[Guile-commits] 02/15: Slim heap-allocated flonums

[Andy Wingo]

wingo pushed a commit to branch master
in repository guile.

commit 41689edfc31dd7e0438d776754d550311a878ce5
Author: Andy Wingo <address@hidden>
Date:   Tue Apr 10 19:54:58 2018 +0200

    Slim heap-allocated flonums
    
    * libguile/numbers.h (struct scm_t_double, struct scm_t_complex): Avoid
      adding an extra padding word on systems with 8-byte pointers.
    * module/system/base/types.scm (cell->object): Update to compute correct
      offset of embedded double.
---
 libguile/numbers.h           | 6 +++++-
 module/system/base/types.scm | 4 ++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/libguile/numbers.h b/libguile/numbers.h
index 83bcc9e..c07082e 100644
--- a/libguile/numbers.h
+++ b/libguile/numbers.h
@@ -4,7 +4,7 @@
 #define SCM_NUMBERS_H
 
 /* Copyright (C) 1995, 1996, 1998, 2000-2006, 2008-2011, 2013, 2014,
- *   2016, 2017 Free Software Foundation, Inc.
+ *   2016-2018 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -172,14 +172,18 @@ typedef long scm_t_inum;
 typedef struct scm_t_double
 {
   SCM type;
+#if SCM_SIZEOF_UINTPTR_T != 8
   SCM pad;
+#endif
   double real;
 } scm_t_double;
 
 typedef struct scm_t_complex
 {
   SCM type;
+#if SCM_SIZEOF_UINTPTR_T != 8
   SCM pad;
+#endif
   double real;
   double imag;
 } scm_t_complex;
diff --git a/module/system/base/types.scm b/module/system/base/types.scm
index c6aaed2..834fa5f 100644
--- a/module/system/base/types.scm
+++ b/module/system/base/types.scm
@@ -1,5 +1,5 @@
 ;;; 'SCM' type tag decoding.
-;;; Copyright (C) 2014, 2015, 2017 Free Software Foundation, Inc.
+;;; Copyright (C) 2014, 2015, 2017, 2018 Free Software Foundation, Inc.
 ;;;
 ;;; This library is free software; you can redistribute it and/or modify it
 ;;; under the terms of the GNU Lesser General Public License as published by
@@ -419,7 +419,7 @@ using BACKEND."
           (((_ & #xffff = %tc16-bignum))
            (inferior-object 'bignum address))
           (((_ & #xffff = %tc16-flonum) pad)
-           (let* ((address (+ address (* 2 %word-size)))
+           (let* ((address (+ address (match %word-size (4 8) (8 8))))
                   (port    (memory-port backend address (sizeof double)))
                   (words   (get-bytevector-n port (sizeof double))))
              (bytevector-ieee-double-ref words 0 (native-endianness))))