go, math, os, reflect: support standard library for loong64

Contributors to the loong64 port are:
  Weining Lu <[email protected]>
  Lei Wang <[email protected]>
  Lingqin Gong <[email protected]>
  Xiaolin Zhao <[email protected]>
  Meidan Li <[email protected]>
  Xiaojuan Zhai <[email protected]>
  Qiyuan Pu <[email protected]>
  Guoqi Chen <[email protected]>

This port has been updated to Go 1.15.6:
  https://github.com/loongson/go

Updates #46229

Change-Id: I2ad9ed01fc913b90e75023ac0fa70de87a9f5de1
Reviewed-on: https://go-review.googlesource.com/c/go/+/342324
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Run-TryBot: Ian Lance Taylor <[email protected]>
Auto-Submit: Ian Lance Taylor <[email protected]>
Reviewed-by: Michael Knyszek <[email protected]>

Author: XiaodongLoong

src/go/types/gccgosizes.go

@@ -17,6 +17,7 @@ var gccgoArchSizes = map[string]*StdSizes{
 	"arm64":       {8, 8},
 	"arm64be":     {8, 8},
 	"ia64":        {8, 8},
+	"loong64":     {8, 8},
 	"m68k":        {4, 2},
 	"mips":        {4, 8},
 	"mipsle":      {4, 8},

src/math/big/arith_loong64.s

@@ -0,0 +1,34 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !math_big_pure_go,loong64
+
+#include "textflag.h"
+
+// This file provides fast assembly versions for the elementary
+// arithmetic operations on vectors implemented in arith.go.
+
+TEXT ·addVV(SB),NOSPLIT,$0
+	JMP ·addVV_g(SB)
+
+TEXT ·subVV(SB),NOSPLIT,$0
+	JMP ·subVV_g(SB)
+
+TEXT ·addVW(SB),NOSPLIT,$0
+	JMP ·addVW_g(SB)
+
+TEXT ·subVW(SB),NOSPLIT,$0
+	JMP ·subVW_g(SB)
+
+TEXT ·shlVU(SB),NOSPLIT,$0
+	JMP ·shlVU_g(SB)
+
+TEXT ·shrVU(SB),NOSPLIT,$0
+	JMP ·shrVU_g(SB)
+
+TEXT ·mulAddVWW(SB),NOSPLIT,$0
+	JMP ·mulAddVWW_g(SB)
+
+TEXT ·addMulVVW(SB),NOSPLIT,$0
+	JMP ·addMulVVW_g(SB)

src/os/endian_little.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 //
-//go:build 386 || amd64 || arm || arm64 || ppc64le || mips64le || mipsle || riscv64 || wasm
+//go:build 386 || amd64 || arm || arm64 || loong64 || ppc64le || mips64le || mipsle || riscv64 || wasm
 
 package os
 

src/reflect/asm_loong64.s

@@ -0,0 +1,40 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+#include "funcdata.h"
+
+#define	REGCTXT	R29
+
+// makeFuncStub is the code half of the function returned by MakeFunc.
+// See the comment on the declaration of makeFuncStub in makefunc.go
+// for more details.
+// No arg size here, runtime pulls arg map out of the func value.
+TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$40
+	NO_LOCAL_POINTERS
+	MOVV	REGCTXT, 8(R3)
+	MOVV	$argframe+0(FP), R19
+	MOVV	R19, 16(R3)
+	MOVB	R0, 40(R3)
+	ADDV	$40, R3, R19
+	MOVV	R19, 24(R3)
+	MOVV	R0, 32(R3)
+	JAL	·callReflect(SB)
+	RET
+
+// methodValueCall is the code half of the function returned by makeMethodValue.
+// See the comment on the declaration of methodValueCall in makefunc.go
+// for more details.
+// No arg size here; runtime pulls arg map out of the func value.
+TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$40
+	NO_LOCAL_POINTERS
+	MOVV	REGCTXT, 8(R3)
+	MOVV	$argframe+0(FP), R19
+	MOVV	R19, 16(R3)
+	MOVB	R0, 40(R3)
+	ADDV	$40, R3, R19
+	MOVV	R19, 24(R3)
+	MOVV	R0, 32(R3)
+	JAL	·callMethod(SB)
+	RET