From 3b8eb4bbd49359d720f3be0b3ebaff5672df4e16 Mon Sep 17 00:00:00 2001
From: Abdulaziz Ghuloum <aghuloum@cs.indiana.edu>
Date: Thu, 3 Jan 2008 04:42:10 -0500
Subject: [PATCH] Ikarus can compile immediates in 64-bit mode. It feels like
 I'm going through my compilers tutorial all over again!

---
 scheme/ikarus.compiler.ss          | 10 +++-
 scheme/last-revision               |  2 +-
 scheme/pass-specify-rep-primops.ss | 85 +++++++++++++++---------------
 scheme/pass-specify-rep.ss         | 29 +++++-----
 scheme/test64.ss                   | 52 ++++++++++++++++++
 src/ikarus-enter.S                 | 65 +++++++++++++++--------
 src/ikarus-exec.c                  |  4 +-
 src/ikarus-fasl.c                  | 14 ++---
 8 files changed, 167 insertions(+), 94 deletions(-)
 create mode 100755 scheme/test64.ss

diff --git a/scheme/ikarus.compiler.ss b/scheme/ikarus.compiler.ss
index dfe05c9..52da73f 100644
--- a/scheme/ikarus.compiler.ss
+++ b/scheme/ikarus.compiler.ss
@@ -1909,7 +1909,8 @@
       [(4) 2]
       [(8) 3]
       [else 
-       (error 'ikarus "wordsize is neither 4 nor 8" wordsize)])) 
+       (error 'ikarus "wordsize is neither 4 nor 8" wordsize)]))
+  (define fx-scale wordsize)
   (define object-alignment (* 2 wordsize))
   (define align-shift (+ wordshift 1))
   (define fx-shift  wordshift)
@@ -2085,6 +2086,13 @@
 (define pcb-collect-key            (* 12 wordsize))
 
 
+(define (fx? x)
+  (let* ([intbits (* wordsize 8)]
+         [fxbits (- intbits fx-shift)])
+    (and (or (fixnum? x) (bignum? x))
+         (<= (- (expt 2 (- fxbits 1)))
+             x
+             (- (expt 2 (- fxbits 1)) 1)))))
 
 
 (module ()
diff --git a/scheme/last-revision b/scheme/last-revision
index 3f15424..fe2568c 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1316
+1317
diff --git a/scheme/pass-specify-rep-primops.ss b/scheme/pass-specify-rep-primops.ss
index 1ffc43d..cc456c8 100644
--- a/scheme/pass-specify-rep-primops.ss
+++ b/scheme/pass-specify-rep-primops.ss
@@ -131,7 +131,7 @@
 (define-primop immediate? safe
   [(P x)
    (make-conditional
-     (tag-test (T x) fixnum-mask fixnum-tag)
+     (tag-test (T x) fx-mask fx-tag)
      (make-constant #t)
      (tag-test (T x) 7 7))]
   [(E x) (nop)])
@@ -151,7 +151,7 @@
 (define-primop pointer-value unsafe
   [(V x) (prm 'logand 
            (prm 'srl (T x) (K 1))
-           (K (* -1 fixnum-scale)))]
+           (K (* -1 fx-scale)))]
   [(P x) (K #t)]
   [(E x) (nop)])
 
@@ -336,7 +336,7 @@
     /section)
 
 (define-primop vector? unsafe
-  [(P x) (sec-tag-test (T x) vector-mask vector-tag fixnum-mask fixnum-tag)]
+  [(P x) (sec-tag-test (T x) vector-mask vector-tag fx-mask fx-tag)]
   [(E x) (nop)])
 
 (define-primop $make-vector unsafe
@@ -349,7 +349,7 @@
                         (K vector-tag))])
           (prm 'mset v 
                (K (- disp-vector-length vector-tag))
-               (K (make-constant (* i fixnum-scale))))
+               (K (make-constant (* i fx-scale))))
           v)]
      [else
       (with-tmp ([alen (align-code (T len) disp-vector-data)])
@@ -566,7 +566,7 @@
 (section ;;; fixnums
 
 (define-primop fixnum? safe
-  [(P x) (tag-test (T x) fixnum-mask fixnum-tag)]
+  [(P x) (tag-test (T x) fx-mask fx-tag)]
   [(E x) (nop)])
 
 
@@ -641,7 +641,7 @@
         (unless (fixnum? b) (interrupt))
         (prm 'int* (T a) (K b))]
        [else
-        (prm 'int* (T a) (prm 'sra (T b) (K fixnum-shift)))])])]
+        (prm 'int* (T a) (prm 'sra (T b) (K fx-shift)))])])]
   [(P x y) (K #t)]
   [(E x y) (nop)])
 
@@ -677,7 +677,7 @@
       (unless (fixnum? i) (interrupt))
       (prm 'sll (T x) (K i))]
      [else 
-      (prm 'sll (T x) (prm 'sra (T i) (K fixnum-shift)))])]
+      (prm 'sll (T x) (prm 'sra (T i) (K fx-shift)))])]
   [(P x i) (K #t)]
   [(E x i) (nop)])
 
@@ -688,23 +688,23 @@
       (unless (fixnum? i) (interrupt))
       (prm 'logand 
            (prm 'sra (T x) (K (if (> i 31) 31 i)))
-           (K (* -1 fixnum-scale)))]
+           (K (* -1 fx-scale)))]
      [else 
-      (with-tmp ([i (prm 'sra (T i) (K fixnum-shift))])
+      (with-tmp ([i (prm 'sra (T i) (K fx-shift))])
         (with-tmp ([i (make-conditional
                         (prm '< i (K 32))
                         i
                         (K 31))])
            (prm 'logand
                 (prm 'sra (T x) i)
-                (K (* -1 fixnum-scale)))))])]
+                (K (* -1 fx-scale)))))])]
   [(P x i) (K #t)]
   [(E x i) (nop)])
 
 (define-primop $fxquotient unsafe
   [(V a b) 
    (with-tmp ([b (T b)]) ;;; FIXME: why is quotient called remainder?
-    (prm 'sll (prm 'remainder (T a) b) (K fixnum-shift)))]
+    (prm 'sll (prm 'remainder (T a) b) (K fx-shift)))]
   [(P a b) (K #t)]
   [(E a b) (nop)])
 
@@ -783,7 +783,7 @@
         (prm 'srl ;;; FIXME: bref
            (prm 'mref (T s)
                 (prm 'int+
-                   (prm 'sra (T i) (K fixnum-shift))
+                   (prm 'sra (T i) (K fx-shift))
                    ;;; ENDIANNESS DEPENDENCY
                    (K (- disp-bignum-data 
                          (- wordsize 1) 
@@ -1004,7 +1004,7 @@
        (prm 'mref (T x)
           (K (- (+ disp-flonum-data 4) vector-tag)))
        (K 20))
-     (K fixnum-shift))])
+     (K fx-shift))])
 
 /section)
 
@@ -1054,7 +1054,7 @@
          (assert-fixnums (car a*) (cdr a*)))]
     [else
      (interrupt-unless 
-       (tag-test (or* (T a) a*) fixnum-mask fixnum-tag))]))
+       (tag-test (or* (T a) a*) fx-mask fx-tag))]))
 
 (define (fixnum-fold-p op a a*)
   (cond
@@ -1309,13 +1309,13 @@
 (define-primop $fixnum->char unsafe
   [(V x) 
    (prm 'logor
-        (prm 'sll (T x) (K (- char-shift fixnum-shift)))
+        (prm 'sll (T x) (K (- char-shift fx-shift)))
         (K char-tag))]
   [(P x) (K #t)]
   [(E x) (nop)])
 
 (define-primop $char->fixnum unsafe
-  [(V x) (prm 'sra (T x) (K (- char-shift fixnum-shift)))]
+  [(V x) (prm 'sra (T x) (K (- char-shift fx-shift)))]
   [(P x) (K #t)]
   [(E x) (nop)])
 
@@ -1403,7 +1403,7 @@
                       (K bytevector-tag))])
          (prm 'mset s
              (K (- disp-bytevector-length bytevector-tag))
-             (K (* n fixnum-scale)))
+             (K (* n fx-scale)))
          (prm 'bset/c s
              (K (+ n (- disp-bytevector-data bytevector-tag)))
              (K 0))
@@ -1411,7 +1411,7 @@
      [else
       (with-tmp ([s (prm 'alloc 
                       (align-code 
-                        (prm 'sra (T n) (K fixnum-shift))
+                        (prm 'sra (T n) (K fx-shift))
                         (+ disp-bytevector-data 1))
                       (K bytevector-tag))])
           (prm 'mset s
@@ -1419,7 +1419,7 @@
             (T n))
           (prm 'bset/c s
                (prm 'int+ 
-                    (prm 'sra (T n) (K fixnum-shift))
+                    (prm 'sra (T n) (K fx-shift))
                     (K (- disp-bytevector-data bytevector-tag)))
                (K 0))
           s)])]
@@ -1447,7 +1447,7 @@
         (prm 'logand
            (prm 'bref (T s)
                 (prm 'int+
-                   (prm 'sra (T i) (K fixnum-shift))
+                   (prm 'sra (T i) (K fx-shift))
                    (K (- disp-bytevector-data bytevector-tag))))
            (K 255))
         (K fx-shift))])]
@@ -1472,7 +1472,7 @@
         (prm 'sll
            (prm 'bref (T s)
                 (prm 'int+
-                   (prm 'sra (T i) (K fixnum-shift))
+                   (prm 'sra (T i) (K fx-shift))
                    (K (- disp-bytevector-data bytevector-tag))))
            (K (- (* wordsize 8) 8)))
         (K (- (* wordsize 8) (+ 8 fx-shift))))])]
@@ -1504,7 +1504,7 @@
          (unless (fixnum? c) (interrupt))
          (prm 'bset/c (T x) 
               (prm 'int+ 
-                   (prm 'sra (T i) (K fixnum-shift))
+                   (prm 'sra (T i) (K fx-shift))
                    (K (- disp-bytevector-data bytevector-tag)))
               (K (cond
                    [(<= -128 c 127) c]
@@ -1513,7 +1513,7 @@
         [else
          (prm 'bset/h (T x)
                (prm 'int+ 
-                    (prm 'sra (T i) (K fixnum-shift))
+                    (prm 'sra (T i) (K fx-shift))
                     (K (- disp-bytevector-data bytevector-tag)))
                (prm 'sll (T c) (K (- 8 fx-shift))))])])])
 
@@ -1522,7 +1522,7 @@
    (with-tmp ([x (prm 'alloc (K (align flonum-size)) (K vector-tag))])
      (prm 'mset x (K (- vector-tag)) (K flonum-tag))
      (prm 'fl:load 
-       (prm 'int+ (T bv) (prm 'sra (T i) (K fixnum-shift)))
+       (prm 'int+ (T bv) (prm 'sra (T i) (K fx-shift)))
        (K (- disp-bytevector-data bytevector-tag)))
      (prm 'fl:store x (K (- disp-flonum-data vector-tag)))
      x)])
@@ -1534,7 +1534,7 @@
 ;   (with-tmp ([x (prm 'alloc (K (align flonum-size)) (K vector-tag))])
 ;     (prm 'mset x (K (- vector-tag)) (K flonum-tag))
 ;     (prm 'fl:load 
-;       (prm 'int+ (T bv) (prm 'sra (T i) (K fixnum-shift)))
+;       (prm 'int+ (T bv) (prm 'sra (T i) (K fx-shift)))
 ;       (K (- disp-bytevector-data bytevector-tag)))
 ;     (prm 'fl:shuffle
 ;       (K (make-object '#vu8(7 6 2 3 4 5 1 0)))
@@ -1549,7 +1549,7 @@
      (with-tmp ([x (prm 'alloc (K (align flonum-size)) (K vector-tag))])
        (prm 'mset x (K (- vector-tag)) (K flonum-tag))
        (with-tmp ([t (prm 'int+ (T bv) 
-                        (prm 'sra (T i) (K fixnum-shift)))])
+                        (prm 'sra (T i) (K fx-shift)))])
          (with-tmp ([x0 (prm 'mref t (K bvoff))])
            (prm 'bswap! x0 x0)
            (prm 'mset x (K (+ floff wordsize)) x0))
@@ -1564,7 +1564,7 @@
    (seq*
      (prm 'fl:load (T x) (K (- disp-flonum-data vector-tag)))
      (prm 'fl:store
-       (prm 'int+ (T bv) (prm 'sra (T i) (K fixnum-shift)))
+       (prm 'int+ (T bv) (prm 'sra (T i) (K fx-shift)))
        (K (- disp-bytevector-data bytevector-tag))))])
 
 
@@ -1573,7 +1573,7 @@
    (with-tmp ([x (prm 'alloc (K (align flonum-size)) (K vector-tag))])
      (prm 'mset x (K (- vector-tag)) (K flonum-tag))
      (prm 'fl:load-single
-       (prm 'int+ (T bv) (prm 'sra (T i) (K fixnum-shift)))
+       (prm 'int+ (T bv) (prm 'sra (T i) (K fx-shift)))
        (K (- disp-bytevector-data bytevector-tag)))
      (prm 'fl:single->double)
      (prm 'fl:store x (K (- disp-flonum-data vector-tag)))
@@ -1585,7 +1585,7 @@
      (prm 'fl:load (T x) (K (- disp-flonum-data vector-tag)))
      (prm 'fl:double->single)
      (prm 'fl:store-single
-       (prm 'int+ (T bv) (prm 'sra (T i) (K fixnum-shift)))
+       (prm 'int+ (T bv) (prm 'sra (T i) (K fx-shift)))
        (K (- disp-bytevector-data bytevector-tag))))])
 
 (define-primop $bytevector-ieee-single-nonnative-ref unsafe
@@ -1594,7 +1594,7 @@
          [floff (- disp-flonum-data vector-tag)])
      (with-tmp ([x (prm 'alloc (K (align flonum-size)) (K vector-tag))])
        (prm 'mset x (K (- vector-tag)) (K flonum-tag))
-       (with-tmp ([t (prm 'int+ (T bv) (prm 'sra (T i) (K fixnum-shift)))])
+       (with-tmp ([t (prm 'int+ (T bv) (prm 'sra (T i) (K fx-shift)))])
          (with-tmp ([x0 (prm 'mref t (K bvoff))])
            (prm 'bswap! x0 x0)
            (prm 'mset x (K floff) x0)))
@@ -1613,7 +1613,7 @@
 ;       (K (make-object '#vu8(7 6 2 3 4 5 1 0)))
 ;       (K (- disp-bytevector-data bytevector-tag)))
 ;     (prm 'fl:store
-;       (prm 'int+ (T bv) (prm 'sra (T i) (K fixnum-shift)))
+;       (prm 'int+ (T bv) (prm 'sra (T i) (K fx-shift)))
 ;       (K (- disp-bytevector-data bytevector-tag))))])
 
 (define-primop $bytevector-ieee-double-nonnative-set! unsafe
@@ -1621,7 +1621,7 @@
    (let ([bvoff (- disp-bytevector-data bytevector-tag)]
          [floff (- disp-flonum-data vector-tag)])
      (with-tmp ([t (prm 'int+ (T bv)
-                      (prm 'sra (T i) (K fixnum-shift)))])
+                      (prm 'sra (T i) (K fx-shift)))])
        (with-tmp ([x0 (prm 'mref (T x) (K floff))])
          (prm 'bswap! x0 x0)
          (prm 'mset t (K (+ bvoff wordsize)) x0))
@@ -1637,7 +1637,7 @@
        (prm 'fl:load (T x) (K floff))
        (prm 'fl:double->single)
        (with-tmp ([t (prm 'int+ (T bv)
-                        (prm 'sra (T i) (K fixnum-shift)))])
+                        (prm 'sra (T i) (K fx-shift)))])
          (prm 'fl:store-single t (K bvoff))
          (with-tmp ([x0 (prm 'mref t (K bvoff))])
            (prm 'bswap! x0 x0)
@@ -1660,7 +1660,7 @@
                       (K string-tag))])
          (prm 'mset s
              (K (- disp-string-length string-tag))
-             (K (* n fixnum-scale)))
+             (K (* n fx-scale)))
          s)]
      [else
       (with-tmp ([s (prm 'alloc 
@@ -1685,7 +1685,7 @@
      [(constant i)
       (unless (fixnum? i) (interrupt))
       (prm 'mref (T s)
-        (K (+ (* i fixnum-scale) 
+        (K (+ (* i fx-scale) 
               (- disp-string-data string-tag))))]
      [else
       (prm 'mref (T s)
@@ -1731,7 +1731,7 @@
      [(constant i) 
       (unless (fixnum? i) (interrupt))
       (prm 'mset (T x) 
-         (K (+ (* i fixnum-scale) (- disp-string-data string-tag)))
+         (K (+ (* i fx-scale) (- disp-string-data string-tag)))
          (T c))]
      [else
       (prm 'mset (T x) 
@@ -1985,18 +1985,18 @@
      (prm 'logand
           (prm 'mref (T x)
                (prm 'int+
-                    (prm 'sra (T i) (K fixnum-shift))
+                    (prm 'sra (T i) (K fx-shift))
                     (K (- disp-code-data vector-tag))))
           (K 255))
-     (K fixnum-shift))])
+     (K fx-shift))])
 
 (define-primop $code-set! unsafe
   [(E x i v)
    (prm 'bset/h (T x)
         (prm 'int+ 
-             (prm 'sra (T i) (K fixnum-shift))
+             (prm 'sra (T i) (K fx-shift))
              (K (- disp-code-data vector-tag)))
-        (prm 'sll (T v) (K (- 8 fixnum-shift))))])
+        (prm 'sll (T v) (K (- 8 fx-shift))))])
 
 (define-primop $set-code-annotation! unsafe
   [(E x v) (mem-assign v (T x) (- disp-code-annotation vector-tag))])
@@ -2010,9 +2010,10 @@
 
 (define-primop $data->transcoder unsafe
   [(V x) (prm 'logor
-              (prm 'sll (T x) (K (- transcoder-payload-shift fixnum-shift)))
+              (prm 'sll (T x) (K (- transcoder-payload-shift
+                                    fx-shift)))
               (K transcoder-tag))])
 (define-primop $transcoder->data unsafe
-  [(V x) (prm 'sra (T x) (K (- transcoder-payload-shift fixnum-shift)))])
+  [(V x) (prm 'sra (T x) (K (- transcoder-payload-shift fx-shift)))])
 /section)
 
diff --git a/scheme/pass-specify-rep.ss b/scheme/pass-specify-rep.ss
index 8e91a57..421f0c8 100644
--- a/scheme/pass-specify-rep.ss
+++ b/scheme/pass-specify-rep.ss
@@ -20,17 +20,17 @@
 ;
 ;#!eof
 
-(define-syntax export-all-module
-  (syntax-rules (define)
-    [(_ M (define name* v*) ...)
-     (module M (name* ...)
-       (define name* v*) ...)]))
-
-(export-all-module object-representation
-  (define fixnum-scale 4)
-  (define fixnum-shift 2)
-  (define fixnum-tag 0)
-  (define fixnum-mask 3))
+;(define-syntax export-all-module
+;  (syntax-rules (define)
+;    [(_ M (define name* v*) ...)
+;     (module M (name* ...)
+;       (define name* v*) ...)]))
+;
+;(export-all-module object-representation
+;  (define fixnum-scale 4)
+;  (define fixnum-shift 2)
+;  (define fixnum-tag 0)
+;  (define fixnum-mask 3))
 
 (module primops (primop? get-primop set-primop!)
   (define cookie (gensym))
@@ -44,7 +44,7 @@
   )
 
 (module (specify-representation)
-  (import object-representation)
+  ;(import object-representation)
   (import primops)
   (define-struct PH
     (interruptable? p-handler p-handled? v-handler v-handled? e-handler e-handled?))
@@ -325,10 +325,11 @@
            (build-closures clhs* crhs*
              (build-setters clhs* crhs* body)))])))
 
+
   (define (constant-rep x)
     (let ([c (constant-value x)])
       (cond
-        [(fixnum? c) (make-constant (* c fixnum-scale))]
+        [(fx? c) (make-constant (* c fx-scale))]
         [(boolean? c) (make-constant (if c bool-t bool-f))]
         [(eq? c (void)) (make-constant void-object)]
         [(bwp-object? c) (make-constant bwp-object)]
@@ -461,7 +462,7 @@
   (define (interrupt-when x)
     (make-conditional x (interrupt) (prm 'nop))) 
   (define (interrupt-unless-fixnum x)
-    (interrupt-unless (tag-test x fixnum-mask fixnum-tag)))
+    (interrupt-unless (tag-test x fx-mask fx-tag)))
 
 
   (define (T x)
diff --git a/scheme/test64.ss b/scheme/test64.ss
new file mode 100755
index 0000000..1102808
--- /dev/null
+++ b/scheme/test64.ss
@@ -0,0 +1,52 @@
+#!/usr/bin/env ikarus --r6rs-script
+;;; Ikarus Scheme -- A compiler for R6RS Scheme.
+;;; Copyright (C) 2006,2007  Abdulaziz Ghuloum
+;;; 
+;;; This program is free software: you can redistribute it and/or modify
+;;; it under the terms of the GNU General Public License version 3 as
+;;; published by the Free Software Foundation.
+;;; 
+;;; This program is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;; General Public License for more details.
+;;; 
+;;; You should have received a copy of the GNU General Public License
+;;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; vim:syntax=scheme
+(import 
+  (ikarus compiler)
+  (except (ikarus) assembler-output))
+
+(define (compile1 x)
+  (printf "Compiling ~s\n" x)
+  (let ([p (open-file-output-port "test64.boot" (file-options no-fail))])
+    (parameterize ([assembler-output #t])
+      (compile-core-expr-to-port x p))
+    (close-output-port p)))
+
+(define (compile-and-run x) 
+  (compile1 x)
+  (let ([rs (system "../src/ikarus -b test64.boot > test64.out")])
+    (unless (= rs 0) (error 'run1 "died"))
+    (with-input-from-file "test64.out" read)))
+
+(define (compile-test-and-run expr expected)
+  (let ([val (compile-and-run expr)])
+    (unless (equal? val expected) 
+      (error 'compile-test-and-run "failed:got:expected" val expected))))
+
+(define all-tests
+  '([(quote 42)   42]
+    [(quote #f)   #f]
+    [(quote ())  ()]))
+
+(for-each
+  (lambda (x)
+     (compile-test-and-run (car x) (cadr x)))
+  all-tests)
+
+
+(printf "Happy Happy Joy Joy\n")
+
diff --git a/src/ikarus-enter.S b/src/ikarus-enter.S
index 3afda16..1ae6293 100644
--- a/src/ikarus-enter.S
+++ b/src/ikarus-enter.S
@@ -32,18 +32,31 @@
 .align 8
 ik_asm_enter:
 _ik_asm_enter:
-  # ignored value is the third arg 12(%esp)
-  # code is the second arg  8(%esp)
-  # pcb is the first arg    4(%esp)
-  # return point is at      0(%esp)
-  movl %esi, -4(%esp)    #  preserve
-  movl %ebp, -8(%esp)    #  preserve
-  movl 4(%esp), %esi   
-  movl 0(%esi), %ebp     # allocation pointer is at 0(pcb)
-  movl %esp, %eax
-  subl $16, %esp         # 24 for alignment
-  movl %esp, 24(%esi)    # save esp in pcb->system_stack
-  movl 8(%esi), %esp     # load scheme stack from pcb->frame_pinter
+# c parameters come in registers:
+#     %rdi, %rsi, %rdx, %rcx, %r8 and %r9
+# return value registers are %rax and %rdi
+# callee-save registers:
+#     %rbp, %rbx, %r12, r13, r14, %r15 are callee-save 
+
+
+  # First, save all callee-save registers
+  mov %rbp,  -8(%rsp)      # preserve
+  mov %rbx,  -16(%rsp)     # preserve
+  mov %r12,  -24(%rsp)     # preserve
+  mov %r13,  -32(%rsp)     # preserve
+  mov %r14,  -40(%rsp)     # preserve
+  mov %r15,  -48(%rsp)     # preserve
+
+  # code is the second arg, or  %rsi
+  # pcb is the first arg, or    %rdi
+  # return point is at       0(%rsp)
+
+  mov %rsi, %rax     # move code pointer to %rax
+  mov %rdi, %rsi     # move pcb into pcb-register (%rsi)
+  mov 0(%rsi), %rbp  # allocation pointer is at 0(pcb)
+  sub $64, %rsp         # 64 for alignment
+  mov %rsp, 48(%rsi)    # save esp in pcb->system_stack
+  mov 16(%rsi), %rsp    # load scheme stack from pcb->frame_pinter
   jmp L_call
   .byte 0
   .byte 0
@@ -59,21 +72,27 @@ L_multivalue_label: # FIXME
   .byte 0
   .byte 0
 L_call:
-  call *8(%eax)         # goooooooo
+  call *%rax         # goooooooo
   # now we're back
 ik_underflow_handler:
-  movl %eax, -8(%esp)   # store the return value
-  movl $-4, %eax        # set rvcount = 1
+  mov %rax, -16(%rsp)   # store the return value
+  mov $-8, %rax         # set rvcount = 1
 L_do_underflow:
-  movl %esp, 8(%esi)    # store scheme stack in pcb->frame_pointer
-  movl %ebp, 0(%esi)    # store allocation pointer
-  movl 24(%esi), %esp   # restore system stack
-  addl $16, %esp        # 24 for alignment (>= 16)
-  movl -4(%esp), %esi   # restore callee-save registers
-  movl -8(%esp), %ebp   #
-  ret                   # back to C, which handled the underflow
+  mov %rsp, 16(%rsi)    # store scheme stack in pcb->frame_pointer
+  mov %rbp, 0(%rsi)     # store allocation pointer
+  mov 48(%rsi), %rsp    # restore system stack
+  add $64, %rsp         # 64 for alignment
+
+  # restore callee-save registers
+  mov -8(%rsp) ,  %rbp     # restore
+  mov -16(%rsp),  %rbx     # restore
+  mov -24(%rsp),  %r12     # restore
+  mov -32(%rsp),  %r13     # restore
+  mov -40(%rsp),  %r14     # restore
+  mov -48(%rsp),  %r15     # restore
+  ret      # back to C, which handled the underflow
 L_multivalue_underflow:
-  addl $4, %esp
+  add $8, %rsp
   jmp L_do_underflow
 
 
diff --git a/src/ikarus-exec.c b/src/ikarus-exec.c
index a07ad07..744f5e4 100644
--- a/src/ikarus-exec.c
+++ b/src/ikarus-exec.c
@@ -64,8 +64,8 @@ ikptr ik_exec_code(ikpcb* pcb, ikptr code_ptr){
     argc = ik_asm_reenter(pcb, new_fbase, argc);
     next_k =  pcb->next_k;
   }
-  return ref(pcb->frame_base, -2*wordsize);
-  return argc;
+  ikptr rv = ref(pcb->frame_base, -2*wordsize);
+  return rv;
 }
 
 
diff --git a/src/ikarus-fasl.c b/src/ikarus-fasl.c
index 68ca2b6..6532f6a 100644
--- a/src/ikarus-fasl.c
+++ b/src/ikarus-fasl.c
@@ -110,16 +110,12 @@ void ik_fasl_load(ikpcb* pcb, char* fasl_file){
       }
       close(fd);
     }
-    ikptr val = void_object;
     if(wordsize == 4){
       ik_exec_code(pcb, v);
     } else {
-      fprintf(stderr, "NOT EXECING YET\n");
-    }
-    if(val != void_object){
-      /* this is from revision 1 
-         and is no longer needed 
-         and should be removed */
+      fprintf(stderr, ";;; EXECING ...\n");
+      ikptr val = ik_exec_code(pcb, v);
+      fprintf(stderr, ";;; RETURNED ...\n");
       ik_print(val);
     }
   }
@@ -127,10 +123,6 @@ void ik_fasl_load(ikpcb* pcb, char* fasl_file){
     fprintf(stderr, "fasl-read did not reach eof!\n");
     exit(-10);
   }
-  if(wordsize == 8){
-    fprintf(stderr, "DONE READING FASL, EXITING ...\n");
-    exit(-1);
-  }
 }
 
 static ikptr