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Effectness analysis
author Adam Chlipala <adamc@hcoop.net>
date Thu, 16 Apr 2009 15:29:39 -0400
parents 2d64457eedb1
children dc3fc3f3b834
rev   line source
adamc@315 1 (* Copyright (c) 2008, Adam Chlipala
adamc@315 2 * All rights reserved.
adamc@315 3 *
adamc@315 4 * Redistribution and use in source and binary forms, with or without
adamc@315 5 * modification, are permitted provided that the following conditions are met:
adamc@315 6 *
adamc@315 7 * - Redistributions of source code must retain the above copyright notice,
adamc@315 8 * this list of conditions and the following disclaimer.
adamc@315 9 * - Redistributions in binary form must reproduce the above copyright notice,
adamc@315 10 * this list of conditions and the following disclaimer in the documentation
adamc@315 11 * and/or other materials provided with the distribution.
adamc@315 12 * - The names of contributors may not be used to endorse or promote products
adamc@315 13 * derived from this software without specific prior written permission.
adamc@315 14 *
adamc@315 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@315 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@315 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@315 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@315 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
adamc@315 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@315 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@315 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@315 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@315 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@315 25 * POSSIBILITY OF SUCH DAMAGE.
adamc@315 26 *)
adamc@315 27
adamc@315 28 (* Simplify a Core program by repeating polymorphic function definitions *)
adamc@315 29
adamc@315 30 structure Unpoly :> UNPOLY = struct
adamc@315 31
adamc@315 32 open Core
adamc@315 33
adamc@315 34 structure E = CoreEnv
adamc@315 35 structure U = CoreUtil
adamc@315 36
adamc@315 37 structure IS = IntBinarySet
adamc@315 38 structure IM = IntBinaryMap
adamc@315 39
adamc@315 40
adamc@315 41 (** The actual specialization *)
adamc@315 42
adamc@315 43 val liftConInCon = E.liftConInCon
adamc@315 44 val subConInCon = E.subConInCon
adamc@315 45
adamc@315 46 val liftConInExp = E.liftConInExp
adamc@315 47 val subConInExp = E.subConInExp
adamc@315 48
adamc@399 49 val isOpen = U.Con.exists {kind = fn _ => false,
adamc@399 50 con = fn c =>
adamc@399 51 case c of
adamc@399 52 CRel _ => true
adamc@399 53 | _ => false}
adamc@399 54
adamc@316 55 fun unpolyNamed (xn, rep) =
adamc@316 56 U.Exp.map {kind = fn k => k,
adamc@316 57 con = fn c => c,
adamc@316 58 exp = fn e =>
adamc@316 59 case e of
adamc@399 60 ECApp (e', _) =>
adamc@325 61 let
adamc@325 62 fun isTheOne (e, _) =
adamc@325 63 case e of
adamc@325 64 ENamed xn' => xn' = xn
adamc@325 65 | ECApp (e, _) => isTheOne e
adamc@325 66 | _ => false
adamc@325 67 in
adamc@325 68 if isTheOne e' then
adamc@399 69 rep
adamc@325 70 else
adamc@325 71 e
adamc@325 72 end
adamc@316 73 | _ => e}
adamc@316 74
adamc@315 75 type state = {
adamc@315 76 funcs : (kind list * (string * int * con * exp * string) list) IM.map,
adamc@315 77 decls : decl list,
adamc@315 78 nextName : int
adamc@315 79 }
adamc@315 80
adamc@315 81 fun kind (k, st) = (k, st)
adamc@315 82
adamc@315 83 fun con (c, st) = (c, st)
adamc@315 84
adamc@315 85 fun exp (e, st : state) =
adamc@315 86 case e of
adamc@315 87 ECApp _ =>
adamc@315 88 let
adamc@315 89 (*val () = Print.prefaces "exp" [("e", CorePrint.p_exp CoreEnv.empty (e, ErrorMsg.dummySpan))]*)
adamc@315 90
adamc@315 91 fun unravel (e, cargs) =
adamc@315 92 case e of
adamc@315 93 ECApp ((e, _), c) => unravel (e, c :: cargs)
adamc@315 94 | ENamed n => SOME (n, rev cargs)
adamc@315 95 | _ => NONE
adamc@315 96 in
adamc@315 97 case unravel (e, []) of
adamc@315 98 NONE => (e, st)
adamc@315 99 | SOME (n, cargs) =>
adamc@399 100 if List.exists isOpen cargs then
adamc@399 101 (e, st)
adamc@399 102 else
adamc@399 103 case IM.find (#funcs st, n) of
adamc@399 104 NONE => (e, st)
adamc@399 105 | SOME (ks, vis) =>
adamc@399 106 let
adamc@399 107 val (vis, nextName) = ListUtil.foldlMap
adamc@399 108 (fn ((x, n, t, e, s), nextName) =>
adamc@399 109 ((x, nextName, n, t, e, s), nextName + 1))
adamc@399 110 (#nextName st) vis
adamc@315 111
adamc@399 112 fun specialize (x, n, n_old, t, e, s) =
adamc@399 113 let
adamc@399 114 fun trim (t, e, cargs) =
adamc@399 115 case (t, e, cargs) of
adamc@399 116 ((TCFun (_, _, t), _),
adamc@399 117 (ECAbs (_, _, e), _),
adamc@399 118 carg :: cargs) =>
adamc@399 119 let
adamc@399 120 val t = subConInCon (length cargs, carg) t
adamc@399 121 val e = subConInExp (length cargs, carg) e
adamc@399 122 in
adamc@399 123 trim (t, e, cargs)
adamc@399 124 end
adamc@399 125 | (_, _, []) =>
adamc@399 126 let
adamc@399 127 val e = foldl (fn ((_, n, n_old, _, _, _), e) =>
adamc@399 128 unpolyNamed (n_old, ENamed n) e)
adamc@399 129 e vis
adamc@399 130 in
adamc@399 131 SOME (t, e)
adamc@399 132 end
adamc@399 133 | _ => NONE
adamc@399 134 in
adamc@399 135 (*Print.prefaces "specialize"
adamc@399 136 [("t", CorePrint.p_con CoreEnv.empty t),
adamc@399 137 ("e", CorePrint.p_exp CoreEnv.empty e),
adamc@399 138 ("|cargs|", Print.PD.string (Int.toString (length cargs)))];*)
adamc@399 139 Option.map (fn (t, e) => (x, n, n_old, t, e, s))
adamc@399 140 (trim (t, e, cargs))
adamc@399 141 end
adamc@315 142
adamc@399 143 val vis = List.map specialize vis
adamc@399 144 in
adamc@399 145 if List.exists (not o Option.isSome) vis orelse length cargs > length ks then
adamc@399 146 (e, st)
adamc@399 147 else
adamc@399 148 let
adamc@399 149 val vis = List.mapPartial (fn x => x) vis
adamc@399 150 val vis = map (fn (x, n, n_old, t, e, s) =>
adamc@399 151 (x ^ "_unpoly", n, n_old, t, e, s)) vis
adamc@399 152 val vis' = map (fn (x, n, _, t, e, s) =>
adamc@399 153 (x, n, t, e, s)) vis
adamc@316 154
adamc@399 155 val ks' = List.drop (ks, length cargs)
adamc@399 156 in
adamc@399 157 case List.find (fn (_, _, n_old, _, _, _) => n_old = n) vis of
adamc@399 158 NONE => raise Fail "Unpoly: Inconsistent 'val rec' record"
adamc@399 159 | SOME (_, n, _, _, _, _) =>
adamc@399 160 (ENamed n,
adamc@399 161 {funcs = foldl (fn (vi, funcs) =>
adamc@399 162 IM.insert (funcs, #2 vi, (ks', vis')))
adamc@399 163 (#funcs st) vis',
adamc@399 164 decls = (DValRec vis', ErrorMsg.dummySpan) :: #decls st,
adamc@399 165 nextName = nextName})
adamc@399 166 end
adamc@399 167 end
adamc@315 168 end
adamc@315 169 | _ => (e, st)
adamc@315 170
adamc@315 171 fun decl (d, st : state) =
adamc@315 172 case d of
adamc@315 173 DValRec (vis as ((x, n, t, e, s) :: rest)) =>
adamc@315 174 let
adamc@315 175 fun unravel (e, cargs) =
adamc@315 176 case e of
adamc@315 177 (ECAbs (_, k, e), _) =>
adamc@315 178 unravel (e, k :: cargs)
adamc@315 179 | _ => rev cargs
adamc@315 180
adamc@315 181 val cargs = unravel (e, [])
adamc@315 182
adamc@315 183 fun unravel (e, cargs) =
adamc@315 184 case (e, cargs) of
adamc@315 185 ((ECAbs (_, k, e), _), k' :: cargs) =>
adamc@315 186 U.Kind.compare (k, k') = EQUAL
adamc@315 187 andalso unravel (e, cargs)
adamc@315 188 | (_, []) => true
adamc@315 189 | _ => false
adamc@315 190 in
adamc@315 191 if List.exists (fn vi => not (unravel (#4 vi, cargs))) rest then
adamc@315 192 (d, st)
adamc@315 193 else
adamc@315 194 let
adamc@315 195 val ns = IS.addList (IS.empty, map #2 vis)
adamc@315 196 val nargs = length cargs
adamc@315 197
adamc@315 198 fun deAbs (e, cargs) =
adamc@315 199 case (e, cargs) of
adamc@315 200 ((ECAbs (_, _, e), _), _ :: cargs) => deAbs (e, cargs)
adamc@315 201 | (_, []) => e
adamc@315 202 | _ => raise Fail "Unpoly: deAbs"
adamc@315 203
adamc@315 204 (** Verifying lack of polymorphic recursion *)
adamc@315 205
adamc@315 206 fun kind _ = false
adamc@315 207 fun con _ = false
adamc@315 208
adamc@315 209 fun exp e =
adamc@315 210 case e of
adamc@315 211 ECApp (e, c) =>
adamc@315 212 let
adamc@315 213 fun isIrregular (e, pos) =
adamc@315 214 case #1 e of
adamc@315 215 ENamed n =>
adamc@315 216 IS.member (ns, n)
adamc@315 217 andalso
adamc@315 218 (case #1 c of
adamc@315 219 CRel i => i <> nargs - pos
adamc@315 220 | _ => true)
adamc@315 221 | ECApp (e, _) => isIrregular (e, pos + 1)
adamc@315 222 | _ => false
adamc@315 223 in
adamc@315 224 isIrregular (e, 1)
adamc@315 225 end
adamc@315 226 | ECAbs _ => true
adamc@315 227 | _ => false
adamc@315 228
adamc@315 229 val irregular = U.Exp.exists {kind = kind, con = con, exp = exp}
adamc@315 230 in
adamc@315 231 if List.exists (fn x => irregular (deAbs (#4 x, cargs))) vis then
adamc@315 232 (d, st)
adamc@315 233 else
adamc@315 234 (d, {funcs = foldl (fn (vi, funcs) =>
adamc@315 235 IM.insert (funcs, #2 vi, (cargs, vis)))
adamc@315 236 (#funcs st) vis,
adamc@315 237 decls = #decls st,
adamc@315 238 nextName = #nextName st})
adamc@315 239 end
adamc@315 240 end
adamc@315 241
adamc@315 242 | _ => (d, st)
adamc@315 243
adamc@315 244 val polyDecl = U.Decl.foldMap {kind = kind, con = con, exp = exp, decl = decl}
adamc@315 245
adamc@315 246 fun unpoly file =
adamc@315 247 let
adamc@315 248 fun doDecl (d : decl, st : state) =
adamc@315 249 let
adamc@315 250 val (d, st) = polyDecl st d
adamc@315 251 in
adamc@315 252 (rev (d :: #decls st),
adamc@315 253 {funcs = #funcs st,
adamc@315 254 decls = [],
adamc@315 255 nextName = #nextName st})
adamc@315 256 end
adamc@315 257
adamc@315 258 val (ds, _) = ListUtil.foldlMapConcat doDecl
adamc@315 259 {funcs = IM.empty,
adamc@315 260 decls = [],
adamc@315 261 nextName = U.File.maxName file + 1} file
adamc@315 262 in
adamc@315 263 ds
adamc@315 264 end
adamc@315 265
adamc@315 266 end