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  14    <H1>[IRCServices Coding] GCC3</H1>
  15     <B>Finny Merrill</B>
  16     <A HREF="mailto:ircservices-coding%40ircservices.za.net?Subject=%5BIRCServices%20Coding%5D%20GCC3&In-Reply-To=3c7b4174.04007%40achurch.org"
  17        TITLE="[IRCServices Coding] GCC3">griever at t2n.org
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  19     <I>Tue Feb 26 00:19:38 PST 2002</I>
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  34 <PRE>On Tue, 26 Feb 2002, Andrew Church wrote:
  35
  36 &gt;<i> &gt;Plus if you did this:
  37 </I>&gt;<i> &gt;
  38 </I>&gt;<i> &gt;struct {
  39 </I>&gt;<i> &gt;  int8_t byte;
  40 </I>&gt;<i> &gt;  /* 8 bits of padding */
  41 </I>&gt;<i> &gt;  int16_t word1, word2;
  42 </I>&gt;<i> &gt;  /* 16 bits of padding! */
  43 </I>&gt;<i> &gt;} bar;
  44 </I>&gt;<i> &gt;
  45 </I>&gt;<i> &gt;it pads the extra 16 bits so it's on a 32 bit boundary.
  46 </I>&gt;<i>
  47 </I>&gt;<i>      Um, no it doesn't:
  48 </I>You're right. Unlike some compilers, GCC doesn't pad types
  49 at the end. It still aligns statics and autos on the 32 bit
  50 boundary, but if you malloced it, there would still be the extra
  51 16 bits.
  52
  53 &gt;<i>
  54 </I>&gt;<i> #include &lt;sys/types.h&gt;
  55 </I>&gt;<i> struct {
  56 </I>&gt;<i>     int8_t byte;
  57 </I>&gt;<i>     int16_t word1, word2;
  58 </I>&gt;<i> } bar;
  59 </I>&gt;<i> main() { printf(&quot;%d\n&quot;, sizeof(bar)); }
  60 </I>&gt;<i>
  61 </I>&gt;<i> &quot;6&quot; is printed: 1 byte + 1 byte of padding + 2*2 bytes.
  62 </I>wierd, I always though structs were multiples of 4 bytes.
  63 &gt;<i>
  64 </I>&gt;<i>      (Incidentally, it looks like you're right on the double/long long
  65 </I>&gt;<i> issue; my apologies.)
  66 </I>&gt;<i>
  67 </I>&gt;<i>   --Andrew Church
  68 </I>&gt;<i>     <A HREF="http://www.ircservices.za.net/mailman/listinfo/ircservices-coding">achurch at achurch.org</A>
  69 </I>&gt;<i>     <A HREF="http://achurch.org/">http://achurch.org/</A>
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  75
  76 </PRE>
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