hvm 1.0.17-beta

A massively parallel functional runtime.
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

use crate::runtime::{*};

#[inline(always)]
pub fn visit(ctx: ReduceCtx) -> bool {
  let goup = ctx.redex.insert(ctx.tid, new_redex(*ctx.host, *ctx.cont, 1));
  *ctx.cont = goup;
  *ctx.host = get_loc(ctx.term, 2);
  return true;
}

#[inline(always)]
pub fn apply(ctx: ReduceCtx) -> bool {

  let arg0 = load_arg(ctx.heap, ctx.term, 2);
  let tcol = get_ext(ctx.term);

  // dup r s = λx(f)
  // --------------- DUP-LAM
  // dup f0 f1 = f
  // r <- λx0(f0)
  // s <- λx1(f1)
  // x <- {x0 x1}
  if get_tag(arg0) == LAM {
    inc_cost(ctx.heap, ctx.tid);
    let let0 = alloc(ctx.heap, ctx.tid, 3);
    let par0 = alloc(ctx.heap, ctx.tid, 2);
    let lam0 = alloc(ctx.heap, ctx.tid, 2);
    let lam1 = alloc(ctx.heap, ctx.tid, 2);
    link(ctx.heap, let0 + 2, take_arg(ctx.heap, arg0, 1));
    link(ctx.heap, par0 + 1, Var(lam1));
    link(ctx.heap, par0 + 0, Var(lam0));
    link(ctx.heap, lam0 + 1, Dp0(get_ext(ctx.term), let0));
    link(ctx.heap, lam1 + 1, Dp1(get_ext(ctx.term), let0));
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Var(get_loc(arg0, 0)), Sup(get_ext(ctx.term), par0));
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp0(tcol, get_loc(ctx.term, 0)), Lam(lam0));
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp1(tcol, get_loc(ctx.term, 0)), Lam(lam1));
    let done = Lam(if get_tag(ctx.term) == DP0 { lam0 } else { lam1 });
    link(ctx.heap, *ctx.host, done);
    free(ctx.heap, ctx.tid, get_loc(ctx.term, 0), 3);
    free(ctx.heap, ctx.tid, get_loc(arg0, 0), 2);
    return true;
  }

  // dup x y = {a b}              
  // --------------- DUP-SUP
  // if equal: | else:        
  // x <- a    | x <- {xA xB} 
  // y <- b    | y <- {yA yB} 
  //           | dup xA yA = a
  //           | dup xB yB = b
  else if get_tag(arg0) == SUP {

    if tcol == get_ext(arg0) {
      inc_cost(ctx.heap, ctx.tid);
      atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp0(tcol, get_loc(ctx.term, 0)), take_arg(ctx.heap, arg0, 0));
      atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp1(tcol, get_loc(ctx.term, 0)), take_arg(ctx.heap, arg0, 1));
      free(ctx.heap, ctx.tid, get_loc(ctx.term, 0), 3);
      free(ctx.heap, ctx.tid, get_loc(arg0, 0), 2);
      return true;

    } else {
      inc_cost(ctx.heap, ctx.tid);
      let par0 = alloc(ctx.heap, ctx.tid, 2);
      let let0 = alloc(ctx.heap, ctx.tid, 3);
      let par1 = get_loc(arg0, 0);
      let let1 = alloc(ctx.heap, ctx.tid, 3);
      link(ctx.heap, let0 + 2, take_arg(ctx.heap, arg0, 0));
      link(ctx.heap, let1 + 2, take_arg(ctx.heap, arg0, 1));
      link(ctx.heap, par1 + 0, Dp1(tcol, let0));
      link(ctx.heap, par1 + 1, Dp1(tcol, let1));
      link(ctx.heap, par0 + 0, Dp0(tcol, let0));
      link(ctx.heap, par0 + 1, Dp0(tcol, let1));
      atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp0(tcol, get_loc(ctx.term, 0)), Sup(get_ext(arg0), par0));
      atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp1(tcol, get_loc(ctx.term, 0)), Sup(get_ext(arg0), par1));
      free(ctx.heap, ctx.tid, get_loc(ctx.term, 0), 3);
      return true;
    }
  }

  // dup x y = N
  // ----------- DUP-U60
  // x <- N
  // y <- N
  // ~
  else if get_tag(arg0) == U60 {
    inc_cost(ctx.heap, ctx.tid);
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp0(tcol, get_loc(ctx.term, 0)), arg0);
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp1(tcol, get_loc(ctx.term, 0)), arg0);
    free(ctx.heap, ctx.tid, get_loc(ctx.term, 0), 3);
    return true;
  }

  // dup x y = N
  // ----------- DUP-F60
  // x <- N
  // y <- N
  // ~
  else if get_tag(arg0) == F60 {
    inc_cost(ctx.heap, ctx.tid);
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp0(tcol, get_loc(ctx.term, 0)), arg0);
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp1(tcol, get_loc(ctx.term, 0)), arg0);
    free(ctx.heap, ctx.tid, get_loc(ctx.term, 0), 3);
    return true;
  }

  // dup x y = (K a b c ...)
  // ----------------------- DUP-CTR
  // dup a0 a1 = a
  // dup b0 b1 = b
  // dup c0 c1 = c
  // ...
  // x <- (K a0 b0 c0 ...)
  // y <- (K a1 b1 c1 ...)
  else if get_tag(arg0) == CTR {
    inc_cost(ctx.heap, ctx.tid);
    let fnum = get_ext(arg0);
    let fari = arity_of(&ctx.prog.aris, arg0);
    if fari == 0 {
      atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp0(tcol, get_loc(ctx.term, 0)), Ctr(fnum, 0));
      atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp1(tcol, get_loc(ctx.term, 0)), Ctr(fnum, 0));
      link(ctx.heap, *ctx.host, Ctr(fnum, 0));
      free(ctx.heap, ctx.tid, get_loc(ctx.term, 0), 3);
    } else {
      let ctr0 = get_loc(arg0, 0);
      let ctr1 = alloc(ctx.heap, ctx.tid, fari);
      for i in 0 .. fari - 1 {
        let leti = alloc(ctx.heap, ctx.tid, 3);
        link(ctx.heap, leti + 2, take_arg(ctx.heap, arg0, i));
        link(ctx.heap, ctr0 + i, Dp0(get_ext(ctx.term), leti));
        link(ctx.heap, ctr1 + i, Dp1(get_ext(ctx.term), leti));
      }
      let leti = alloc(ctx.heap, ctx.tid, 3);
      link(ctx.heap, leti + 2, take_arg(ctx.heap, arg0, fari - 1));
      link(ctx.heap, ctr0 + fari - 1, Dp0(get_ext(ctx.term), leti));
      link(ctx.heap, ctr1 + fari - 1, Dp1(get_ext(ctx.term), leti));
      atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp0(tcol, get_loc(ctx.term, 0)), Ctr(fnum, ctr0));
      atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp1(tcol, get_loc(ctx.term, 0)), Ctr(fnum, ctr1));
      free(ctx.heap, ctx.tid, get_loc(ctx.term, 0), 3);
    }
    return true;
  }

  // dup x y = *
  // ----------- DUP-ERA
  // x <- *
  // y <- *
  else if get_tag(arg0) == ERA {
    inc_cost(ctx.heap, ctx.tid);
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp0(tcol, get_loc(ctx.term, 0)), Era());
    atomic_subst(ctx.heap, &ctx.prog.aris, ctx.tid, Dp1(tcol, get_loc(ctx.term, 0)), Era());
    link(ctx.heap, *ctx.host, Era());
    free(ctx.heap, ctx.tid, get_loc(ctx.term, 0), 3);
    return true;
  }

  else {
    return false;
  }
}