cmd/internal/obj/loong64: add [X]VFRINT[{RNE/RZ/RP/RM}].{S/D} instructions

Go asm syntax:
	 VFRINT[{RNE/RZ/RP/RM}]{F/D}	VJ, VD
	XVFRINT[{RNE/RZ/RP/RM}]{F/D}	XJ, XD

Equivalent platform assembler syntax:
	 vfrint[{rne/rz/rp/rm}].{s/d}	vd, vj
	xvfrint[{rne/rz/rp/rm}].{s/d}	xd, xj

Change-Id: I4ed8782289ae3329d675239f799d5f75b1adc4ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/670235
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>

Author: sophie-zhao

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

@@ -964,3 +964,25 @@ lable2:
 	XVSETALLNEH	X1, FCC0	// 20b49c76
 	XVSETALLNEW	X1, FCC0	// 20b89c76
 	XVSETALLNEV	X1, FCC0	// 20bc9c76
+
+	// [X]VFRINT[{RNE/RZ/RP/RM}].{S/D} instructions
+	VFRINTRNEF	V1, V2		// 22749d72
+	VFRINTRNED	V1, V2		// 22789d72
+	VFRINTRZF	V1, V2		// 22649d72
+	VFRINTRZD	V1, V2		// 22689d72
+	VFRINTRPF	V1, V2		// 22549d72
+	VFRINTRPD	V1, V2		// 22589d72
+	VFRINTRMF	V1, V2		// 22449d72
+	VFRINTRMD	V1, V2		// 22489d72
+	VFRINTF		V1, V2		// 22349d72
+	VFRINTD		V1, V2		// 22389d72
+	XVFRINTRNEF	X1, X2		// 22749d76
+	XVFRINTRNED	X1, X2		// 22789d76
+	XVFRINTRZF	X1, X2		// 22649d76
+	XVFRINTRZD	X1, X2		// 22689d76
+	XVFRINTRPF	X1, X2		// 22549d76
+	XVFRINTRPD	X1, X2		// 22589d76
+	XVFRINTRMF	X1, X2		// 22449d76
+	XVFRINTRMD	X1, X2		// 22489d76
+	XVFRINTF	X1, X2		// 22349d76
+	XVFRINTD	X1, X2		// 22389d76

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

@@ -950,6 +950,28 @@ const (
 	AXVFRSQRTF
 	AXVFRSQRTD
 
+	// LSX and LASX floating point conversion instructions
+	AVFRINTRNEF
+	AVFRINTRNED
+	AVFRINTRZF
+	AVFRINTRZD
+	AVFRINTRPF
+	AVFRINTRPD
+	AVFRINTRMF
+	AVFRINTRMD
+	AVFRINTF
+	AVFRINTD
+	AXVFRINTRNEF
+	AXVFRINTRNED
+	AXVFRINTRZF
+	AXVFRINTRZD
+	AXVFRINTRPF
+	AXVFRINTRPD
+	AXVFRINTRMF
+	AXVFRINTRMD
+	AXVFRINTF
+	AXVFRINTD
+
 	// LSX and LASX integer neg instructions
 	AVNEGB
 	AVNEGH

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

@@ -1722,6 +1722,16 @@ func buildop(ctxt *obj.Link) {
 			opset(AVNEGH, r0)
 			opset(AVNEGW, r0)
 			opset(AVNEGV, r0)
+			opset(AVFRINTRNEF, r0)
+			opset(AVFRINTRNED, r0)
+			opset(AVFRINTRZF, r0)
+			opset(AVFRINTRZD, r0)
+			opset(AVFRINTRPF, r0)
+			opset(AVFRINTRPD, r0)
+			opset(AVFRINTRMF, r0)
+			opset(AVFRINTRMD, r0)
+			opset(AVFRINTF, r0)
+			opset(AVFRINTD, r0)
 
 		case AXVPCNTB:
 			opset(AXVPCNTH, r0)
@@ -1737,6 +1747,16 @@ func buildop(ctxt *obj.Link) {
 			opset(AXVNEGH, r0)
 			opset(AXVNEGW, r0)
 			opset(AXVNEGV, r0)
+			opset(AXVFRINTRNEF, r0)
+			opset(AXVFRINTRNED, r0)
+			opset(AXVFRINTRZF, r0)
+			opset(AXVFRINTRZD, r0)
+			opset(AXVFRINTRPF, r0)
+			opset(AXVFRINTRPD, r0)
+			opset(AXVFRINTRMF, r0)
+			opset(AXVFRINTRMD, r0)
+			opset(AXVFRINTF, r0)
+			opset(AXVFRINTD, r0)
 
 		case AVADDB:
 			opset(AVADDH, r0)
@@ -3583,6 +3603,46 @@ func (c *ctxt0) oprr(a obj.As) uint32 {
 		return 0x1da70e << 10 // xvneg.w
 	case AXVNEGV:
 		return 0x1da70f << 10 // xvneg.d
+	case AVFRINTRNEF:
+		return 0x1ca75d << 10 // vfrintrne.s
+	case AVFRINTRNED:
+		return 0x1ca75e << 10 // vfrintrne.d
+	case AVFRINTRZF:
+		return 0x1ca759 << 10 // vfrintrz.s
+	case AVFRINTRZD:
+		return 0x1ca75a << 10 // vfrintrz.d
+	case AVFRINTRPF:
+		return 0x1ca755 << 10 // vfrintrp.s
+	case AVFRINTRPD:
+		return 0x1ca756 << 10 // vfrintrp.d
+	case AVFRINTRMF:
+		return 0x1ca751 << 10 // vfrintrm.s
+	case AVFRINTRMD:
+		return 0x1ca752 << 10 // vfrintrm.d
+	case AVFRINTF:
+		return 0x1ca74d << 10 // vfrint.s
+	case AVFRINTD:
+		return 0x1ca74e << 10 // vfrint.d
+	case AXVFRINTRNEF:
+		return 0x1da75d << 10 // xvfrintrne.s
+	case AXVFRINTRNED:
+		return 0x1da75e << 10 // xvfrintrne.d
+	case AXVFRINTRZF:
+		return 0x1da759 << 10 // xvfrintrz.s
+	case AXVFRINTRZD:
+		return 0x1da75a << 10 // xvfrintrz.d
+	case AXVFRINTRPF:
+		return 0x1da755 << 10 // xvfrintrp.s
+	case AXVFRINTRPD:
+		return 0x1da756 << 10 // xvfrintrp.d
+	case AXVFRINTRMF:
+		return 0x1da751 << 10 // xvfrintrm.s
+	case AXVFRINTRMD:
+		return 0x1da752 << 10 // xvfrintrm.d
+	case AXVFRINTF:
+		return 0x1da74d << 10 // xvfrint.s
+	case AXVFRINTD:
+		return 0x1da74e << 10 // xvfrint.d
 	case AVSETEQV:
 		return 0x1ca726<<10 | 0x0<<3 // vseteqz.v
 	case AVSETNEV: