From c7744fae69b314f1eaf68b2b60de3e90d4cad264 Mon Sep 17 00:00:00 2001
From: felix <address@hidden>
Date: Wed, 18 Sep 2019 14:59:51 +0200
Subject: [PATCH] Revert "Revert half of "Add some optimizer simplification
 rules""

This reverts commit d8727f4a9bdfded30813a5a433b57eddf60c068f.
---
 optimizer.scm | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/optimizer.scm b/optimizer.scm
index bd163710..fc2d3165 100644
--- a/optimizer.scm
+++ b/optimizer.scm
@@ -830,6 +830,38 @@
                                    args1)
                                  nargs)
                            #t))
+                    (else (loop (cdr args)
+                                (cons (car args) nargs)
+                                ok)))))))
+
+ ;; (let ((<var1> (##core#inline <op> ...)))
+ ;;   (<var2> ... <var1> ...))
+ ;; -> (<var2> ... (##core#inline <op> ...) ...)
+ ;;                                  ...))
+ ;; - <var1> is used only once.
+ `((let (var) (##core#inline (op) . args1)
+      (##core#call p . args2))
+    (var op args1 p args2)
+    ,(lambda (db may-rewrite var op args1 p args2)
+       (and may-rewrite   ; give other optimizations a chance first
+            (= 1 (length (db-get-list db var 'references)))
+            (let loop ((args args2) (nargs '()) (ok #f))
+              (cond ((null? args)
+                     (and ok
+                          (make-node 
+                           '##core#call p
+                           (reverse nargs))))
+                    ((and (eq? '##core#variable
+                               (node-class (car args)))
+                          (eq? var
+                               (car (node-parameters (car args)))))
+                     (loop (cdr args)
+                           (cons (make-node
+                                   '##core#inline
+                                   (list op)
+                                   args1)
+                                 nargs)
+                           #t))
                     (else (loop (cdr args)
                                 (cons (car args) nargs)
                                 ok))))))))
-- 
2.19.1