51 lines
1.5 KiB
Text
51 lines
1.5 KiB
Text
/-
|
|
Copyright (c) 2019 Microsoft Corporation. All rights reserved.
|
|
Released under Apache 2.0 license as described in the file LICENSE.
|
|
Authors: Leonardo de Moura
|
|
-/
|
|
prelude
|
|
import Init.Lean.Compiler.IR.Basic
|
|
import Init.Lean.Compiler.IR.FreeVars
|
|
|
|
namespace Lean
|
|
namespace IR
|
|
|
|
partial def reshapeWithoutDeadAux : Array FnBody → FnBody → IndexSet → FnBody
|
|
| bs, b, used =>
|
|
if bs.isEmpty then b
|
|
else
|
|
let curr := bs.back;
|
|
let bs := bs.pop;
|
|
let keep (_ : Unit) :=
|
|
let used := curr.collectFreeIndices used;
|
|
let b := curr.setBody b;
|
|
reshapeWithoutDeadAux bs b used;
|
|
let keepIfUsed (vidx : Index) :=
|
|
if used.contains vidx then keep ()
|
|
else reshapeWithoutDeadAux bs b used;
|
|
match curr with
|
|
| FnBody.vdecl x _ _ _ => keepIfUsed x.idx
|
|
| FnBody.jdecl j _ _ _ => keepIfUsed j.idx
|
|
| _ => keep ()
|
|
|
|
def reshapeWithoutDead (bs : Array FnBody) (term : FnBody) : FnBody :=
|
|
reshapeWithoutDeadAux bs term term.freeIndices
|
|
|
|
partial def FnBody.elimDead : FnBody → FnBody
|
|
| b =>
|
|
let (bs, term) := b.flatten;
|
|
let bs := modifyJPs bs FnBody.elimDead;
|
|
let term := match term with
|
|
| FnBody.case tid x xType alts =>
|
|
let alts := alts.map $ fun alt => alt.modifyBody FnBody.elimDead;
|
|
FnBody.case tid x xType alts
|
|
| other => other;
|
|
reshapeWithoutDead bs term
|
|
|
|
/-- Eliminate dead let-declarations and join points -/
|
|
def Decl.elimDead : Decl → Decl
|
|
| Decl.fdecl f xs t b => Decl.fdecl f xs t b.elimDead
|
|
| other => other
|
|
|
|
end IR
|
|
end Lean
|