| // 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)} | |
| } | |