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Abstract type for evalExp state; handle WHERE conditions soundly
author Adam Chlipala <adamc@hcoop.net>
date Sat, 10 Apr 2010 10:24:13 -0400
parents 648e6b087dfb
children 950d1e540df6
rev   line source
adamc@133 1 (* Copyright (c) 2008, Adam Chlipala
adamc@133 2 * All rights reserved.
adamc@133 3 *
adamc@133 4 * Redistribution and use in source and binary forms, with or without
adamc@133 5 * modification, are permitted provided that the following conditions are met:
adamc@133 6 *
adamc@133 7 * - Redistributions of source code must retain the above copyright notice,
adamc@133 8 * this list of conditions and the following disclaimer.
adamc@133 9 * - Redistributions in binary form must reproduce the above copyright notice,
adamc@133 10 * this list of conditions and the following disclaimer in the documentation
adamc@133 11 * and/or other materials provided with the distribution.
adamc@133 12 * - The names of contributors may not be used to endorse or promote products
adamc@133 13 * derived from this software without specific prior written permission.
adamc@133 14 *
adamc@133 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@133 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@133 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@133 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@133 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
adamc@133 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@133 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@133 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@133 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@133 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@133 25 * POSSIBILITY OF SUCH DAMAGE.
adamc@133 26 *)
adamc@133 27
adamc@133 28 (* Simplify a Mono program algebraically *)
adamc@133 29
adamc@133 30 structure MonoReduce :> MONO_REDUCE = struct
adamc@133 31
adamc@133 32 open Mono
adamc@133 33
adamc@133 34 structure E = MonoEnv
adamc@133 35 structure U = MonoUtil
adamc@133 36
adamc@470 37 structure IM = IntBinaryMap
adamc@916 38 structure IS = IntBinarySet
adamc@470 39
adamc@133 40
adamc@948 41 fun simpleTypeImpure tsyms =
adamc@919 42 U.Typ.exists (fn TFun _ => true
adamc@948 43 | TDatatype (n, _) => IS.member (tsyms, n)
adamc@919 44 | _ => false)
adamc@919 45
adamc@948 46 fun simpleImpure (tsyms, syms) =
adamc@919 47 U.Exp.existsB {typ = fn _ => false,
adamc@919 48 exp = fn (env, e) =>
adamc@919 49 case e of
adamc@919 50 EWrite _ => true
adamc@919 51 | EQuery _ => true
adamc@919 52 | EDml _ => true
adamc@919 53 | ENextval _ => true
adamc@1073 54 | ESetval _ => true
adamc@1171 55 | EFfiApp (m, x, _) => Settings.isEffectful (m, x) orelse Settings.isBenignEffectful (m, x)
adamc@919 56 | EServerCall _ => true
adamc@919 57 | ERecv _ => true
adamc@919 58 | ESleep _ => true
adamc@919 59 | ENamed n => IS.member (syms, n)
adamc@1069 60 | EError _ => true
adamc@919 61 | ERel n =>
adamc@919 62 let
adamc@919 63 val (_, t, _) = E.lookupERel env n
adamc@919 64 in
adamc@948 65 simpleTypeImpure tsyms t
adamc@919 66 end
adamc@919 67 | _ => false,
adamc@919 68 bind = fn (env, b) =>
adamc@919 69 case b of
adamc@919 70 U.Exp.RelE (x, t) => E.pushERel env x t NONE
adamc@919 71 | _ => env}
adamc@916 72
adamc@252 73 fun impure (e, _) =
adamc@252 74 case e of
adamc@252 75 EWrite _ => true
adamc@252 76 | EQuery _ => true
adamc@307 77 | EDml _ => true
adamc@338 78 | ENextval _ => true
adamc@1073 79 | ESetval _ => true
adamc@463 80 | EUnurlify _ => true
adamc@252 81 | EAbs _ => false
adamc@252 82
adamc@252 83 | EPrim _ => false
adamc@252 84 | ERel _ => false
adamc@252 85 | ENamed _ => false
adamc@252 86 | ECon (_, _, eo) => (case eo of NONE => false | SOME e => impure e)
adamc@297 87 | ENone _ => false
adamc@290 88 | ESome (_, e) => impure e
adamc@252 89 | EFfi _ => false
adamc@1171 90 | EFfiApp (m, x, _) => Settings.isEffectful (m, x) orelse Settings.isBenignEffectful (m, x)
adamc@252 91 | EApp ((EFfi _, _), _) => false
adamc@252 92 | EApp _ => true
adamc@252 93
adamc@387 94 | EUnop (_, e) => impure e
adamc@387 95 | EBinop (_, e1, e2) => impure e1 orelse impure e2
adamc@387 96
adamc@252 97 | ERecord xes => List.exists (fn (_, e, _) => impure e) xes
adamc@252 98 | EField (e, _) => impure e
adamc@252 99
adamc@252 100 | ECase (e, pes, _) => impure e orelse List.exists (fn (_, e) => impure e) pes
adamc@252 101
adamc@1069 102 | EError _ => true
adamc@741 103 | EReturnBlob {blob = e1, mimeType = e2, ...} => impure e1 orelse impure e2
adamc@1065 104 | ERedirect (e, _) => impure e
adamc@283 105
adamc@252 106 | EStrcat (e1, e2) => impure e1 orelse impure e2
adamc@252 107
adamc@252 108 | ESeq (e1, e2) => impure e1 orelse impure e2
adamc@252 109 | ELet (_, _, e1, e2) => impure e1 orelse impure e2
adamc@252 110
adamc@252 111 | EClosure (_, es) => List.exists impure es
adamc@815 112 | EJavaScript (_, e) => impure e
adamc@568 113 | ESignalReturn e => impure e
adamc@572 114 | ESignalBind (e1, e2) => impure e1 orelse impure e2
adamc@574 115 | ESignalSource e => impure e
adamc@608 116 | EServerCall _ => true
adamc@670 117 | ERecv _ => true
adamc@695 118 | ESleep _ => true
adamc@1021 119 | ESpawn _ => true
adamc@252 120
adamc@252 121 val liftExpInExp = Monoize.liftExpInExp
adamc@252 122
adamc@829 123 fun multiLift n e =
adamc@829 124 case n of
adamc@829 125 0 => e
adamc@829 126 | _ => multiLift (n - 1) (liftExpInExp 0 e)
adamc@829 127
adamc@252 128 val subExpInExp' =
adamc@133 129 U.Exp.mapB {typ = fn t => t,
adamc@133 130 exp = fn (xn, rep) => fn e =>
adamc@133 131 case e of
adamc@133 132 ERel xn' =>
adamc@133 133 (case Int.compare (xn', xn) of
adamc@133 134 EQUAL => #1 rep
adamc@133 135 | GREATER=> ERel (xn' - 1)
adamc@133 136 | LESS => e)
adamc@133 137 | _ => e,
adamc@133 138 bind = fn ((xn, rep), U.Exp.RelE _) => (xn+1, liftExpInExp 0 rep)
adamc@133 139 | (ctx, _) => ctx}
adamc@133 140
adamc@252 141 fun subExpInExp (n, e1) e2 =
adamc@252 142 let
adamc@252 143 val r = subExpInExp' (n, e1) e2
adamc@252 144 in
adamc@252 145 (*Print.prefaces "subExpInExp" [("e1", MonoPrint.p_exp MonoEnv.empty e1),
adamc@252 146 ("e2", MonoPrint.p_exp MonoEnv.empty e2),
adamc@252 147 ("r", MonoPrint.p_exp MonoEnv.empty r)];*)
adamc@252 148 r
adamc@252 149 end
adamc@133 150
adamc@133 151 fun typ c = c
adamc@133 152
adamc@316 153 val swapExpVars =
adamc@316 154 U.Exp.mapB {typ = fn t => t,
adamc@316 155 exp = fn lower => fn e =>
adamc@316 156 case e of
adamc@316 157 ERel xn =>
adamc@316 158 if xn = lower then
adamc@316 159 ERel (lower + 1)
adamc@316 160 else if xn = lower + 1 then
adamc@316 161 ERel lower
adamc@316 162 else
adamc@316 163 e
adamc@316 164 | _ => e,
adamc@316 165 bind = fn (lower, U.Exp.RelE _) => lower+1
adamc@316 166 | (lower, _) => lower}
adamc@316 167
adamc@341 168 val swapExpVarsPat =
adamc@341 169 U.Exp.mapB {typ = fn t => t,
adamc@341 170 exp = fn (lower, len) => fn e =>
adamc@341 171 case e of
adamc@341 172 ERel xn =>
adamc@341 173 if xn = lower then
adamc@827 174 ERel (lower + len)
adamc@341 175 else if xn >= lower + 1 andalso xn < lower + 1 + len then
adamc@341 176 ERel (xn - 1)
adamc@341 177 else
adamc@341 178 e
adamc@341 179 | _ => e,
adamc@341 180 bind = fn ((lower, len), U.Exp.RelE _) => (lower+1, len)
adamc@341 181 | (st, _) => st}
adamc@341 182
adamc@814 183 datatype result = Yes of exp list | No | Maybe
adamc@258 184
adamc@183 185 fun match (env, p : pat, e : exp) =
adamc@183 186 case (#1 p, #1 e) of
adamc@258 187 (PWild, _) => Yes env
adamc@814 188 | (PVar (x, t), _) => Yes (e :: env)
adamc@183 189
adamc@280 190 | (PPrim (Prim.String s), EStrcat ((EPrim (Prim.String s'), _), _)) =>
adamc@280 191 if String.isPrefix s' s then
adamc@280 192 Maybe
adamc@280 193 else
adamc@280 194 No
adamc@280 195
adamc@1207 196 | (PPrim (Prim.String s), EStrcat (_, (EPrim (Prim.String s'), _))) =>
adamc@1207 197 if String.isSuffix s' s then
adamc@1207 198 Maybe
adamc@1207 199 else
adamc@1207 200 No
adamc@1207 201
adamc@183 202 | (PPrim p, EPrim p') =>
adamc@183 203 if Prim.equal (p, p') then
adamc@258 204 Yes env
adamc@183 205 else
adamc@258 206 No
adamc@183 207
adamc@188 208 | (PCon (_, PConVar n1, NONE), ECon (_, PConVar n2, NONE)) =>
adamc@183 209 if n1 = n2 then
adamc@258 210 Yes env
adamc@183 211 else
adamc@258 212 No
adamc@183 213
adamc@188 214 | (PCon (_, PConVar n1, SOME p), ECon (_, PConVar n2, SOME e)) =>
adamc@183 215 if n1 = n2 then
adamc@183 216 match (env, p, e)
adamc@183 217 else
adamc@258 218 No
adamc@183 219
adamc@188 220 | (PCon (_, PConFfi {mod = m1, con = con1, ...}, NONE), ECon (_, PConFfi {mod = m2, con = con2, ...}, NONE)) =>
adamc@185 221 if m1 = m2 andalso con1 = con2 then
adamc@258 222 Yes env
adamc@185 223 else
adamc@258 224 No
adamc@185 225
adamc@188 226 | (PCon (_, PConFfi {mod = m1, con = con1, ...}, SOME ep), ECon (_, PConFfi {mod = m2, con = con2, ...}, SOME e)) =>
adamc@185 227 if m1 = m2 andalso con1 = con2 then
adamc@185 228 match (env, p, e)
adamc@185 229 else
adamc@258 230 No
adamc@185 231
adamc@183 232 | (PRecord xps, ERecord xes) =>
adamc@183 233 let
adamc@183 234 fun consider (xps, env) =
adamc@183 235 case xps of
adamc@258 236 [] => Yes env
adamc@183 237 | (x, p, _) :: rest =>
adamc@183 238 case List.find (fn (x', _, _) => x' = x) xes of
adamc@258 239 NONE => No
adamc@183 240 | SOME (_, e, _) =>
adamc@183 241 case match (env, p, e) of
adamc@258 242 No => No
adamc@258 243 | Maybe => Maybe
adamc@258 244 | Yes env => consider (rest, env)
adamc@183 245 in
adamc@183 246 consider (xps, env)
adamc@183 247 end
adamc@183 248
adamc@726 249 | (PNone _, ENone _) => Yes env
adamc@921 250 | (PNone _, ESome _) => No
adamc@726 251 | (PSome (_, p), ESome (_, e)) => match (env, p, e)
adamc@921 252 | (PSome _, ENone _) => No
adamc@726 253
adamc@258 254 | _ => Maybe
adamc@183 255
adamc@318 256 datatype event =
adamc@318 257 WritePage
adamc@318 258 | ReadDb
adamc@318 259 | WriteDb
adamc@481 260 | UseRel
adamc@318 261 | Unsure
adamc@318 262
adamc@318 263 fun p_event e =
adamc@318 264 let
adamc@318 265 open Print.PD
adamc@318 266 in
adamc@318 267 case e of
adamc@318 268 WritePage => string "WritePage"
adamc@318 269 | ReadDb => string "ReadDb"
adamc@318 270 | WriteDb => string "WriteDb"
adamc@481 271 | UseRel => string "UseRel"
adamc@318 272 | Unsure => string "Unsure"
adamc@318 273 end
adamc@318 274
adamc@470 275 val p_events = Print.p_list p_event
adamc@470 276
adamc@318 277 fun patBinds (p, _) =
adamc@318 278 case p of
adamc@318 279 PWild => 0
adamc@318 280 | PVar _ => 1
adamc@318 281 | PPrim _ => 0
adamc@318 282 | PCon (_, _, NONE) => 0
adamc@318 283 | PCon (_, _, SOME p) => patBinds p
adamc@318 284 | PRecord xpts => foldl (fn ((_, p, _), n) => n + patBinds p) 0 xpts
adamc@318 285 | PNone _ => 0
adamc@318 286 | PSome (_, p) => patBinds p
adamc@318 287
adamc@932 288 val countFree = U.Exp.foldB {typ = fn (_, n) => n,
adamc@932 289 exp = fn (x, e, n) =>
adamc@932 290 case e of
adamc@932 291 ERel x' => if x = x' then n + 1 else n
adamc@932 292 | _ => n,
adamc@932 293 bind = fn (n, b) =>
adamc@932 294 case b of
adamc@932 295 U.Exp.RelE _ => n + 1
adamc@975 296 | _ => n}
adamc@975 297
adamc@975 298 val freeInAbs = U.Exp.existsB {typ = fn _ => false,
adamc@975 299 exp = fn (n, e) =>
adamc@975 300 case e of
adamc@975 301 EAbs (_, _, _, b) => countFree n 0 b > 0
adamc@975 302 | EJavaScript (_, b) => countFree n 0 b > 0
adamc@975 303 | _ => false,
adamc@975 304 bind = fn (n, b) =>
adamc@975 305 case b of
adamc@975 306 U.Exp.RelE _ => n + 1
adamc@975 307 | _ => n} 0
adamc@932 308
adamc@470 309 fun reduce file =
adamc@470 310 let
adamc@948 311 val (timpures, impures, absCounts) =
adamc@948 312 foldl (fn ((d, _), (timpures, impures, absCounts)) =>
adamc@916 313 let
adamc@916 314 fun countAbs (e, _) =
adamc@916 315 case e of
adamc@916 316 EAbs (_, _, _, e) => 1 + countAbs e
adamc@916 317 | _ => 0
adamc@916 318 in
adamc@916 319 case d of
adamc@948 320 DDatatype dts =>
adamc@948 321 (if List.exists (fn (_, _, cs) =>
adamc@948 322 List.exists (fn (_, _, NONE) => false
adamc@948 323 | (_, _, SOME t) => simpleTypeImpure timpures t) cs)
adamc@948 324 dts then
adamc@948 325 IS.addList (timpures, map #2 dts)
adamc@948 326 else
adamc@948 327 timpures,
adamc@948 328 impures,
adamc@948 329 absCounts)
adamc@948 330 | DVal (_, n, _, e, _) =>
adamc@948 331 (timpures,
adamc@948 332 if simpleImpure (timpures, impures) E.empty e then
adamc@916 333 IS.add (impures, n)
adamc@916 334 else
adamc@916 335 impures,
adamc@916 336 IM.insert (absCounts, n, countAbs e))
adamc@916 337 | DValRec vis =>
adamc@948 338 (timpures,
adamc@948 339 if List.exists (fn (_, _, _, e, _) => simpleImpure (timpures, impures) E.empty e) vis then
adamc@916 340 foldl (fn ((_, n, _, _, _), impures) =>
adamc@916 341 IS.add (impures, n)) impures vis
adamc@916 342 else
adamc@916 343 impures,
adamc@916 344 foldl (fn ((x, n, _, e, _), absCounts) =>
adamc@916 345 IM.insert (absCounts, n, countAbs e))
adamc@916 346 absCounts vis)
adamc@948 347 | _ => (timpures, impures, absCounts)
adamc@916 348 end)
adamc@948 349 (IS.empty, IS.empty, IM.empty) file
adamc@387 350
adamc@1017 351 val uses = U.File.fold {typ = fn (_, m) => m,
adamc@1017 352 exp = fn (e, m) =>
adamc@1017 353 case e of
adamc@1017 354 ENamed n => IM.insert (m, n, 1 + Option.getOpt (IM.find (m, n), 0))
adamc@1017 355 | _ => m,
adamc@1017 356 decl = fn (_, m) => m}
adamc@1017 357 IM.empty file
adamc@1017 358
adamc@1017 359 val size = U.Exp.fold {typ = fn (_, n) => n,
adamc@1017 360 exp = fn (_, n) => n + 1} 0
adamc@1017 361
adamc@1017 362 fun mayInline (n, e) =
adamc@1017 363 case IM.find (uses, n) of
adamc@1017 364 NONE => false
adamc@1017 365 | SOME count => count <= 1
adamc@1017 366 orelse size e <= Settings.getMonoInline ()
adamc@1017 367
adamc@470 368 fun summarize d (e, _) =
adamc@579 369 let
adamc@579 370 val s =
adamc@579 371 case e of
adamc@579 372 EPrim _ => []
adamc@579 373 | ERel n => if n = d then [UseRel] else []
adamc@579 374 | ENamed _ => []
adamc@579 375 | ECon (_, _, NONE) => []
adamc@579 376 | ECon (_, _, SOME e) => summarize d e
adamc@579 377 | ENone _ => []
adamc@579 378 | ESome (_, e) => summarize d e
adamc@579 379 | EFfi _ => []
adamc@765 380 | EFfiApp (m, x, es) =>
adamc@1171 381 if Settings.isEffectful (m, x) orelse Settings.isBenignEffectful (m, x) then
adamc@765 382 List.concat (map (summarize d) es) @ [Unsure]
adamc@765 383 else
adamc@765 384 List.concat (map (summarize d) es)
adamc@579 385 | EApp ((EFfi _, _), e) => summarize d e
adamc@579 386 | EApp _ =>
adamc@579 387 let
adamc@694 388 fun unravel (e, passed, ls) =
adamc@579 389 case e of
adamc@579 390 ENamed n =>
adamc@579 391 let
adamc@579 392 val ls = rev ls
adamc@579 393 in
adamc@948 394 if IS.member (impures, n) then
adamc@948 395 case IM.find (absCounts, n) of
adamc@948 396 NONE => [Unsure]
adamc@948 397 | SOME len =>
adamc@948 398 if passed < len then
adamc@948 399 ls
adamc@948 400 else
adamc@948 401 ls @ [Unsure]
adamc@948 402 else
adamc@948 403 ls
adamc@579 404 end
adamc@579 405 | ERel n => List.revAppend (ls,
adamc@579 406 if n = d then
adamc@579 407 [UseRel, Unsure]
adamc@579 408 else
adamc@579 409 [Unsure])
adamc@579 410 | EApp (f, x) =>
adamc@995 411 unravel (#1 f, passed + 1, List.revAppend (summarize d x,
adamc@995 412 ls))
adamc@579 413 | _ => [Unsure]
adamc@579 414 in
adamc@694 415 unravel (e, 0, [])
adamc@579 416 end
adamc@252 417
adamc@941 418 | EAbs _ => []
adamc@316 419
adamc@579 420 | EUnop (_, e) => summarize d e
adamc@579 421 | EBinop (_, e1, e2) => summarize d e1 @ summarize d e2
adamc@470 422
adamc@579 423 | ERecord xets => List.concat (map (summarize d o #2) xets)
adamc@579 424 | EField (e, _) => summarize d e
adamc@470 425
adamc@1214 426 | ECase (e, pes, _) =>
adamc@1214 427 let
adamc@579 428 val lss = map (fn (p, e) => summarize (d + patBinds p) e) pes
adamc@579 429 in
adamc@579 430 case lss of
adamc@579 431 [] => raise Fail "Empty pattern match"
adamc@579 432 | ls :: lss =>
adamc@1214 433 summarize d e
adamc@1214 434 @ (if List.all (fn ls' => ls' = ls) lss then
adamc@1214 435 ls
adamc@1214 436 else if length (List.filter (not o List.null) (ls :: lss)) <= 1 then
adamc@1214 437 valOf (List.find (not o List.null) (ls :: lss))
adamc@1214 438 else
adamc@1214 439 [Unsure])
adamc@1214 440 end
adamc@579 441 | EStrcat (e1, e2) => summarize d e1 @ summarize d e2
adamc@316 442
adamc@579 443 | EError (e, _) => summarize d e @ [Unsure]
adamc@741 444 | EReturnBlob {blob = e1, mimeType = e2, ...} => summarize d e1 @ summarize d e2 @ [Unsure]
adamc@1065 445 | ERedirect (e, _) => summarize d e @ [Unsure]
adamc@318 446
adamc@579 447 | EWrite e => summarize d e @ [WritePage]
adamc@579 448
adamc@579 449 | ESeq (e1, e2) => summarize d e1 @ summarize d e2
adamc@579 450 | ELet (_, _, e1, e2) => summarize d e1 @ summarize (d + 1) e2
adamc@456 451
adamc@579 452 | EClosure (_, es) => List.concat (map (summarize d) es)
adamc@470 453
adamc@579 454 | EQuery {query, body, initial, ...} =>
adamc@579 455 List.concat [summarize d query,
adamc@579 456 summarize d initial,
adamc@941 457 [ReadDb],
adamc@941 458 summarize (d + 2) body]
adamc@470 459
adamc@579 460 | EDml e => summarize d e @ [WriteDb]
adamc@579 461 | ENextval e => summarize d e @ [WriteDb]
adamc@1073 462 | ESetval (e1, e2) => summarize d e1 @ summarize d e2 @ [WriteDb]
adamc@1112 463 | EUnurlify (e, _, _) => summarize d e
adamc@815 464 | EJavaScript (_, e) => summarize d e
adamc@579 465 | ESignalReturn e => summarize d e
adamc@579 466 | ESignalBind (e1, e2) => summarize d e1 @ summarize d e2
adamc@579 467 | ESignalSource e => summarize d e
adamc@608 468
adamc@1020 469 | EServerCall (e, _, _) => summarize d e @ [Unsure]
adamc@1021 470 | ERecv (e, _) => summarize d e @ [Unsure]
adamc@1021 471 | ESleep e => summarize d e @ [Unsure]
adamc@1021 472 | ESpawn e => summarize d e @ [Unsure]
adamc@579 473 in
adamc@579 474 (*Print.prefaces "Summarize"
adamc@579 475 [("e", MonoPrint.p_exp MonoEnv.empty (e, ErrorMsg.dummySpan)),
adamc@579 476 ("d", Print.PD.string (Int.toString d)),
adamc@579 477 ("s", p_events s)];*)
adamc@579 478 s
adamc@579 479 end
adamc@470 480
adamc@919 481 val impure = fn env => fn e =>
adamc@948 482 simpleImpure (timpures, impures) env e andalso impure e
adamc@916 483 andalso not (List.null (summarize ~1 e))
adamc@916 484
adamc@470 485 fun exp env e =
adamc@470 486 let
adamc@470 487 (*val () = Print.prefaces "exp" [("e", MonoPrint.p_exp env (e, ErrorMsg.dummySpan))]*)
adamc@470 488
adamc@1017 489 fun doLet (x, t, e', b) =
adamc@1017 490 let
adamc@1017 491 fun doSub () =
adamc@1017 492 let
adamc@1017 493 val r = subExpInExp (0, e') b
adamc@1017 494 in
adamc@1017 495 (*Print.prefaces "doSub" [("e'", MonoPrint.p_exp env e'),
adamc@1017 496 ("b", MonoPrint.p_exp (E.pushERel env x t NONE) b),
adamc@1017 497 ("r", MonoPrint.p_exp env r)];*)
adamc@1017 498 #1 (reduceExp env r)
adamc@1017 499 end
adamc@1017 500
adamc@1017 501 fun trySub () =
adamc@1017 502 ((*Print.prefaces "trySub"
adamc@1017 503 [("e", MonoPrint.p_exp env (e, ErrorMsg.dummySpan))];*)
adamc@1017 504 case t of
adamc@1017 505 (TFfi ("Basis", "string"), _) => doSub ()
adamc@1017 506 | (TSignal _, _) => e
adamc@1017 507 | _ =>
adamc@1017 508 case e' of
adamc@1017 509 (ECase _, _) => e
adamc@1017 510 | _ => doSub ())
adamc@1017 511 in
adamc@1017 512 if impure env e' then
adamc@1017 513 let
adamc@1017 514 val effs_e' = summarize 0 e'
adamc@1017 515 val effs_e' = List.filter (fn x => x <> UseRel) effs_e'
adamc@1017 516 val effs_b = summarize 0 b
adamc@1017 517
adamc@1017 518 (*val () = Print.prefaces "Try"
adamc@1017 519 [("e", MonoPrint.p_exp env (e, ErrorMsg.dummySpan)),
adamc@1017 520 ("e'", MonoPrint.p_exp env e'),
adamc@1017 521 ("b", MonoPrint.p_exp (E.pushERel env x t NONE) b),
adamc@1017 522 ("e'_eff", p_events effs_e'),
adamc@1017 523 ("b_eff", p_events effs_b)]*)
adamc@1017 524
adamc@1017 525 fun does eff = List.exists (fn eff' => eff' = eff) effs_e'
adamc@1017 526 val writesPage = does WritePage
adamc@1017 527 val readsDb = does ReadDb
adamc@1017 528 val writesDb = does WriteDb
adamc@1017 529
adamc@1017 530 fun verifyUnused eff =
adamc@1017 531 case eff of
adamc@1017 532 UseRel => false
adamc@1017 533 | _ => true
adamc@1017 534
adamc@1017 535 fun verifyCompatible effs =
adamc@1017 536 case effs of
adamc@1017 537 [] => false
adamc@1017 538 | eff :: effs =>
adamc@1017 539 case eff of
adamc@1017 540 Unsure => false
adamc@1017 541 | UseRel => List.all verifyUnused effs
adamc@1017 542 | WritePage => not writesPage andalso verifyCompatible effs
adamc@1017 543 | ReadDb => not writesDb andalso verifyCompatible effs
adamc@1017 544 | WriteDb => not writesDb andalso not readsDb andalso verifyCompatible effs
adamc@1017 545 in
adamc@1017 546 (*Print.prefaces "verifyCompatible"
adamc@1017 547 [("e'", MonoPrint.p_exp env e'),
adamc@1017 548 ("b", MonoPrint.p_exp (E.pushERel env x t NONE) b),
adamc@1017 549 ("effs_e'", Print.p_list p_event effs_e'),
adamc@1017 550 ("effs_b", Print.p_list p_event effs_b)];*)
adamc@1017 551 if (List.null effs_e'
adamc@1017 552 orelse (List.all (fn eff => eff <> Unsure) effs_e'
adamc@1017 553 andalso verifyCompatible effs_b)
adamc@1017 554 orelse (case effs_b of
adamc@1017 555 UseRel :: effs => List.all verifyUnused effs
adamc@1017 556 | _ => false))
adamc@1017 557 andalso countFree 0 0 b = 1
adamc@1017 558 andalso not (freeInAbs b) then
adamc@1017 559 trySub ()
adamc@1017 560 else
adamc@1017 561 e
adamc@1017 562 end
adamc@1017 563 else
adamc@1017 564 trySub ()
adamc@1017 565 end
adamc@1017 566
adamc@470 567 val r =
adamc@470 568 case e of
adamc@470 569 ERel n =>
adamc@470 570 (case E.lookupERel env n of
adamc@470 571 (_, _, SOME e') => #1 e'
adamc@470 572 | _ => e)
adamc@470 573 | ENamed n =>
adamc@470 574 (case E.lookupENamed env n of
adamc@470 575 (_, _, SOME e', _) => ((*Print.prefaces "Switch" [("n", Print.PD.string (Int.toString n)),
adamc@470 576 ("e'", MonoPrint.p_exp env e')];*)
adamc@470 577 #1 e')
adamc@470 578 | _ => e)
adamc@470 579
adamc@470 580 | EApp ((EAbs (x, t, _, e1), loc), e2) =>
adamc@470 581 ((*Print.prefaces "Considering" [("e1", MonoPrint.p_exp (E.pushERel env x t NONE) e1),
adamc@694 582 ("e2", MonoPrint.p_exp env e2),
adamc@694 583 ("sub", MonoPrint.p_exp env (reduceExp env (subExpInExp (0, e2) e1)))];*)
adamc@975 584 if impure env e2 orelse countFree 0 0 e1 > 1 then
adamc@470 585 #1 (reduceExp env (ELet (x, t, e2, e1), loc))
adamc@470 586 else
adamc@470 587 #1 (reduceExp env (subExpInExp (0, e2) e1)))
adamc@470 588
adamc@470 589 | ECase (e', pes, {disc, result}) =>
adamc@442 590 let
adamc@470 591 fun push () =
adamc@470 592 case result of
adamc@470 593 (TFun (dom, result), loc) =>
adamc@1107 594 let
adamc@1107 595 fun safe (e, _) =
adamc@1107 596 case e of
adamc@1107 597 EAbs _ => true
adamc@1107 598 | _ => false
adamc@1107 599 in
adamc@1107 600 if List.all (safe o #2) pes then
adamc@1107 601 EAbs ("y", dom, result,
adamc@1107 602 (ECase (liftExpInExp 0 e',
adamc@1107 603 map (fn (p, (EAbs (_, _, _, e), _)) =>
adamc@1107 604 (p, swapExpVarsPat (0, patBinds p) e)
adamc@1107 605 | _ => raise Fail "MonoReduce ECase") pes,
adamc@1107 606 {disc = disc, result = result}), loc))
adamc@1107 607 else
adamc@1107 608 e
adamc@1107 609 end
adamc@470 610 | _ => e
adamc@318 611
adamc@470 612 fun search pes =
adamc@470 613 case pes of
adamc@470 614 [] => push ()
adamc@470 615 | (p, body) :: pes =>
adamc@814 616 case match ([], p, e') of
adamc@470 617 No => search pes
adamc@470 618 | Maybe => push ()
adamc@814 619 | Yes subs =>
adamc@800 620 let
adamc@829 621 val (body, remaining) =
adamc@829 622 foldl (fn (e, (body, remaining)) =>
adamc@829 623 (subExpInExp (0, multiLift remaining e) body, remaining - 1))
adamc@829 624 (body, length subs - 1) subs
adamc@920 625 val r = reduceExp (E.patBinds env p) body
adamc@800 626 in
adamc@829 627 (*Print.preface ("subs", Print.p_list (MonoPrint.p_exp env) subs);*)
adamc@800 628 (*Print.prefaces "ECase"
adamc@829 629 [("old", MonoPrint.p_exp env body),
adamc@829 630 ("body", MonoPrint.p_exp env body),
adamc@800 631 ("r", MonoPrint.p_exp env r)];*)
adamc@800 632 #1 r
adamc@800 633 end
adamc@470 634 in
adamc@941 635 if impure env e' then
adamc@941 636 e
adamc@941 637 else
adamc@941 638 search pes
adamc@470 639 end
adamc@318 640
adamc@470 641 | EField ((ERecord xes, _), x) =>
adamc@470 642 (case List.find (fn (x', _, _) => x' = x) xes of
adamc@470 643 SOME (_, e, _) => #1 e
adamc@470 644 | NONE => e)
adamc@398 645
adamc@470 646 | ELet (x1, t1, (ELet (x2, t2, e1, b1), loc), b2) =>
adamc@470 647 let
adamc@470 648 val e' = (ELet (x2, t2, e1,
adamc@470 649 (ELet (x1, t1, b1,
adamc@470 650 liftExpInExp 1 b2), loc)), loc)
adamc@442 651 in
adamc@470 652 (*Print.prefaces "ELet commute" [("e", MonoPrint.p_exp env (e, loc)),
adamc@470 653 ("e'", MonoPrint.p_exp env e')];*)
adamc@470 654 #1 (reduceExp env e')
adamc@470 655 end
adamc@470 656 | EApp ((ELet (x, t, e, b), loc), e') =>
adamc@470 657 #1 (reduceExp env (ELet (x, t, e,
adamc@470 658 (EApp (b, liftExpInExp 0 e'), loc)), loc))
adamc@470 659
adamc@1017 660 | ELet (x, t, e', b as (EAbs (x', t' as (TRecord [], _), ran, e''), loc)) =>
adamc@919 661 if impure env e' then
adamc@1017 662 doLet (x, t, e', b)
adamc@848 663 else
adamc@920 664 EAbs (x', t', ran, reduceExp (E.pushERel env x' t' NONE)
adamc@920 665 (ELet (x, t, liftExpInExp 0 e', swapExpVars 0 e''), loc))
adamc@470 666
adamc@1017 667 | ELet (x, t, e', b) => doLet (x, t, e', b)
adamc@252 668
adamc@470 669 | EStrcat ((EPrim (Prim.String s1), _), (EPrim (Prim.String s2), _)) =>
adamc@470 670 EPrim (Prim.String (s1 ^ s2))
adamc@268 671
adamc@572 672 | ESignalBind ((ESignalReturn e1, loc), e2) =>
adamc@572 673 #1 (reduceExp env (EApp (e2, e1), loc))
adamc@572 674
adamc@470 675 | _ => e
adamc@470 676 in
adamc@829 677 (*Print.prefaces "exp'" [("e", MonoPrint.p_exp env (e, ErrorMsg.dummySpan)),
adamc@829 678 ("r", MonoPrint.p_exp env (r, ErrorMsg.dummySpan))];*)
adamc@470 679 r
adamc@470 680 end
adamc@470 681
adamc@470 682 and bind (env, b) =
adamc@470 683 case b of
adamc@470 684 U.Decl.Datatype (x, n, xncs) => E.pushDatatype env x n xncs
adamc@470 685 | U.Decl.RelE (x, t) => E.pushERel env x t NONE
adamc@1017 686 | U.Decl.NamedE (x, n, t, eo, s) =>
adamc@1017 687 let
adamc@1017 688 val eo = case eo of
adamc@1017 689 NONE => NONE
adamc@1017 690 | SOME e => if mayInline (n, e) then
adamc@1017 691 SOME e
adamc@1017 692 else
adamc@1017 693 NONE
adamc@1017 694 in
adamc@1017 695 E.pushENamed env x n t (Option.map (reduceExp env) eo) s
adamc@1017 696 end
adamc@470 697
adamc@470 698 and reduceExp env = U.Exp.mapB {typ = typ, exp = exp, bind = bind} env
adamc@470 699
adamc@801 700 fun decl env d = ((*Print.preface ("d", MonoPrint.p_decl env (d, ErrorMsg.dummySpan));*)
adamc@801 701 d)
adamc@398 702 in
adamc@470 703 U.File.mapB {typ = typ, exp = exp, decl = decl, bind = bind} E.empty file
adamc@398 704 end
adamc@133 705
adamc@133 706 end