Article View: comp.arch
Article #22549Re: RISC Machine Data Structure Word Alignment Problems?
From: Peter da Silva
Date: Thu, 22 Feb 1990 18:04
Date: Thu, 22 Feb 1990 18:04
49 lines
1785 bytes
1785 bytes
> (%): Even the guarantee, that the struct elements are at ascending
> adresses in the order they are declared, IMHO only was given
> to avoid complex (and hard to understand) rules, when and when
> not it would be allowed to rearrange the elements. Readers who
> know other good reasons why this guarantee is given are welcome
> to correct me (hello Chris :-)).
It makes the following two practices reasonably portable:
1:
struct list_header {
struct list_header next, prev;
};
struct object {
struct list_header list;
...
};
struct list_header *my_list == NULL;
struct object my_object;
extern add_list(struct list_header **list, struct list_header *elt);
add_list(&my_list, &my_object);
2:
struct buffer {
int len;
char *next;
char data[1];
};
struct buffer *new_buffer(size)
int size;
{
struct buffer *temp;
temp = (struct buffer *) malloc(sizeof *temp + size);
if(temp) {
temp->len = size;
temp->next = &temp->data[0];
}
return temp;
}
--
_--_|\ Peter da Silva. +1 713 274 5180. <peter@ficc.uu.net>.
/ \
\_.--._/ Xenix Support -- it's not just a job, it's an adventure!
v "Have you hugged your wolf today?" `-_-'
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!ficc!peter From: peter@ficc.uu.net (Peter da Silva) Newsgroups: comp.arch,comp.lang.c Subject: Re: RISC Machine Data Structure Word Alignment Problems? Keywords: risc sun Message-ID: <D.X1XDFxds13@ficc.uu.net> Date: 22 Feb 90 18:04:22 GMT References: <111@melpar.UUCP> <1990Jan21.224826.1699@esegue.segue.boston.ma.us> <S_O1_F6xds13@ficc.uu.net> <1925@l.cc.purdue.edu> <645@mwtech.UUCP> Reply-To: peter@ficc.uu.net (Peter da Silva) Organization: Xenix Support, FICC Lines: 44