Path: utzoo!telly!ddsw1!lll-winken!uunet!tut.cis.ohio-state.edu!MOOSE.CITA.UTORONTO.CA!trq
From: trq@MOOSE.CITA.UTORONTO.CA (Tom Quinn)
Newsgroups: gnu.gcc.bug
Subject: bug in sparc gcc 1.31
Message-ID: <8812021502.AA29471@moose.cita.utoronto.ca>
Date: 2 Dec 88 15:02:05 GMT
Sender: daemon@tut.cis.ohio-state.edu
Distribution: gnu
Organization: GNUs Not Usenet
Lines: 77

Gcc compiles the following code into assembly that will cause a data
misalignment signal.  This gcc version 1.31 on a sun4/110 running
SunOS 4.0.

Tom Quinn                 Canadian Institute for Theoretical Astrophysics
trq@moose.cita.utoronto.ca
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The compile:
gcc -S -g -v  -sun4 -c  Convert.c
gcc version 1.31
 /usr/local/lib/gcc-cpp -v -undef -D__GNU__ -D__GNUC__ -Dsparc -Dsun -Dunix Convert.c /tmp/cca17790.cpp
GNU CPP version 1.31
 /usr/local/lib/gcc-cc1 /tmp/cca17790.cpp -quiet -dumpbase Convert.c -g -version -o Convert.s
GNU C version 1.31 (sparc) compiled by GNU C version 1.31.

The offending assembler:
.stabn 68,0,43,LM11
LM11:
	ld [%fp+84],%o0
	ldd [%l1+28],%l4	<<This instruction will fault
	std %l4,[%o0]		<<This one will too

The code:
typedef	char *	caddr_t;
typedef struct {
    unsigned int    size;
    caddr_t	    addr;
} XrmValue, *XrmValuePtr;
typedef unsigned int   Cardinal;
typedef (*XtConverter)();
typedef struct _CacheRec *CachePtr;
typedef struct _CacheRec {
    CachePtr	next;
    int		hash;
    XtConverter converter;
    XrmValue	*args;
    Cardinal	num_args;
    XrmValue	from;
    XrmValue	to;
} CacheRec;
typedef CachePtr CacheHashTable[256 ];
static CacheHashTable	cacheHashTable;
void XtDirectConvert(converter, args, num_args, from, to)
    XtConverter     converter;
    XrmValuePtr     args;
    Cardinal	    num_args;
    register XrmValuePtr from;
    XrmValuePtr     to;
{
    register CachePtr   p;
    register int	hash;
    register Cardinal   i;
    hash = ((int)(converter) >> 2) + from->size + *((char *) from->addr);
    if (from->size > 1) hash += ((char *) from->addr)[1];
    for (p = cacheHashTable[hash & 255 ]; p != 0 ; p = p->next) {
	if ((p->hash == hash)
	 && (p->converter == converter)
	 && (p->from.size == from->size)
         && (p->num_args == num_args)) {
	    for (i = 0; i < num_args; i++) {
		if (   p->args[i].size != args[i].size ) {
		    break;
		}
	    }
	    if (i == num_args) {	 
		(*to) = p->to;
		return;
	    }
	}
    }
    (*to).size = 0;
    (*to).addr = 0 ;
    (*converter)(args, &num_args, from, to);
    CacheEnter(converter, args, num_args, from, to, hash);
}