1// Copyright 2015 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// This file encapsulates some of the odd characteristics of the
6// MIPS (MIPS64) instruction set, to minimize its interaction
7// with the core of the assembler.
8
9package arch
10
11import (
12	"cmd/internal/obj"
13	"cmd/internal/obj/mips"
14)
15
16func jumpMIPS(word string) bool {
17	switch word {
18	case "BEQ", "BFPF", "BFPT", "BGEZ", "BGEZAL", "BGTZ", "BLEZ", "BLTZ", "BLTZAL", "BNE", "JMP", "JAL", "CALL":
19		return true
20	}
21	return false
22}
23
24// IsMIPSCMP reports whether the op (as defined by an mips.A* constant) is
25// one of the CMP instructions that require special handling.
26func IsMIPSCMP(op obj.As) bool {
27	switch op {
28	case mips.ACMPEQF, mips.ACMPEQD, mips.ACMPGEF, mips.ACMPGED,
29		mips.ACMPGTF, mips.ACMPGTD:
30		return true
31	}
32	return false
33}
34
35// IsMIPSMUL reports whether the op (as defined by an mips.A* constant) is
36// one of the MUL/DIV/REM/MADD/MSUB instructions that require special handling.
37func IsMIPSMUL(op obj.As) bool {
38	switch op {
39	case mips.AMUL, mips.AMULU, mips.AMULV, mips.AMULVU,
40		mips.ADIV, mips.ADIVU, mips.ADIVV, mips.ADIVVU,
41		mips.AREM, mips.AREMU, mips.AREMV, mips.AREMVU,
42		mips.AMADD, mips.AMSUB:
43		return true
44	}
45	return false
46}
47
48func mipsRegisterNumber(name string, n int16) (int16, bool) {
49	switch name {
50	case "F":
51		if 0 <= n && n <= 31 {
52			return mips.REG_F0 + n, true
53		}
54	case "FCR":
55		if 0 <= n && n <= 31 {
56			return mips.REG_FCR0 + n, true
57		}
58	case "M":
59		if 0 <= n && n <= 31 {
60			return mips.REG_M0 + n, true
61		}
62	case "R":
63		if 0 <= n && n <= 31 {
64			return mips.REG_R0 + n, true
65		}
66	case "W":
67		if 0 <= n && n <= 31 {
68			return mips.REG_W0 + n, true
69		}
70	}
71	return 0, false
72}
73