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 27d318a8bb92bdc01663617b50f0a6132a6aa81d..bb1b146346191c8417e62bfcd72772ce329eef32 100644 (file)
--- 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