1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
package asm
//go:generate stringer -output jump_string.go -type=JumpOp
// JumpOp affect control flow.
//
// msb lsb
// +----+-+---+
// |OP |s|cls|
// +----+-+---+
type JumpOp uint8
const jumpMask OpCode = aluMask
const (
// InvalidJumpOp is returned by getters when invoked
// on non branch OpCodes
InvalidJumpOp JumpOp = 0xff
// Ja jumps by offset unconditionally
Ja JumpOp = 0x00
// JEq jumps by offset if r == imm
JEq JumpOp = 0x10
// JGT jumps by offset if r > imm
JGT JumpOp = 0x20
// JGE jumps by offset if r >= imm
JGE JumpOp = 0x30
// JSet jumps by offset if r & imm
JSet JumpOp = 0x40
// JNE jumps by offset if r != imm
JNE JumpOp = 0x50
// JSGT jumps by offset if signed r > signed imm
JSGT JumpOp = 0x60
// JSGE jumps by offset if signed r >= signed imm
JSGE JumpOp = 0x70
// Call builtin or user defined function from imm
Call JumpOp = 0x80
// Exit ends execution, with value in r0
Exit JumpOp = 0x90
// JLT jumps by offset if r < imm
JLT JumpOp = 0xa0
// JLE jumps by offset if r <= imm
JLE JumpOp = 0xb0
// JSLT jumps by offset if signed r < signed imm
JSLT JumpOp = 0xc0
// JSLE jumps by offset if signed r <= signed imm
JSLE JumpOp = 0xd0
)
// Return emits an exit instruction.
//
// Requires a return value in R0.
func Return() Instruction {
return Instruction{
OpCode: OpCode(JumpClass).SetJumpOp(Exit),
}
}
// Op returns the OpCode for a given jump source.
func (op JumpOp) Op(source Source) OpCode {
return OpCode(JumpClass).SetJumpOp(op).SetSource(source)
}
// Imm compares dst to value, and adjusts PC by offset if the condition is fulfilled.
func (op JumpOp) Imm(dst Register, value int32, label string) Instruction {
if op == Exit || op == Call || op == Ja {
return Instruction{OpCode: InvalidOpCode}
}
return Instruction{
OpCode: OpCode(JumpClass).SetJumpOp(op).SetSource(ImmSource),
Dst: dst,
Offset: -1,
Constant: int64(value),
Reference: label,
}
}
// Reg compares dst to src, and adjusts PC by offset if the condition is fulfilled.
func (op JumpOp) Reg(dst, src Register, label string) Instruction {
if op == Exit || op == Call || op == Ja {
return Instruction{OpCode: InvalidOpCode}
}
return Instruction{
OpCode: OpCode(JumpClass).SetJumpOp(op).SetSource(RegSource),
Dst: dst,
Src: src,
Offset: -1,
Reference: label,
}
}
// Label adjusts PC to the address of the label.
func (op JumpOp) Label(label string) Instruction {
if op == Call {
return Instruction{
OpCode: OpCode(JumpClass).SetJumpOp(Call),
Src: PseudoCall,
Constant: -1,
Reference: label,
}
}
return Instruction{
OpCode: OpCode(JumpClass).SetJumpOp(op),
Offset: -1,
Reference: label,
}
}
|
