From 6f919635dafa5c57d8ba53f193c88ecdcc0d4e85 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Thu, 5 Dec 2019 07:06:28 -0700
Subject: [PATCH] schmeify: improve determinism by ordering lifted procedures

---
 racket/src/schemify/lift.rkt | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/racket/src/schemify/lift.rkt b/racket/src/schemify/lift.rkt
index acfcdd3f86..34ee66e819 100644
--- a/racket/src/schemify/lift.rkt
+++ b/racket/src/schemify/lift.rkt
@@ -620,23 +620,25 @@
   ;; Create bindings for lifted functions, adding new arguments
   ;; as the functions are lifted
   (define (extract-lifted-bindings lifts empties)
-    (for/list ([(f proc) (in-hash lifts)]
-               #:when (liftable? proc))
-      (let* ([new-args (liftable-frees proc)]
-             [frees (for/hash ([arg (in-list new-args)])
-                      (values arg #t))]
-             [rhs (liftable-expr proc)])
-        `[,f ,(match rhs
-                [`(lambda ,args . ,body)
-                 (let ([body (convert-lifted-calls-in-seq/box-mutated body args lifts frees empties)])
-                   (reannotate rhs `(lambda ,(append new-args args) . ,body)))]
-                [`(case-lambda [,argss . ,bodys] ...)
-                 (reannotate rhs `(case-lambda
-                                    ,@(for/list ([args (in-list argss)]
-                                                 [body (in-list bodys)])
-                                        (let ([body (convert-lifted-calls-in-seq/box-mutated body args lifts frees empties)])
-                                          `[,(append new-args args) . ,body]))))])])))
-
+    (define bindings
+      (for/list ([(f proc) (in-hash lifts)]
+                 #:when (liftable? proc))
+        (let* ([new-args (liftable-frees proc)]
+               [frees (for/hash ([arg (in-list new-args)])
+                        (values arg #t))]
+               [rhs (liftable-expr proc)])
+          `[,f ,(match rhs
+                  [`(lambda ,args . ,body)
+                   (let ([body (convert-lifted-calls-in-seq/box-mutated body args lifts frees empties)])
+                     (reannotate rhs `(lambda ,(append new-args args) . ,body)))]
+                  [`(case-lambda [,argss . ,bodys] ...)
+                   (reannotate rhs `(case-lambda
+                                      ,@(for/list ([args (in-list argss)]
+                                                   [body (in-list bodys)])
+                                          (let ([body (convert-lifted-calls-in-seq/box-mutated body args lifts frees empties)])
+                                            `[,(append new-args args) . ,body]))))])])))
+    ;; Improve determinsism:
+    (sort bindings symbol<? #:key car))
 
   ;; ----------------------------------------
   ;; Helpers