// Copyright 2025 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.

package asmgen

import "fmt"

var Arch386 = &Arch{

Name: "386",

WordBits: 32,

WordBytes: 4,

regs: []string{

"BX", "SI", "DI", "BP",

"CX", "DX", "AX", // last, to leave available for hinted allocation

},

op3: x86Op3,

hint: x86Hint,

memOK: true,

subCarryIsBorrow: true,

maxColumns: 1, // not enough registers for more

// Note: It would be nice to not set memIndex and then

// delete all the code in pipe.go that supports it.

// But a few routines, notably lshVU and mulAddVWW,

// benefit dramatically from the use of index registers.

// Perhaps some day we will decide 386 performance

// does not matter enough to keep this code.

memIndex: _386MemIndex,

mov: "MOVL",

adds: "ADDL",

adcs: "ADCL",

subs: "SUBL",

sbcs: "SBBL",

lsh: "SHLL",

lshd: "SHLL",

rsh: "SHRL",

rshd: "SHRL",

and: "ANDL",

or: "ORL",

xor: "XORL",

neg: "NEGL",

lea: "LEAL",

mulWideF: x86MulWide,

addWords: "LEAL (%[2]s)(%[1]s*4), %[3]s",

jmpZero: "TESTL %[1]s, %[1]s; JZ %[2]s",

jmpNonZero: "TESTL %[1]s, %[1]s; JNZ %[2]s",

loopBottom: "SUBL $1, %[1]s; JNZ %[2]s",

loopBottomNeg: "ADDL $1, %[1]s; JNZ %[2]s",

}

func _386MemIndex(a *Asm, off int, ix Reg, p RegPtr) Reg {

return Reg{fmt.Sprintf("%d(%s)(%s*%d)", off, p, ix, a.Arch.WordBytes)}

}