From 06603b594a53c9c66c949b9a41dcf84dc84282ef Mon Sep 17 00:00:00 2001
From: Tom Jack <tom@tomjack.co>
Date: Mon, 25 Nov 2019 18:10:49 -0600
Subject: [PATCH] Mini_c: Identify more pure constants

---
 src/bin/expect_tests/contract_tests.ml  | 77 ++++++++++---------------
 src/passes/7-self_mini_c/self_mini_c.ml | 25 ++++++--
 2 files changed, 53 insertions(+), 49 deletions(-)

diff --git a/src/bin/expect_tests/contract_tests.ml b/src/bin/expect_tests/contract_tests.ml
index 2dbe3ad34..485d91c8b 100644
--- a/src/bin/expect_tests/contract_tests.ml
+++ b/src/bin/expect_tests/contract_tests.ml
@@ -5,7 +5,7 @@ let contract basename =
 
 let%expect_test _ =
   run_ligo_good [ "measure-contract" ; contract "coase.ligo" ; "main" ] ;
-  [%expect {| 2068 bytes |}] ;
+  [%expect {| 2066 bytes |}] ;
 
   run_ligo_good [ "measure-contract" ; contract "multisig.ligo" ; "main" ] ;
   [%expect {| 1093 bytes |}] ;
@@ -14,7 +14,7 @@ let%expect_test _ =
   [%expect {| 627 bytes |}] ;
 
   run_ligo_good [ "measure-contract" ; contract "vote.mligo" ; "main" ] ;
-  [%expect {| 714 bytes |}] ;
+  [%expect {| 628 bytes |}] ;
 
   ()
 
@@ -204,10 +204,9 @@ let%expect_test _ =
                      NIL operation ;
                      SWAP ;
                      CONS ;
-                     DUP ;
-                     DIP { DIP 8 { DUP } ; DIG 8 } ;
+                     DIP { DIP 7 { DUP } ; DIG 7 } ;
                      PAIR ;
-                     DIP { DROP 12 } } ;
+                     DIP { DROP 11 } } ;
                  DIP { DROP } }
                { DUP ;
                  DIP { DIP { DUP } ; SWAP } ;
@@ -482,35 +481,28 @@ let%expect_test _ =
              CAR ;
              IF_LEFT
                { DUP ;
-                 PUSH int 0 ;
-                 SOME ;
+                 DUP ;
+                 CAR ;
+                 CAR ;
                  DIP { PUSH int 0 ;
                        SOME ;
-                       EMPTY_MAP string int ;
-                       SWAP ;
-                       PUSH string "Yes" ;
+                       DIP { PUSH int 0 ;
+                             SOME ;
+                             EMPTY_MAP string int ;
+                             SWAP ;
+                             PUSH string "Yes" ;
+                             UPDATE } ;
+                       PUSH string "No" ;
                        UPDATE } ;
-                 PUSH string "No" ;
-                 UPDATE ;
-                 DIP { DUP } ;
-                 SWAP ;
-                 CAR ;
-                 CAR ;
-                 DIP { DUP } ;
                  PAIR ;
-                 DIP { DIP { DUP } ;
-                       SWAP ;
-                       CAR ;
-                       CDR ;
-                       DIP { DIP { DUP } ; SWAP ; CDR } ;
-                       PAIR } ;
+                 DIP { DUP ; CAR ; CDR ; DIP { DUP ; CDR } ; PAIR } ;
                  PAIR ;
                  EMPTY_SET address ;
                  SWAP ;
                  PAIR ;
                  NIL operation ;
                  PAIR ;
-                 DIP { DROP 3 } }
+                 DIP { DROP 2 } }
                { DUP ;
                  DIP { DIP { DUP } ; SWAP ; CDR } ;
                  PAIR ;
@@ -519,41 +511,36 @@ let%expect_test _ =
                  DIP { DUP } ;
                  SWAP ;
                  CDR ;
-                 NOW ;
-                 SOURCE ;
-                 DIP 3 { DUP } ;
-                 DIG 3 ;
-                 DIP { DIP 2 { DUP } ; DIG 2 ; CAR ; CAR ; CDR } ;
+                 DIP { DUP } ;
+                 SWAP ;
+                 DIP { DUP ; CAR ; CAR ; CDR } ;
                  GET ;
                  IF_NONE { PUSH string "MAP FIND" ; FAILWITH } {} ;
-                 DIP 3 { DUP } ;
-                 DIG 3 ;
+                 DIP { DUP } ;
+                 SWAP ;
                  CAR ;
                  CAR ;
                  CAR ;
-                 DIP { DIP 4 { DUP } ;
-                       DIG 4 ;
+                 DIP { DIP 2 { DUP } ;
+                       DIG 2 ;
                        DIP { DUP ;
                              PUSH int 1 ;
                              ADD ;
                              SOME ;
-                             DIP { DIP 3 { DUP } ; DIG 3 ; CAR ; CAR ; CDR } } ;
+                             DIP { DIP { DUP } ; SWAP ; CAR ; CAR ; CDR } } ;
                        UPDATE } ;
                  PAIR ;
-                 DIP { DIP 3 { DUP } ;
-                       DIG 3 ;
-                       CAR ;
-                       CDR ;
-                       CAR ;
-                       DIP { DIP 3 { DUP } ; DIG 3 ; CAR ; CDR ; CDR } ;
-                       PAIR } ;
-                 PAIR ;
                  DIP { DIP { DUP } ;
                        SWAP ;
-                       DIP { DIP 3 { DUP } ; DIG 3 ; CDR ; PUSH bool True } ;
-                       UPDATE } ;
+                       CAR ;
+                       CDR ;
+                       CAR ;
+                       DIP { DIP { DUP } ; SWAP ; CAR ; CDR ; CDR } ;
+                       PAIR } ;
+                 PAIR ;
+                 DIP { DIP { DUP } ; SWAP ; CDR ; PUSH bool True ; SOURCE ; UPDATE } ;
                  PAIR ;
                  NIL operation ;
                  PAIR ;
-                 DIP { DROP 7 } } ;
+                 DIP { DROP 5 } } ;
              DIP { DROP } } } |}]
diff --git a/src/passes/7-self_mini_c/self_mini_c.ml b/src/passes/7-self_mini_c/self_mini_c.ml
index 4dbd2573b..8f1df9053 100644
--- a/src/passes/7-self_mini_c/self_mini_c.ml
+++ b/src/passes/7-self_mini_c/self_mini_c.ml
@@ -17,12 +17,29 @@ let map_expression :
    assuming arguments are pure *)
 let is_pure_constant : string -> bool =
   function
-  | "CAR"
-  | "CDR"
-  | "PAIR"
+  | "UNIT"
+  | "CAR" | "CDR" | "PAIR"
+  | "NIL" | "CONS"
+  | "NEG" | "OR" | "AND" | "XOR" | "NOT"
+  | "EQ" | "NEQ" | "LT" | "LE" | "GT" | "GE"
+  | "SOME"
+  | "UPDATE" | "MAP_GET" | "MAP_FIND_OPT" | "MAP_ADD" | "MAP_UPDATE"
+  | "INT" | "ABS" | "ISNAT"
+  | "BALANCE" | "AMOUNT" | "ADDRESS" | "NOW" | "SOURCE" | "SENDER" | "CHAIN_ID"
+  | "SET_MEM" | "SET_ADD" | "SET_REMOVE" | "SLICE"
+  | "SHA256" | "SHA512" | "BLAKE2B" | "CHECK_SIGNATURE"
+  | "HASH_KEY" | "PACK" | "CONCAT"
     -> true
+  (* unfortunately impure: *)
+  | "ADD"|"SUB"|"TIMES"|"DIV"|"MOD"
+  (* impure: *)
+  | "ASSERT" | "ASSERT_INFERRED"
+  | "MAP_GET_FORCE" | "MAP_FIND"
+  | "FOLD_WHILE"
+  | "CALL"
   (* TODO... *)
-  | _ -> false
+  | _
+    -> false
 
 let rec is_pure : expression -> bool = fun e ->
   match e.content with