Improve the EQUAL transform.

[sbcl.git] / src / assembly / x86 / support.lisp

diff --git a/src/assembly/x86/support.lisp b/src/assembly/x86/support.lisp
index 0d2427e..5c28593 100644 (file)
--- a/src/assembly/x86/support.lisp
+++ b/src/assembly/x86/support.lisp
@@ -9,35 +9,38 @@
 
 (in-package "SB!VM")
 
-(file-comment
- "$Header$")
+;;; The :full-call assembly-routines must use the same full-call
+;;; unknown-values return convention as a normal call, as some
+;;; of the routines will tail-chain to a static-function. The
+;;; routines themselves, however, take all of their arguments
+;;; in registers (this will typically be one or two arguments,
+;;; and is one of the lower bounds on the number of argument-
+;;; passing registers), and thus don't need a call frame, which
+;;; simplifies things for the normal call/return case. When it
+;;; is neccessary for one of the assembly-functions to call a
+;;; static-function it will construct the required call frame.
+;;; Also, none of the assembly-routines return other than one
+;;; value, which again simplifies the return path.
+;;;    -- AB, 2006/Feb/05.
 
-(def-vm-support-routine generate-call-sequence (name style vop)
+(defun generate-call-sequence (name style vop)
   (ecase style
-    (:raw
+    ((:raw :none)
      (values
       `((inst call (make-fixup ',name :assembly-routine)))
       nil))
     (:full-call
      (values
       `((note-this-location ,vop :call-site)
-       (inst call (make-fixup ',name :assembly-routine))
-       (note-this-location ,vop :single-value-return)
-       (move esp-tn ebx-tn))
-      '((:save-p :compute-only))))
-    (:none
-     (values
-      `((inst jmp (make-fixup ',name :assembly-routine)))
-      nil))))
+        (inst call (make-fixup ',name :assembly-routine))
+        (note-this-location ,vop :single-value-return))
+      '((:save-p :compute-only))))))
 
-(def-vm-support-routine generate-return-sequence (style)
+(defun generate-return-sequence (style)
   (ecase style
     (:raw
      `(inst ret))
     (:full-call
-     `(
-       (inst pop eax-tn)
-
-       (inst add eax-tn 2)
-       (inst jmp eax-tn)))
+     `((inst clc)
+       (inst ret)))
     (:none)))