Changeset 11421

Timestamp:

Nov 24, 2008, 8:11:06 PM (12 years ago)

Author:

rme

Message:

In ALLOC-C-FRAME and ALLOC-VARIABLE-C-FRAME, work around a Darwin bug
by leaving an extra word of space in the parameter area.

(Supersedes r11414, which reserved even more extra space.)

File:

• trunk/source/compiler/X86/X8632/x8632-vinsns.lisp (modified) (2 diffs)

trunk/source/compiler/X86/X8632/x8632-vinsns.lisp

@@ -3686 +3686 @@
                                    ((temp :imm)))
   (movd (:@ (:%seg :rcontext) x8632::tcr.foreign-sp) (:%mmx x8632::stack-temp))
-  ;; make frame at least 24 bytes long
-  (subl (:$l (:apply ash (:apply max 6 nwords) x8632::word-shift))
+  ;; Work around Apple bug number 6386516 (open stub may clobber stack)
+  ;; by leaving an extra word of space in the parameter area.
+  (subl (:$l (:apply ash (:apply 1+ nwords) x8632::word-shift))
         (:@ (:%seg :rcontext) x8632::tcr.foreign-sp))
   ;; align stack to 16-byte boundary
@@ -3700 +3701 @@
                                             ((temp :imm)))
   (movd (:@ (:%seg :rcontext) x8632::tcr.foreign-sp) (:%mmx x8632::stack-temp))
-  ;; make frame at least 24 bytes long (note that nwords is a fixnum)
-  (movl (:$l 24) (:%l temp))
-  (rcmpl (:%l nwords) (:%l temp))
-  (cmoval (:%l nwords) (:%l temp))
+  ;; Work around Apple bug number 6386516 (open stub may clobber stack)
+  ;; by leaving an extra word of space in the parameter area.
+  ;; Note that nwords is a fixnum.
+  (leal (:@ 4 (:%l nwords)) (:%l temp))
   (subl (:%l temp) (:@ (:%seg :rcontext) x8632::tcr.foreign-sp))
   ;; align stack to 16-byte boundary