52b1b342ab
This PR implements zero cost `BaseIO` by erasing the `IO.RealWorld` parameter from argument lists and structures. This is a **major breaking change for FFI**. Concretely: - `BaseIO` is defined in terms of `ST IO.RealWorld` - `EIO` (and thus `IO`) is defined in terms of `EST IO.RealWorld` - The opaque `Void` type is introduced and the trivial structure optimization updated to account for it. Furthermore, arguments of type `Void s` are removed from the argument lists of the C functions. - `ST` is redefined as `Void s -> ST.Out s a` where `ST.Out` is a pair of `Void s` and `a` This together has the following major effects on our generated code: - Functions that return `BaseIO`/`ST`/`EIO`/`IO`/`EST` now do not take the dummy world parameter anymore. To account for this FFI code needs to delete the dummy world parameter from the argument lists. - Functions that return `BaseIO`/`ST` now return their wrapped value directly. In particular `BaseIO UInt32` now returns a `uint32_t` instead of a `lean_object*`. To account for this FFI code might have to change the return type and does not need to call `lean_io_result_mk_ok` anymore but can instead just `return` values right away (same with extracting values from `BaseIO` computations. - Functions that return `EIO`/`IO`/`EST` now only return the equivalent of an `Except` node which reduces the allocation size. The `lean_io_result_mk_ok`/`lean_io_result_mk_error` functions were updated to account for this already so no change is required. Besides improving performance by dropping allocation (sizes) we can now also do fun new things such as: ```lean @[extern "malloc"] opaque malloc (size : USize) : BaseIO USize ```
83 lines
3.4 KiB
Text
83 lines
3.4 KiB
Text
import Lean
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/-- `erased α` is the same as `α`, except that the elements
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of `erased α` are erased in the VM in the same way as types
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and proofs. This can be used to track data without storing it
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literally. -/
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def Erased (α : Sort u) : Sort max 1 u :=
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Σ's : α → Prop, ∃ a, (fun b => a = b) = s
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namespace Erased
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/-- Erase a value. -/
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@[inline]
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def mk {α} (a : α) : Erased α :=
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⟨fun b => a = b, a, rfl⟩
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open Lean.Compiler
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set_option pp.explicit true
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set_option pp.funBinderTypes true
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set_option pp.letVarTypes true
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set_option trace.Compiler.result true
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/--
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trace: [Compiler.result] size: 1
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def Erased.mk (α : lcErased) (a : lcAny) : PSigma lcErased lcAny :=
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let _x.1 : PSigma lcErased lcAny := PSigma.mk ◾ ◾ ◾ ◾;
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return _x.1
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---
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trace: [Compiler.result] size: 5
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def _private.lean.run.erased.0._eval._lam_0 (_x.1 : Array
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Lean.Name) (_x.2 : PUnit) (_y.3 : Lean.Elab.Term.Context) (_y.4 : lcAny) (_y.5 : Lean.Meta.Context) (_y.6 : lcAny) (_y.7 : Lean.Core.Context) (_y.8 : lcAny) (_y.9 : lcVoid) : EST.Out
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Lean.Exception lcAny PUnit :=
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let _x.10 : EST.Out Lean.Exception lcAny PUnit := compile _x.1 _y.7 _y.8 _y.9;
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cases _x.10 : EST.Out Lean.Exception lcAny PUnit
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| EST.Out.ok (a.11 : PUnit) (a.12 : lcVoid) =>
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let _x.13 : EST.Out Lean.Exception lcAny PUnit := @EST.Out.ok ◾ ◾ ◾ _x.2 a.12;
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return _x.13
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| EST.Out.error (a.14 : Lean.Exception) (a.15 : lcVoid) =>
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return _x.10
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[Compiler.result] size: 1
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def _private.lean.run.erased.0._eval._closed_0 : String :=
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let _x.1 : String := "Erased";
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return _x.1
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[Compiler.result] size: 1
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def _private.lean.run.erased.0._eval._closed_1 : String :=
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let _x.1 : String := "mk";
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return _x.1
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[Compiler.result] size: 3
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def _private.lean.run.erased.0._eval._closed_2 : Lean.Name :=
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let _x.1 : String := _eval._closed_1.2;
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let _x.2 : String := _eval._closed_0.2;
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let _x.3 : Lean.Name := Lean.Name.mkStr2 _x.2 _x.1;
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return _x.3
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[Compiler.result] size: 2
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def _private.lean.run.erased.0._eval._closed_3 : Array Lean.Name :=
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let _x.1 : Nat := 1;
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let _x.2 : Array Lean.Name := Array.mkEmpty ◾ _x.1;
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return _x.2
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[Compiler.result] size: 3
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def _private.lean.run.erased.0._eval._closed_4 : Array Lean.Name :=
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let _x.1 : Lean.Name := _eval._closed_2.2;
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let _x.2 : Array Lean.Name := _eval._closed_3.2;
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let _x.3 : Array Lean.Name := Array.push ◾ _x.2 _x.1;
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return _x.3
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[Compiler.result] size: 9
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def _private.lean.run.erased.0._eval (a.1 : Lean.Elab.Command.Context) (a.2 : lcAny) (a.3 : lcVoid) : EST.Out
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Lean.Exception lcAny PUnit :=
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let _x.4 : String := _eval._closed_0.2;
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let _x.5 : String := _eval._closed_1.2;
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let _x.6 : Lean.Name := _eval._closed_2.2;
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let _x.7 : Nat := 1;
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let _x.8 : Array Lean.Name := _eval._closed_3.2;
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let _x.9 : Array Lean.Name := _eval._closed_4.2;
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let _x.10 : PUnit := PUnit.unit;
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let _f.11 : Lean.Elab.Term.Context →
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lcAny →
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Lean.Meta.Context →
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lcAny →
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Lean.Core.Context → lcAny → lcVoid → EST.Out Lean.Exception lcAny PUnit := _eval._lam_0.2 _x.9 _x.10;
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let _x.12 : EST.Out Lean.Exception lcAny PUnit := Lean.Elab.Command.liftTermElabM._redArg _f.11 a.1 a.2 a.3;
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return _x.12
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-/
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#guard_msgs in
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run_meta Lean.Compiler.compile #[``Erased.mk]
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