From: Daniel Berger <Daniel.Berger@...>
Date: 2006-02-17T01:47:36+09:00
Subject: Re: pack("l"), 64 bit question

Yukihiro Matsumoto wrote:
> Hi,
> 
> In message "Re: pack("l"), 64 bit question"
>     on Thu, 16 Feb 2006 17:45:50 +0900, H.Yamamoto <ocean@m2.ccsnet.ne.jp> writes:
> |
> |>This means EXTEND32() macro in pack.c is not working on 64bit Solaris
> |>(and perhaps on other 64bit systems neither).  I have no 64bit machine
> |>at hand.  Could somebody confirm?
> |
> |Me neigher. But we can use HP TestDrive :-)
> |
> |Probably this patch will solve the problem.
> 
> Daniel, could you try this patch on your 64bit box?
> 
> 							matz.
> 
> |--- pack.c	13 Oct 2005 14:30:49 -0000	1.62.2.12
> |+++ pack.c	16 Feb 2006 06:01:07 -0000
> |@@ -347,11 +347,11 @@ num2i32(x)
> |     return 0;			/* not reached */
> | }
> | 
> |-#if SIZEOF_LONG == SIZE32 || SIZEOF_INT == SIZE32
> |+#if SIZEOF_LONG == SIZE32
> | # define EXTEND32(x) 
> | #else
> | /* invariant in modulo 1<<31 */
> |-# define EXTEND32(x) do {if (!natint) {(x) = (I32)(((1<<31)-1-(x))^~(~0<<31));}} while(0)
> |+# define EXTEND32(x) do { if (!natint) {(x) = (((1L<<31)-1-(x))^~(~0L<<31));}} while(0)
> | #endif
> | #if SIZEOF_SHORT == SIZE16
> | # define EXTEND16(x) 
>

Looks good.  The only one I found odd was the [nil] returned by 
"\377\377\377\377".unpack("l_").  Is that expected?  The 32 bit version returns 
[-1].

# 64 bit Ruby

irb(main):001:0> [-1].pack("l")
=> "\377\377\377\377"
irb(main):002:0> "\377\377\377\377".unpack("l")
=> [-1]
irb(main):003:0> "\377\377\377\377".unpack("l_")
=> [nil]
irb(main):004:0> [-1].pack("l_")
=> "\377\377\377\377\377\377\377\377"
irb(main):005:0> "\377\377\377\377\377\377\377\377".unpack("l")
=> [-1]
irb(main):006:0> "\377\377\377\377\377\377\377\377".unpack("l_")
=> [-1]

Thanks,

Dan