adamc@482: (* Copyright (c) 2008, Adam Chlipala adamc@482: * All rights reserved. adamc@482: * adamc@482: * Redistribution and use in source and binary forms, with or without adamc@482: * modification, are permitted provided that the following conditions are met: adamc@482: * adamc@482: * - Redistributions of source code must retain the above copyright notice, adamc@482: * this list of conditions and the following disclaimer. adamc@482: * - Redistributions in binary form must reproduce the above copyright notice, adamc@482: * this list of conditions and the following disclaimer in the documentation adamc@482: * and/or other materials provided with the distribution. adamc@482: * - The names of contributors may not be used to endorse or promote products adamc@482: * derived from this software without specific prior written permission. adamc@482: * adamc@482: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" adamc@482: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE adamc@482: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE adamc@482: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE adamc@482: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR adamc@482: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF adamc@482: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS adamc@482: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN adamc@482: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) adamc@482: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE adamc@482: * POSSIBILITY OF SUCH DAMAGE. adamc@482: *) adamc@482: adamc@482: (* Simplify a Core program algebraically, without unfolding definitions *) adamc@482: adamc@482: structure ReduceLocal :> REDUCE_LOCAL = struct adamc@482: adamc@482: open Core adamc@482: adamc@512: structure IM = IntBinaryMap adamc@482: adamc@1062: fun multiLiftExpInExp n e = adamc@1062: if n = 0 then adamc@1062: e adamc@1062: else adamc@1062: multiLiftExpInExp (n - 1) (CoreEnv.liftExpInExp 0 e) adamc@1062: adamc@512: datatype env_item = adamc@512: Unknown adamc@512: | Known of exp adamc@482: adamc@512: | Lift of int adamc@482: adamc@512: type env = env_item list adamc@512: adamc@512: val deKnown = List.filter (fn Known _ => false adamc@512: | _ => true) adamc@512: adamc@1062: datatype result = Yes of env | No | Maybe adamc@1062: adamc@1062: fun match (env, p : pat, e : exp) = adamc@1062: let adamc@1062: val baseline = length env adamc@1062: adamc@1062: fun match (env, p, e) = adamc@1062: case (#1 p, #1 e) of adamc@1062: (PWild, _) => Yes env adamc@1062: | (PVar (x, t), _) => Yes (Known (multiLiftExpInExp (length env - baseline) e) :: env) adamc@1062: adamc@1062: | (PPrim p, EPrim p') => adamc@1062: if Prim.equal (p, p') then adamc@1062: Yes env adamc@1062: else adamc@1062: No adamc@1062: adamc@1062: | (PCon (_, PConVar n1, _, NONE), ECon (_, PConVar n2, _, NONE)) => adamc@1062: if n1 = n2 then adamc@1062: Yes env adamc@1062: else adamc@1062: No adamc@1062: adamc@1062: | (PCon (_, PConVar n1, _, SOME p), ECon (_, PConVar n2, _, SOME e)) => adamc@1062: if n1 = n2 then adamc@1062: match (env, p, e) adamc@1062: else adamc@1062: No adamc@1062: adamc@1062: | (PCon (_, PConFfi {mod = m1, con = con1, ...}, _, NONE), adamc@1062: ECon (_, PConFfi {mod = m2, con = con2, ...}, _, NONE)) => adamc@1062: if m1 = m2 andalso con1 = con2 then adamc@1062: Yes env adamc@1062: else adamc@1062: No adamc@1062: adamc@1062: | (PCon (_, PConFfi {mod = m1, con = con1, ...}, _, SOME ep), adamc@1062: ECon (_, PConFfi {mod = m2, con = con2, ...}, _, SOME e)) => adamc@1062: if m1 = m2 andalso con1 = con2 then adamc@1062: match (env, p, e) adamc@1062: else adamc@1062: No adamc@1062: adamc@1062: | (PRecord xps, ERecord xes) => adamc@1062: if List.exists (fn ((CName _, _), _, _) => false adamc@1062: | _ => true) xes then adamc@1062: Maybe adamc@1062: else adamc@1062: let adamc@1062: fun consider (xps, env) = adamc@1062: case xps of adamc@1062: [] => Yes env adamc@1062: | (x, p, _) :: rest => adamc@1062: case List.find (fn ((CName x', _), _, _) => x' = x adamc@1062: | _ => false) xes of adamc@1062: NONE => No adamc@1062: | SOME (_, e, _) => adamc@1062: case match (env, p, e) of adamc@1062: No => No adamc@1062: | Maybe => Maybe adamc@1062: | Yes env => consider (rest, env) adamc@1062: in adamc@1062: consider (xps, env) adamc@1062: end adamc@1062: adamc@1062: | _ => Maybe adamc@1062: in adamc@1062: match (env, p, e) adamc@1062: end adamc@1062: adamc@512: fun exp env (all as (e, loc)) = adamc@512: case e of adamc@512: EPrim _ => all adamc@512: | ERel n => adamc@512: let adamc@512: fun find (n', env, nudge, lift) = adamc@512: case env of adamc@642: [] => (ERel (n + nudge), loc) adamc@512: | Lift lift' :: rest => find (n', rest, nudge + lift', lift + lift') adamc@512: | Unknown :: rest => adamc@512: if n' = 0 then adamc@512: (ERel (n + nudge), loc) adamc@512: else adamc@512: find (n' - 1, rest, nudge, lift + 1) adamc@512: | Known e :: rest => adamc@512: if n' = 0 then adamc@512: ((*print "SUBSTITUTING\n";*) adamc@512: exp (Lift lift :: rest) e) adamc@512: else adamc@512: find (n' - 1, rest, nudge - 1, lift) adamc@512: in adamc@512: find (n, env, 0, 0) adamc@512: end adamc@512: | ENamed _ => all adamc@512: | ECon (dk, pc, cs, eo) => (ECon (dk, pc, cs, Option.map (exp env) eo), loc) adamc@512: | EFfi _ => all adamc@512: | EFfiApp (m, f, es) => (EFfiApp (m, f, map (exp env) es), loc) adamc@512: adamc@721: | EApp ((ECApp ((ECAbs (_, _, (EAbs (_, (CRel 0, _), _, adamc@721: (ECon (dk, pc, [(CRel 0, loc)], SOME (ERel 0, _)), _)), _)), _), adamc@721: t), _), e) => adamc@721: (ECon (dk, pc, [t], SOME (exp env e)), loc) adamc@721: adamc@512: | EApp (e1, e2) => adamc@512: let adamc@512: val e1 = exp env e1 adamc@512: val e2 = exp env e2 adamc@512: in adamc@512: case #1 e1 of adamc@512: EAbs (_, _, _, b) => exp (Known e2 :: deKnown env) b adamc@512: | _ => (EApp (e1, e2), loc) adamc@512: end adamc@512: adamc@512: | EAbs (x, dom, ran, e) => (EAbs (x, dom, ran, exp (Unknown :: env) e), loc) adamc@512: adamc@721: | ECApp ((ECAbs (_, _, (ECon (dk, pc, [(CRel 0, loc)], NONE), _)), _), t) => adamc@721: (ECon (dk, pc, [t], NONE), loc) adamc@721: adamc@512: | ECApp (e, c) => (ECApp (exp env e, c), loc) adamc@626: | ECAbs (x, k, e) => (ECAbs (x, k, exp env e), loc) adamc@512: adamc@626: | EKApp (e, k) => (EKApp (exp env e, k), loc) adamc@626: | EKAbs (x, e) => (EKAbs (x, exp env e), loc) adamc@512: adamc@512: | ERecord xcs => (ERecord (map (fn (x, e, t) => (x, exp env e, t)) xcs), loc) adamc@512: | EField (e, c, others) => adamc@512: let adamc@512: val e = exp env e adamc@512: adamc@512: fun default () = (EField (e, c, others), loc) adamc@512: in adamc@512: case (#1 e, #1 c) of adamc@512: (ERecord xcs, CName x) => adamc@512: (case List.find (fn ((CName x', _), _, _) => x' = x | _ => false) xcs of adamc@512: NONE => default () adamc@512: | SOME (_, e, _) => e) adamc@512: | _ => default () adamc@512: end adamc@512: adamc@512: | EConcat (e1, c1, e2, c2) => (EConcat (exp env e1, c1, exp env e2, c2), loc) adamc@512: | ECut (e, c, others) => (ECut (exp env e, c, others), loc) adamc@512: | ECutMulti (e, c, others) => (ECutMulti (exp env e, c, others), loc) adamc@512: adamc@512: | ECase (e, pes, others) => adamc@512: let adamc@512: fun patBinds (p, _) = adamc@512: case p of adamc@512: PWild => 0 adamc@512: | PVar _ => 1 adamc@512: | PPrim _ => 0 adamc@512: | PCon (_, _, _, NONE) => 0 adamc@512: | PCon (_, _, _, SOME p) => patBinds p adamc@512: | PRecord xpts => foldl (fn ((_, p, _), n) => n + patBinds p) 0 xpts adamc@1062: adamc@1062: fun push () = adamc@1062: (ECase (exp env e, adamc@1062: map (fn (p, e) => (p, adamc@1062: exp (List.tabulate (patBinds p, adamc@1062: fn _ => Unknown) @ env) e)) adamc@1062: pes, others), loc) adamc@1062: adamc@1062: fun search pes = adamc@1062: case pes of adamc@1062: [] => push () adamc@1062: | (p, body) :: pes => adamc@1062: case match (env, p, e) of adamc@1062: No => search pes adamc@1062: | Maybe => push () adamc@1062: | Yes env' => exp env' body adamc@512: in adamc@1062: search pes adamc@512: end adamc@512: adamc@512: | EWrite e => (EWrite (exp env e), loc) adamc@512: | EClosure (n, es) => (EClosure (n, map (exp env) es), loc) adamc@512: adamc@512: | ELet (x, t, e1, e2) => (ELet (x, t, exp env e1, exp (Unknown :: env) e2), loc) adamc@512: adamc@1020: | EServerCall (n, es, t) => (EServerCall (n, map (exp env) es, t), loc) adamc@607: adamc@512: fun reduce file = adamc@482: let adamc@512: fun doDecl (d as (_, loc)) = adamc@512: case #1 d of adamc@512: DCon _ => d adamc@512: | DDatatype _ => d adamc@512: | DVal (x, n, t, e, s) => adamc@512: let adamc@512: val e = exp [] e adamc@512: in adamc@512: (DVal (x, n, t, e, s), loc) adamc@512: end adamc@512: | DValRec vis => adamc@512: (DValRec (map (fn (x, n, t, e, s) => (x, n, t, exp [] e, s)) vis), loc) adamc@512: | DExport _ => d adamc@512: | DTable _ => d adamc@512: | DSequence _ => d adamc@754: | DView _ => d adamc@512: | DDatabase _ => d adamc@512: | DCookie _ => d adamc@718: | DStyle _ => d adamc@482: in adamc@512: map doDecl file adamc@482: end adamc@482: adamc@642: val reduceExp = exp [] adamc@642: adamc@482: end