aboutsummaryrefslogtreecommitdiff
path: root/model/riscv_insts_vext_vset.sail
blob: 9600362370536b06908923bd7453e8ceb37b03f5 (plain)
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
/*=================================================================================*/
/*  Copyright (c) 2021-2023                                                        */
/*    Authors from RIOS Lab, Tsinghua University:                                  */
/*      Xinlai Wan <xinlai.w@rioslab.org>                                          */
/*      Xi Wang <xi.w@rioslab.org>                                                 */
/*      Yifei Zhu <yifei.z@rioslab.org>                                            */
/*      Shenwei Hu <shenwei.h@rioslab.org>                                         */
/*      Kalvin Vu                                                                  */
/*    Other contributors:                                                          */
/*      Jessica Clarke <jrtc27@jrtc27.com>                                         */
/*      Victor Moya <victor.moya@semidynamics.com>                                 */
/*                                                                                 */
/*  All rights reserved.                                                           */
/*                                                                                 */
/*  Redistribution and use in source and binary forms, with or without             */
/*  modification, are permitted provided that the following conditions             */
/*  are met:                                                                       */
/*  1. Redistributions of source code must retain the above copyright              */
/*     notice, this list of conditions and the following disclaimer.               */
/*  2. Redistributions in binary form must reproduce the above copyright           */
/*     notice, this list of conditions and the following disclaimer in             */
/*     the documentation and/or other materials provided with the                  */
/*     distribution.                                                               */
/*                                                                                 */
/*  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''             */
/*  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED              */
/*  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A                */
/*  PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR            */
/*  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,                   */
/*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT               */
/*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF               */
/*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND            */
/*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,             */
/*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT             */
/*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF             */
/*  SUCH DAMAGE.                                                                   */
/*=================================================================================*/

/* ******************************************************************************* */
/* This file implements part of the vector extension.                              */
/* Chapter 6: Configuration-Setting Instructions                                   */
/* ******************************************************************************* */

mapping sew_flag : string <-> bits(3) = {
  "e8"    <-> 0b000,
  "e16"   <-> 0b001,
  "e32"   <-> 0b010,
  "e64"   <-> 0b011
}

mapping maybe_lmul_flag : string <-> bits(3) = {
  ""              <-> 0b000, /* m1 by default */
  sep() ^ "mf8"   <-> 0b101,
  sep() ^ "mf4"   <-> 0b110,
  sep() ^ "mf2"   <-> 0b111,
  sep() ^ "m1"    <-> 0b000,
  sep() ^ "m2"    <-> 0b001,
  sep() ^ "m4"    <-> 0b010,
  sep() ^ "m8"    <-> 0b011
}

mapping maybe_ta_flag : string <-> bits(1) = {
  ""           <-> 0b0, /* tu by default */
  sep() ^ "ta" <-> 0b1,
  sep() ^ "tu" <-> 0b0
}

mapping maybe_ma_flag : string <-> bits(1) = {
  ""           <-> 0b0, /* mu by default */
  sep() ^ "ma" <-> 0b1,
  sep() ^ "mu" <-> 0b0
}

/* ****************************** vsetvli & vsetvl ******************************* */
union clause ast = VSET_TYPE : (vsetop, bits(1), bits(1), bits(3), bits(3), regidx, regidx)

mapping encdec_vsetop : vsetop <-> bits(4) ={
  VSETVLI <-> 0b0000,
  VSETVL  <-> 0b1000
}

mapping clause encdec = VSET_TYPE(op, ma, ta, sew, lmul, rs1, rd) if haveVExt()
  <-> encdec_vsetop(op) @ ma @ ta @ sew @ lmul @ rs1 @ 0b111 @ rd @ 0b1010111 if haveVExt()

function clause execute VSET_TYPE(op, ma, ta, sew, lmul, rs1, rd) = {
  let VLEN_pow      = get_vlen_pow();
  let ELEN_pow      = get_elen_pow();
  let LMUL_pow_ori  = get_lmul_pow();
  let SEW_pow_ori   = get_sew_pow();
  let ratio_pow_ori = SEW_pow_ori - LMUL_pow_ori;

  /* set vtype */
  match op {
    VSETVLI => {
      vtype->bits() = 0b0 @ zeros(sizeof(xlen) - 9) @ ma @ ta @ sew @ lmul
    },
    VSETVL  => {
      let rs2 : regidx = sew[1 .. 0] @ lmul;
      vtype->bits() = X(rs2)
    }
  };

  /* check legal SEW and LMUL and calculate VLMAX */
  let LMUL_pow_new = get_lmul_pow();
  let SEW_pow_new  = get_sew_pow();
  if SEW_pow_new > LMUL_pow_new + ELEN_pow then {
    /* Note: Implementations can set vill or trap if the vtype setting is not supported.
     * TODO: configuration support for both solutions
     */
    vtype->bits() = 0b1 @ zeros(sizeof(xlen) - 1); /* set vtype.vill */
    vl = zeros();
    print_reg("CSR vtype <- " ^ BitStr(vtype.bits()));
    print_reg("CSR vl <- " ^ BitStr(vl));
    return RETIRE_SUCCESS
  };
  let VLMAX = int_power(2, VLEN_pow + LMUL_pow_new - SEW_pow_new);

  /* set vl according to VLMAX and AVL */
  if (rs1 != 0b00000) then { /* normal stripmining */
    let rs1_val = X(rs1);
    let AVL = unsigned(rs1_val);
    vl = if AVL <= VLMAX then to_bits(sizeof(xlen), AVL)
         else if AVL < 2 * VLMAX then to_bits(sizeof(xlen), (AVL + 1) / 2)
         else to_bits(sizeof(xlen), VLMAX);
    /* Note: ceil(AVL / 2) ≤ vl ≤ VLMAX when VLMAX < AVL < (2 * VLMAX)
     * TODO: configuration support for either using ceil(AVL / 2) or VLMAX
     */
    X(rd) = vl;
  } else if (rd != 0b00000) then { /* set vl to VLMAX */
    let AVL = unsigned(ones(sizeof(xlen)));
    vl = to_bits(sizeof(xlen), VLMAX);
    X(rd) = vl;
  } else { /* keep existing vl */
    let AVL = unsigned(vl);
    let ratio_pow_new = SEW_pow_new - LMUL_pow_new;
    if (ratio_pow_new != ratio_pow_ori) then {
      /* Note: Implementations can set vill or trap if the vtype setting is not supported.
       * TODO: configuration support for both solutions
       */
      vtype->bits() = 0b1 @ zeros(sizeof(xlen) - 1); /* set vtype.vill */
      vl = zeros();
    }
  };
  print_reg("CSR vtype <- " ^ BitStr(vtype.bits()));
  print_reg("CSR vl <- " ^ BitStr(vl));

  /* reset vstart to 0 */
  vstart = zeros();
  print_reg("CSR vstart <- " ^ BitStr(vstart));

  RETIRE_SUCCESS
}

mapping vsettype_mnemonic : vsetop <-> string ={
  VSETVLI <-> "vsetvli",
  VSETVL  <-> "vsetvli"
}

mapping clause assembly = VSET_TYPE(op, ma, ta, sew, lmul, rs1, rd)
  <-> vsettype_mnemonic(op) ^ spc() ^ reg_name(rd) ^ sep() ^ reg_name(rs1) ^ sep() ^ sew_flag(sew) ^ maybe_lmul_flag(lmul) ^ maybe_ta_flag(ta) ^ maybe_ma_flag(ma)

/* ********************************* vsetivli ************************************ */
union clause ast = VSETI_TYPE : ( bits(1), bits(1), bits(3), bits(3), regidx, regidx)

mapping clause encdec = VSETI_TYPE(ma, ta, sew, lmul, uimm, rd) if haveVExt()
  <-> 0b1100 @ ma @ ta @ sew @ lmul @ uimm @ 0b111 @ rd @ 0b1010111 if haveVExt()

function clause execute VSETI_TYPE(ma, ta, sew, lmul, uimm, rd) = {
  let VLEN_pow      = get_vlen_pow();
  let ELEN_pow      = get_elen_pow();
  let LMUL_pow_ori  = get_lmul_pow();
  let SEW_pow_ori   = get_sew_pow();
  let ratio_pow_ori = SEW_pow_ori - LMUL_pow_ori;

  /* set vtype */
  vtype->bits() = 0b0 @ zeros(sizeof(xlen) - 9) @ ma @ ta @ sew @ lmul;

  /* check legal SEW and LMUL and calculate VLMAX */
  let LMUL_pow_new = get_lmul_pow();
  let SEW_pow_new  = get_sew_pow();
  if SEW_pow_new > LMUL_pow_new + ELEN_pow then {
    /* Note: Implementations can set vill or trap if the vtype setting is not supported.
     * TODO: configuration support for both solutions
     */
    vtype->bits() = 0b1 @ zeros(sizeof(xlen) - 1); /* set vtype.vill */
    vl = zeros();
    print_reg("CSR vtype <- " ^ BitStr(vtype.bits()));
    print_reg("CSR vl <- " ^ BitStr(vl));
    return RETIRE_SUCCESS
  };
  let VLMAX = int_power(2, VLEN_pow + LMUL_pow_new - SEW_pow_new);
  let AVL   = unsigned(uimm); /* AVL is encoded as 5-bit zero-extended imm in the rs1 field */

  /* set vl according to VLMAX and AVL */
  vl = if AVL <= VLMAX then to_bits(sizeof(xlen), AVL)
       else if AVL < 2 * VLMAX then to_bits(sizeof(xlen), (AVL + 1) / 2)
       else to_bits(sizeof(xlen), VLMAX);
  /* Note: ceil(AVL / 2) ≤ vl ≤ VLMAX when VLMAX < AVL < (2 * VLMAX)
   * TODO: configuration support for either using ceil(AVL / 2) or VLMAX
   */
  X(rd) = vl;
  print_reg("CSR vtype <- " ^ BitStr(vtype.bits()));
  print_reg("CSR vl <- " ^ BitStr(vl));

  /* reset vstart to 0 */
  vstart = zeros();
  print_reg("CSR vstart <- " ^ BitStr(vstart));

  RETIRE_SUCCESS
}

mapping clause assembly = VSETI_TYPE(ma, ta, sew, lmul, uimm, rd)
  <-> "vsetivli" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_5(uimm) ^ sep() ^ sew_flag(sew) ^ maybe_lmul_flag(lmul) ^ maybe_ta_flag(ta) ^ maybe_ma_flag(ma)