From: Taylor R Campbell <campbell@mumble.net>
Date: Wed, 5 Dec 2018 05:56:55 +0000 (+0000)
Subject: x86 push can take a memory reference operand.
X-Git-Tag: mit-scheme-pucked-10.1.7~3^2~48
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=f206f4fa33916b4acef6e355c9e3cb92f849b9eb;p=mit-scheme.git

x86 push can take a memory reference operand.

Conveniently, it evaluates rsp before modifying it too.

Shaves about 1% off the runtime.
---

diff --git a/src/compiler/machines/x86-64/rules1.scm b/src/compiler/machines/x86-64/rules1.scm
index 787d50243..09a02bea7 100644
--- a/src/compiler/machines/x86-64/rules1.scm
+++ b/src/compiler/machines/x86-64/rules1.scm
@@ -285,6 +285,10 @@ USA.
   (with-unsigned-immediate-operand (make-non-pointer-literal type datum)
     (lambda (operand)
       (LAP (PUSH Q ,operand)))))
+
+(define-rule statement
+  (ASSIGN (PRE-INCREMENT (REGISTER 4) -1) (? expression rtl:simple-offset?))
+  (LAP (PUSH Q ,(offset->reference! expression))))
 
 ;;;; CHAR->ASCII/BYTE-OFFSET