From: limeidan <limeidan@loongson.cn>
Date: Thu, 21 Aug 2025 11:46:47 +0000 (+0800)
Subject: cmd/compile: simplify zerorange on loong64
X-Git-Tag: go1.26rc1~1043
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=e0870a0a121c22899208d80e81310d247c54f198;p=gostls13.git

cmd/compile: simplify zerorange on loong64

Refer to CL 678936, we also did the same thing on loong64.

Change-Id: I156a9110a034878192f64baf8018115424aa5f0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/697957
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
---

diff --git a/src/cmd/compile/internal/loong64/ggen.go b/src/cmd/compile/internal/loong64/ggen.go
index 27d318a8bb..bb1b146346 100644
--- a/src/cmd/compile/internal/loong64/ggen.go
+++ b/src/cmd/compile/internal/loong64/ggen.go
@@ -6,49 +6,23 @@ package loong64
 
 import (
 	"cmd/compile/internal/base"
-	"cmd/compile/internal/ir"
 	"cmd/compile/internal/objw"
-	"cmd/compile/internal/types"
 	"cmd/internal/obj"
 	"cmd/internal/obj/loong64"
 )
 
 func zerorange(pp *objw.Progs, p *obj.Prog, off, cnt int64, _ *uint32) *obj.Prog {
-	if cnt == 0 {
-		return p
+	if cnt%8 != 0 {
+		panic("zeroed region not aligned")
 	}
 
 	// Adjust the frame to account for LR.
 	off += base.Ctxt.Arch.FixedFrameSize
 
-	if cnt < int64(4*types.PtrSize) {
-		for i := int64(0); i < cnt; i += int64(types.PtrSize) {
-			p = pp.Append(p, loong64.AMOVV, obj.TYPE_REG, loong64.REGZERO, 0, obj.TYPE_MEM, loong64.REGSP, off+i)
-		}
-	} else if cnt <= int64(128*types.PtrSize) {
-		p = pp.Append(p, loong64.AADDV, obj.TYPE_CONST, 0, off, obj.TYPE_REG, loong64.REGRT1, 0)
-		p.Reg = loong64.REGSP
-		p = pp.Append(p, obj.ADUFFZERO, obj.TYPE_NONE, 0, 0, obj.TYPE_MEM, 0, 0)
-		p.To.Name = obj.NAME_EXTERN
-		p.To.Sym = ir.Syms.Duffzero
-		p.To.Offset = 8 * (128 - cnt/int64(types.PtrSize))
-	} else {
-		//	ADDV	$(off), SP, r1
-		//	ADDV	$cnt, r1, r2
-		// loop:
-		//	MOVV	R0, (r1)
-		//	ADDV	$Widthptr, r1
-		//	BNE	r1, r2, loop
-		p = pp.Append(p, loong64.AADDV, obj.TYPE_CONST, 0, off, obj.TYPE_REG, loong64.REGRT1, 0)
-		p.Reg = loong64.REGSP
-		p = pp.Append(p, loong64.AADDV, obj.TYPE_CONST, 0, cnt, obj.TYPE_REG, loong64.REGRT2, 0)
-		p.Reg = loong64.REGRT1
-		p = pp.Append(p, loong64.AMOVV, obj.TYPE_REG, loong64.REGZERO, 0, obj.TYPE_MEM, loong64.REGRT1, 0)
-		loop := p
-		p = pp.Append(p, loong64.AADDV, obj.TYPE_CONST, 0, int64(types.PtrSize), obj.TYPE_REG, loong64.REGRT1, 0)
-		p = pp.Append(p, loong64.ABNE, obj.TYPE_REG, loong64.REGRT1, 0, obj.TYPE_BRANCH, 0, 0)
-		p.Reg = loong64.REGRT2
-		p.To.SetTarget(loop)
+	for cnt != 0 {
+		p = pp.Append(p, loong64.AMOVV, obj.TYPE_REG, loong64.REGZERO, 0, obj.TYPE_MEM, loong64.REGSP, off)
+		off += 8
+		cnt -= 8
 	}
 
 	return p