From: Taylor R Campbell <campbell@mumble.net>
Date: Sat, 29 Dec 2018 21:57:47 +0000 (+0000)
Subject: Relax register constraints for tagging rule.
X-Git-Tag: mit-scheme-pucked-10.1.20~11^2~80^2~15
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=2d961c10171d94ca82a6bdf7c61aad9fbadc9da1;p=mit-scheme.git

Relax register constraints for tagging rule.

No need to keep the source alive here -- use move-to-target and allow
any temporary register instead.
---

diff --git a/src/compiler/machines/x86-64/rules1.scm b/src/compiler/machines/x86-64/rules1.scm
index 5f6acf4d0..8dd0daddc 100644
--- a/src/compiler/machines/x86-64/rules1.scm
+++ b/src/compiler/machines/x86-64/rules1.scm
@@ -110,10 +110,10 @@ USA.
 	  (CONS-POINTER (MACHINE-CONSTANT (? type)) (REGISTER (? datum))))
   (if (zero? type)
       (assign-register->register target datum)
-      (let* ((datum (source-register-reference datum))
-	     (target (target-register-reference target)))
-	(LAP (MOV Q ,target (&U ,(make-non-pointer-literal type 0)))
-	     (OR Q ,target ,datum)))))
+      (let* ((target (standard-move-to-target! datum target))
+	     (temp (temporary-register-reference)))
+	(LAP (MOV Q ,temp (&U ,(make-non-pointer-literal type 0)))
+	     (OR Q ,target ,temp)))))
 
 #| This doesn't work because immediate operands aren't big enough to
    fit the type tag.