runtime, cmd/compile, cmd/internal/obj: remove duff support for loong64

Change-Id: I44d6452933c8010f7dfbf821a32053f9d1cf151e
Reviewed-on: https://go-review.googlesource.com/c/go/+/700096
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: sophie zhao <zhaoxiaolin@loongson.cn>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>

3 files changed, 4 insertions, 52 deletions

diff --git a/src/cmd/internal/obj/loong64/a.out.go b/src/cmd/internal/obj/loong64/a.out.go
index 8e651cdfef..7ab85a2f23 100644
--- a/src/cmd/internal/obj/loong64/a.out.go
+++ b/src/cmd/internal/obj/loong64/a.out.go
@@ -225,8 +225,6 @@ const (
 	REGZERO = REG_R0 // set to zero
 	REGLINK = REG_R1
 	REGSP   = REG_R3
-	REGRT1  = REG_R20 // reserved for runtime, duffzero and duffcopy
-	REGRT2  = REG_R21 // reserved for runtime, duffcopy
 	REGCTXT = REG_R29 // context for closures
 	REGG    = REG_R22 // G in loong64
 	REGTMP  = REG_R30 // used by the assembler
diff --git a/src/cmd/internal/obj/loong64/asm.go b/src/cmd/internal/obj/loong64/asm.go
index 35b33b9376..848d77fd0d 100644
--- a/src/cmd/internal/obj/loong64/asm.go
+++ b/src/cmd/internal/obj/loong64/asm.go
@@ -440,8 +440,6 @@ var optab = []Optab{
 	{obj.ANOP, C_DCON, C_NONE, C_NONE, C_NONE, C_NONE, 0, 0, 0, 0},  // nop variants, see #40689
 	{obj.ANOP, C_REG, C_NONE, C_NONE, C_NONE, C_NONE, 0, 0, 0, 0},
 	{obj.ANOP, C_FREG, C_NONE, C_NONE, C_NONE, C_NONE, 0, 0, 0, 0},
-	{obj.ADUFFZERO, C_NONE, C_NONE, C_NONE, C_BRAN, C_NONE, 11, 4, 0, 0}, // same as AJMP
-	{obj.ADUFFCOPY, C_NONE, C_NONE, C_NONE, C_BRAN, C_NONE, 11, 4, 0, 0}, // same as AJMP
 }
 
 var atomicInst = map[obj.As]uint32{
@@ -1526,9 +1524,7 @@ func buildop(ctxt *obj.Link) {
 			obj.ATEXT,
 			obj.AFUNCDATA,
 			obj.APCALIGN,
-			obj.APCDATA,
-			obj.ADUFFZERO,
-			obj.ADUFFCOPY:
+			obj.APCDATA:
 			break
 
 		case ARDTIMELW:
@@ -4040,9 +4036,7 @@ func (c *ctxt0) opirr(a obj.As) uint32 {
 
 	case AJMP:
 		return 0x14 << 26
-	case AJAL,
-		obj.ADUFFZERO,
-		obj.ADUFFCOPY:
+	case AJAL:
 		return 0x15 << 26
 
 	case AJIRL:
diff --git a/src/cmd/internal/obj/loong64/obj.go b/src/cmd/internal/obj/loong64/obj.go
index a1eb786da3..a97217d316 100644
--- a/src/cmd/internal/obj/loong64/obj.go
+++ b/src/cmd/internal/obj/loong64/obj.go
@@ -17,11 +17,7 @@ import (
 func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 	// Rewrite JMP/JAL to symbol as TYPE_BRANCH.
 	switch p.As {
-	case AJMP,
-		AJAL,
-		ARET,
-		obj.ADUFFZERO,
-		obj.ADUFFCOPY:
+	case AJMP, AJAL, ARET:
 		if p.To.Sym != nil {
 			p.To.Type = obj.TYPE_BRANCH
 		}
@@ -93,40 +89,6 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 }
 
 func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
-	//     ADUFFxxx $offset
-	// becomes
-	//     MOVV runtime.duffxxx@GOT, REGTMP
-	//     ADD $offset, REGTMP
-	//     JAL REGTMP
-	if p.As == obj.ADUFFCOPY || p.As == obj.ADUFFZERO {
-		var sym *obj.LSym
-		if p.As == obj.ADUFFZERO {
-			sym = ctxt.LookupABI("runtime.duffzero", obj.ABIInternal)
-		} else {
-			sym = ctxt.LookupABI("runtime.duffcopy", obj.ABIInternal)
-		}
-		offset := p.To.Offset
-		p.As = AMOVV
-		p.From.Type = obj.TYPE_MEM
-		p.From.Sym = sym
-		p.From.Name = obj.NAME_GOTREF
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REGTMP
-		p.To.Name = obj.NAME_NONE
-		p.To.Offset = 0
-		p.To.Sym = nil
-		p1 := obj.Appendp(p, newprog)
-		p1.As = AADDV
-		p1.From.Type = obj.TYPE_CONST
-		p1.From.Offset = offset
-		p1.To.Type = obj.TYPE_REG
-		p1.To.Reg = REGTMP
-		p2 := obj.Appendp(p1, newprog)
-		p2.As = AJAL
-		p2.To.Type = obj.TYPE_MEM
-		p2.To.Reg = REGTMP
-	}
-
 	// We only care about global data: NAME_EXTERN means a global
 	// symbol in the Go sense, and p.Sym.Local is true for a few
 	// internally defined symbols.
@@ -256,9 +218,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 				}
 			}
 
-		case AJAL,
-			obj.ADUFFZERO,
-			obj.ADUFFCOPY:
+		case AJAL:
 			c.cursym.Func().Text.Mark &^= LEAF
 			fallthrough