1// Copyright 2016 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// s390x 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/s390x"
14)
15
16func jumpS390x(word string) bool {
17	switch word {
18	case "BC",
19		"BCL",
20		"BEQ",
21		"BGE",
22		"BGT",
23		"BL",
24		"BLE",
25		"BLEU",
26		"BLT",
27		"BLTU",
28		"BNE",
29		"BR",
30		"BVC",
31		"BVS",
32		"CMPBEQ",
33		"CMPBGE",
34		"CMPBGT",
35		"CMPBLE",
36		"CMPBLT",
37		"CMPBNE",
38		"CMPUBEQ",
39		"CMPUBGE",
40		"CMPUBGT",
41		"CMPUBLE",
42		"CMPUBLT",
43		"CMPUBNE",
44		"CALL",
45		"JMP":
46		return true
47	}
48	return false
49}
50
51// IsS390xCMP reports whether the op (as defined by an s390x.A* constant) is
52// one of the CMP instructions that require special handling.
53func IsS390xCMP(op obj.As) bool {
54	switch op {
55	case s390x.ACMP, s390x.ACMPU, s390x.ACMPW, s390x.ACMPWU:
56		return true
57	}
58	return false
59}
60
61// IsS390xNEG reports whether the op (as defined by an s390x.A* constant) is
62// one of the NEG-like instructions that require special handling.
63func IsS390xNEG(op obj.As) bool {
64	switch op {
65	case s390x.ANEG, s390x.ANEGW:
66		return true
67	}
68	return false
69}
70
71func s390xRegisterNumber(name string, n int16) (int16, bool) {
72	switch name {
73	case "AR":
74		if 0 <= n && n <= 15 {
75			return s390x.REG_AR0 + n, true
76		}
77	case "F":
78		if 0 <= n && n <= 15 {
79			return s390x.REG_F0 + n, true
80		}
81	case "R":
82		if 0 <= n && n <= 15 {
83			return s390x.REG_R0 + n, true
84		}
85	case "V":
86		if 0 <= n && n <= 31 {
87			return s390x.REG_V0 + n, true
88		}
89	}
90	return 0, false
91}
92