base64-ng 2.0.0

no_std-first Base64 encoding and decoding with strict APIs and a security-heavy release process
Documentation 
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
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218

//! Isolated RVV 1.0 assembly leaves.

core::arch::global_asm!(
    r#"
    .option push
    .option arch, +a, +v

    .macro base64_ng_rvv_clear
        li t0, -1
        vsetvli zero, t0, e8, m1, ta, ma
        vmv.v.i v0, 0
        vmv.v.i v1, 0
        vmv.v.i v2, 0
        vmv.v.i v3, 0
        vmv.v.i v4, 0
        vmv.v.i v5, 0
        vmv.v.i v6, 0
        vmv.v.i v7, 0
        vmv.v.i v8, 0
        vmv.v.i v9, 0
        vmv.v.i v10, 0
        vmv.v.i v11, 0
        vmv.v.i v12, 0
        vmv.v.i v13, 0
        vmv.v.i v14, 0
        vmv.v.i v15, 0
    .endm

    .macro base64_ng_rvv_encode_map value, scratch, delta62, delta63
        vmv.v.v \scratch, \value
        vadd.vx \value, \value, t0
        vmsgeu.vx v0, \scratch, t1
        vadd.vi \value, \value, 6, v0.t
        vmsgeu.vx v0, \scratch, t2
        vsub.vx \value, \value, t3, v0.t
        vmseq.vx v0, \scratch, t4
        li t5, \delta62
        vadd.vx \value, \value, t5, v0.t
        vmseq.vx v0, \scratch, t6
        li t5, \delta63
        vadd.vx \value, \value, t5, v0.t
    .endm

    .macro base64_ng_rvv_encode name, delta62, delta63
        .p2align 2
        .global \name
        .hidden \name
        .type \name, @function
    \name:
        .cfi_startproc
        li t1, 26
        li t2, 52
        li t3, 75
        li t4, 62
        li t6, 63
    .Lbase64_ng_rvv_encode_loop_\@:
        vsetvli a3, a2, e8, m1, ta, ma
        vlseg3e8.v v1, (a0)

        vsrl.vi v4, v1, 2
        vand.vi v5, v1, 3
        vsll.vi v5, v5, 4
        vsrl.vi v8, v2, 4
        vor.vv v5, v5, v8
        vand.vi v6, v2, 15
        vsll.vi v6, v6, 2
        vsrl.vi v8, v3, 6
        vor.vv v6, v6, v8
        li t0, 63
        vand.vx v7, v3, t0

        li t0, 65
        base64_ng_rvv_encode_map v4, v8, \delta62, \delta63
        base64_ng_rvv_encode_map v5, v8, \delta62, \delta63
        base64_ng_rvv_encode_map v6, v8, \delta62, \delta63
        base64_ng_rvv_encode_map v7, v8, \delta62, \delta63
        vsseg4e8.v v4, (a1)

        slli a4, a3, 1
        add a4, a4, a3
        add a0, a0, a4
        slli a4, a3, 2
        add a1, a1, a4
        sub a2, a2, a3
        bnez a2, .Lbase64_ng_rvv_encode_loop_\@

        base64_ng_rvv_clear
        ret
        .cfi_endproc
        .size \name, .-\name
    .endm

    .macro base64_ng_rvv_decode_map ascii, value, scratch, special62, special63
        vsub.vx \value, \ascii, t0
        vmsgeu.vx v0, \ascii, t1
        vsub.vx \scratch, \ascii, t2
        vmerge.vvm \value, \value, \scratch, v0
        vmsltu.vx v0, \ascii, t3
        vadd.vi \scratch, \ascii, 4
        vmerge.vvm \value, \value, \scratch, v0
        vmseq.vx v0, \ascii, \special62
        li t6, 62
        vmv.v.x \scratch, t6
        vmerge.vvm \value, \value, \scratch, v0
        vmseq.vx v0, \ascii, \special63
        li t6, 63
        vmv.v.x \scratch, t6
        vmerge.vvm \value, \value, \scratch, v0
    .endm

    .macro base64_ng_rvv_decode name, ascii62, ascii63
        .p2align 2
        .global \name
        .hidden \name
        .type \name, @function
    \name:
        .cfi_startproc
        li t0, 65
        li t1, 97
        li t2, 71
        li t3, 58
        li t4, \ascii62
        li t5, \ascii63
    .Lbase64_ng_rvv_decode_loop_\@:
        vsetvli a3, a2, e8, m1, ta, ma
        vlseg4e8.v v1, (a0)

        base64_ng_rvv_decode_map v1, v5, v9, t4, t5
        base64_ng_rvv_decode_map v2, v6, v9, t4, t5
        base64_ng_rvv_decode_map v3, v7, v9, t4, t5
        base64_ng_rvv_decode_map v4, v8, v9, t4, t5

        vsll.vi v10, v5, 2
        vsrl.vi v12, v6, 4
        vor.vv v10, v10, v12
        vsll.vi v11, v6, 4
        vsrl.vi v12, v7, 2
        vor.vv v11, v11, v12
        vsll.vi v12, v7, 6
        vor.vv v12, v12, v8
        vsseg3e8.v v10, (a1)

        slli a4, a3, 2
        add a0, a0, a4
        slli a4, a3, 1
        add a4, a4, a3
        add a1, a1, a4
        sub a2, a2, a3
        bnez a2, .Lbase64_ng_rvv_decode_loop_\@

        base64_ng_rvv_clear
        ret
        .cfi_endproc
        .size \name, .-\name
    .endm

    base64_ng_rvv_encode base64_ng_rvv_encode_standard_quanta, -15, -12
    base64_ng_rvv_encode base64_ng_rvv_encode_url_safe_quanta, -13, 36
    base64_ng_rvv_decode base64_ng_rvv_decode_standard_quanta, 43, 47
    base64_ng_rvv_decode base64_ng_rvv_decode_url_safe_quanta, 45, 95

    .p2align 2
    .global base64_ng_rvv_vlenb
    .hidden base64_ng_rvv_vlenb
    .type base64_ng_rvv_vlenb, @function
base64_ng_rvv_vlenb:
    .cfi_startproc
    vsetvli zero, zero, e8, m1, ta, ma
    csrr a0, vlenb
    ret
    .cfi_endproc
    .size base64_ng_rvv_vlenb, .-base64_ng_rvv_vlenb

    .p2align 2
    .global base64_ng_rvv_signal_context_round_trip
    .hidden base64_ng_rvv_signal_context_round_trip
    .type base64_ng_rvv_signal_context_round_trip, @function
base64_ng_rvv_signal_context_round_trip:
    .cfi_startproc
    mv t1, a0
    mv t2, a1
    mv t3, a2
    vsetivli zero, 16, e8, m1, ta, ma
    li t0, 90
    vmv.v.x v8, t0
    li t0, 1
    amoswap.w.rl zero, t0, (t2)
    li t0, 250000000
.Lbase64_ng_rvv_signal_wait:
    amoadd.w.aq t4, zero, (t3)
    bnez t4, .Lbase64_ng_rvv_signal_done
    addi t0, t0, -1
    bnez t0, .Lbase64_ng_rvv_signal_wait
.Lbase64_ng_rvv_signal_done:
    amoswap.w.rl zero, zero, (t2)
    vse8.v v8, (t1)
    base64_ng_rvv_clear
    ret
    .cfi_endproc
    .size base64_ng_rvv_signal_context_round_trip, .-base64_ng_rvv_signal_context_round_trip

    .p2align 2
    .global base64_ng_rvv_signal_clobber
    .hidden base64_ng_rvv_signal_clobber
    .type base64_ng_rvv_signal_clobber, @function
base64_ng_rvv_signal_clobber:
    .cfi_startproc
    vsetivli zero, 16, e8, m1, ta, ma
    li t0, 165
    vmv.v.x v8, t0
    ret
    .cfi_endproc
    .size base64_ng_rvv_signal_clobber, .-base64_ng_rvv_signal_clobber

    .option pop
    "#,
    options(raw)
);