From ede46886e9cf7f6457781baecb5aad29f151033f Mon Sep 17 00:00:00 2001
From: WANG Xuerui <git@xen0n.name>
Date: Mon, 20 Mar 2023 21:29:43 +0800
Subject: [PATCH] cmd/asm, cmd/internal/obj/loong64: implement {8,16}-bit sign
 extensions with EXTW{B,H}

Updates #59120

Change-Id: Ia7dd0dfe20c0ea3e64889e2b38c6b2118b50d56e
---
 .../asm/internal/asm/testdata/loong64enc1.s    |  2 ++
 .../asm/internal/asm/testdata/loong64enc2.s    |  2 --
 src/cmd/internal/obj/loong64/asm.go            | 18 ++++++++++--------
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/cmd/asm/internal/asm/testdata/loong64enc1.s b/src/cmd/asm/internal/asm/testdata/loong64enc1.s
index 2cc83bcdba2450..75ba0cd890d493 100644
--- a/src/cmd/asm/internal/asm/testdata/loong64enc1.s
+++ b/src/cmd/asm/internal/asm/testdata/loong64enc1.s
@@ -20,6 +20,8 @@ lable2:
 	MOVW	$4096, R4		// 24000014
 	MOVV	$65536, R4		// 04020014
 	MOVV	$4096, R4		// 24000014
+	MOVB	R4, R5			// 855c0000
+	MOVH	R4, R5			// 85580000
 	MOVW	R4, R5			// 85001700
 	MOVV	R4, R5			// 85001500
 	MOVBU	R4, R5			// 85fc4303
diff --git a/src/cmd/asm/internal/asm/testdata/loong64enc2.s b/src/cmd/asm/internal/asm/testdata/loong64enc2.s
index 3b5e3cb81ae897..58f54ad579e021 100644
--- a/src/cmd/asm/internal/asm/testdata/loong64enc2.s
+++ b/src/cmd/asm/internal/asm/testdata/loong64enc2.s
@@ -5,7 +5,6 @@
 #include "../../../../../runtime/textflag.h"
 
 TEXT asmtest(SB),DUPOK|NOSPLIT,$0
-	MOVB	R4, R5			// 85e04000a5e04800
 	MOVWU	R4, R5			// 85804100a5804500
 	MOVW	$74565, R4		// 4402001484148d03
 	MOVW	$4097, R4		// 2400001484048003
@@ -59,7 +58,6 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	XOR	$4096, R4		// 3e00001484f81500
 	XOR	$-1, R4, R5		// 1efcbf0285f81500
 	XOR	$-1, R4			// 1efcbf0284f81500
-	MOVH	R4, R5			// 85c04000a5c04800
 
 	// relocation	instructions
 	MOVW	R4, name(SB)		// 1e00001cc4038029
diff --git a/src/cmd/internal/obj/loong64/asm.go b/src/cmd/internal/obj/loong64/asm.go
index c375aaa0eeb57a..d4b2e1e7da9ab0 100644
--- a/src/cmd/internal/obj/loong64/asm.go
+++ b/src/cmd/internal/obj/loong64/asm.go
@@ -52,7 +52,7 @@ var optab = []Optab{
 
 	{AMOVW, C_REG, C_NONE, C_NONE, C_REG, C_NONE, 1, 4, 0, 0},
 	{AMOVV, C_REG, C_NONE, C_NONE, C_REG, C_NONE, 1, 4, 0, 0},
-	{AMOVB, C_REG, C_NONE, C_NONE, C_REG, C_NONE, 12, 8, 0, NOTUSETMP},
+	{AMOVB, C_REG, C_NONE, C_NONE, C_REG, C_NONE, 12, 4, 0, NOTUSETMP},
 	{AMOVBU, C_REG, C_NONE, C_NONE, C_REG, C_NONE, 13, 4, 0, 0},
 	{AMOVWU, C_REG, C_NONE, C_NONE, C_REG, C_NONE, 14, 8, 0, NOTUSETMP},
 
@@ -1308,14 +1308,16 @@ func (c *ctxt0) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		rel.Type = objabi.R_CALLLOONG64
 
 	case 12: // movbs r,r
-		// NOTE: this case does not use REGTMP. If it ever does,
-		// remove the NOTUSETMP flag in optab.
-		v := 16
-		if p.As == AMOVB {
-			v = 24
+		var insn obj.As
+		switch p.As {
+		case AMOVB:
+			insn = AEXTWB
+		case AMOVH:
+			insn = AEXTWH
+		default:
+			c.ctxt.Diag("unexpected encoding")
 		}
-		o1 = OP_16IRR(c.opirr(ASLL), uint32(v), uint32(p.From.Reg), uint32(p.To.Reg))
-		o2 = OP_16IRR(c.opirr(ASRA), uint32(v), uint32(p.To.Reg), uint32(p.To.Reg))
+		o1 = OP_RR(c.oprr(insn), uint32(p.From.Reg), uint32(p.To.Reg))
 
 	case 13: // movbu r,r
 		if p.As == AMOVBU {