From 1fc263ec0f527698b2f4d734d9757c9f723d0bee Mon Sep 17 00:00:00 2001
From: Son Ho
Date: Mon, 18 Sep 2023 12:25:40 +0200
Subject: Improve scalar_tac

---
 backends/lean/Base/Arith/Int.lean    |  8 +++++---
 backends/lean/Base/Arith/Scalar.lean | 17 +++++++++++++++--
 2 files changed, 20 insertions(+), 5 deletions(-)

(limited to 'backends/lean/Base/Arith')

diff --git a/backends/lean/Base/Arith/Int.lean b/backends/lean/Base/Arith/Int.lean
index eb6701c2..3359ecdb 100644
--- a/backends/lean/Base/Arith/Int.lean
+++ b/backends/lean/Base/Arith/Int.lean
@@ -211,9 +211,11 @@ def intTacPreprocess (extraPreprocess :  Tactic.TacticM Unit) : Tactic.TacticM U
   let _ ← introHasIntPropInstances
   -- Extra preprocessing, before we split on the disjunctions
   extraPreprocess
-  -- Split
-  let asms ← introInstances ``PropHasImp.concl lookupPropHasImp
-  splitOnAsms asms.toList
+  -- Split - note that the extra-preprocessing step might actually have
+  -- proven the goal (by doing simplifications for instance)
+  Tactic.allGoals do
+    let asms ← introInstances ``PropHasImp.concl lookupPropHasImp
+    splitOnAsms asms.toList
 
 elab "int_tac_preprocess" : tactic =>
   intTacPreprocess (do pure ())
diff --git a/backends/lean/Base/Arith/Scalar.lean b/backends/lean/Base/Arith/Scalar.lean
index db672489..47751c8a 100644
--- a/backends/lean/Base/Arith/Scalar.lean
+++ b/backends/lean/Base/Arith/Scalar.lean
@@ -16,14 +16,15 @@ def scalarTacExtraPreprocess : Tactic.TacticM Unit := do
    add (← mkAppM ``Scalar.cMin_bound #[.const ``ScalarTy.Isize []])
    add (← mkAppM ``Scalar.cMax_bound #[.const ``ScalarTy.Usize []])
    add (← mkAppM ``Scalar.cMax_bound #[.const ``ScalarTy.Isize []])
-   -- Reveal the concrete bounds
+   -- Reveal the concrete bounds, simplify calls to [ofInt]
    Utils.simpAt [``Scalar.min, ``Scalar.max, ``Scalar.cMin, ``Scalar.cMax,
                  ``I8.min, ``I16.min, ``I32.min, ``I64.min, ``I128.min,
                  ``I8.max, ``I16.max, ``I32.max, ``I64.max, ``I128.max,
                  ``U8.min, ``U16.min, ``U32.min, ``U64.min, ``U128.min,
                  ``U8.max, ``U16.max, ``U32.max, ``U64.max, ``U128.max,
                  ``Usize.min
-                 ] [] [] .wildcard
+                 ] [``Scalar.ofInt_val_eq, ``Scalar.neq_to_neq_val] [] .wildcard
+   
 
 elab "scalar_tac_preprocess" : tactic =>
   intTacPreprocess scalarTacExtraPreprocess
@@ -50,4 +51,16 @@ example (x y : U32) : x.val ≤ Scalar.max ScalarTy.U32 := by
 example (x : U32 × U32) : 0 ≤ x.fst.val := by
   scalar_tac
 
+-- Checking that we properly handle [ofInt]
+example : U32.ofInt 1 ≤ U32.max := by
+  scalar_tac
+
+example (x : Int) (h0 : 0 ≤ x) (h1 : x ≤ U32.max) :
+  U32.ofInt x (by constructor <;> scalar_tac) ≤ U32.max := by
+  scalar_tac
+
+-- Not equal
+example (x : U32) (h0 : ¬ x = U32.ofInt 0) : 0 < x.val := by
+  scalar_tac
+
 end Arith
-- 
cgit v1.2.3