
+	VNORV		V1, V2		// 42842771
+	VANDNV		V1, V2		// 42042871
+	VORNV		V1, V2		// 42842871
 
 	// VANDB,VORB,VXORB,VNORB
 	VANDB		$0, V2, V3      // 4300d073
 	VORB		$64, V2, V3     // 4300d573
 	VXORB		$128, V2, V3    // 4300da73
 	VNORB		$255, V2, V3    // 43fcdf73
+	VANDB		$0, V2		// 4200d073
+	VORB		$64, V2		// 4200d573
+	VXORB		$128, V2	// 4200da73
+	VNORB		$255, V2	// 42fcdf73
 
 	// XVANDV,XVORV,XVXORV,XVNORV,XVANDNV,XVORNV
 	XVANDV		X1, X2, X3      // 43042675
@@ -561,12 +571,22 @@ lable2:
 	XVNORV		X1, X2, X3      // 43842775
 	XVANDNV		X1, X2, X3      // 43042875
 	XVORNV		X1, X2, X3      // 43842875
+	XVANDV		X1, X2		// 42042675
+	XVORV		X1, X2		// 42842675
+	XVXORV		X1, X2		// 42042775
+	XVNORV		X1, X2		// 42842775
+	XVANDNV		X1, X2		// 42042875
+	XVORNV		X1, X2		// 42842875
 
 	// XVANDB,XVORB,XVXORB,XVNORB
 	XVANDB		$0, X2, X3      // 4300d077
 	XVORB		$1, X2, X3      // 4304d477
 	XVXORB		$127, X2, X3    // 43fcd977
 	XVNORB		$255, X2, X3    // 43fcdf77
+	XVANDB		$0, X2		// 4200d077
+	XVORB		$1, X2		// 4204d477
+	XVXORB		$127, X2	// 42fcd977
+	XVNORB		$255, X2	// 42fcdf77
 
 	// MOVV C_DCON12_0, r
 	MOVV    $0x7a90000000000000, R4         // MOVV $8831558869273542656, R4        // 04a41e03

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

@@ -92,9 +92,13 @@ var optab = []Optab{
 	{AVSEQB, C_S5CON, C_VREG, C_NONE, C_VREG, C_NONE, 22, 4, 0, 0},
 	{AXVSEQB, C_S5CON, C_XREG, C_NONE, C_XREG, C_NONE, 22, 4, 0, 0},
 	{AVANDV, C_VREG, C_VREG, C_NONE, C_VREG, C_NONE, 2, 4, 0, 0},
+	{AVANDV, C_VREG, C_NONE, C_NONE, C_VREG, C_NONE, 2, 4, 0, 0},
 	{AXVANDV, C_XREG, C_XREG, C_NONE, C_XREG, C_NONE, 2, 4, 0, 0},
+	{AXVANDV, C_XREG, C_NONE, C_NONE, C_XREG, C_NONE, 2, 4, 0, 0},
 	{AVANDB, C_U8CON, C_VREG, C_NONE, C_VREG, C_NONE, 23, 4, 0, 0},
+	{AVANDB, C_U8CON, C_NONE, C_NONE, C_VREG, C_NONE, 23, 4, 0, 0},
 	{AXVANDB, C_U8CON, C_XREG, C_NONE, C_XREG, C_NONE, 23, 4, 0, 0},
+	{AXVANDB, C_U8CON, C_NONE, C_NONE, C_XREG, C_NONE, 23, 4, 0, 0},
 
 	{AVADDB, C_VREG, C_VREG, C_NONE, C_VREG, C_NONE, 2, 4, 0, 0},
 	{AVADDB, C_VREG, C_NONE, C_NONE, C_VREG, C_NONE, 2, 4, 0, 0},