c/10142: gcc -m64 produces wrong code when passing struct as parameter

[p.van-hoof@qub.ac.uk]

>Number:         10142
>Category:       c
>Synopsis:       gcc -m64 produces wrong code when passing struct as parameter
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Tue Mar 18 23:26:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     Peter van Hoof
>Release:        3.2.2
>Organization:
Queen's University of Belfast
>Environment:
System: SunOS scooby 5.9 Generic_112233-04 sun4u sparc SUNW,Sun-Blade-100
Architecture: sun4

	
host: sparc-sun-solaris2.9
build: sparc-sun-solaris2.9
target: sparc-sun-solaris2.9
configured with: /opt/temp/gcc-3.2.2/configure --prefix=/opt/local --enable-threads
>Description:
In the program below, a struct is passed as a parameter to a routine.
This is clearly done incorrectly, as demonstrated by the print statements.
This bug is triggered by the -m64 flag on the command line, even in
non-optimized mode.

This bug is present in gcc 3.2.2, as well as 3.3 and 3.4.

>How-To-Repeat:

scooby>	gcc h.c
scooby>	a.out 
1.20e+00 25
1.20e+00 25

scooby>	gcc -m64 h.c
scooby>	a.out
1.20e+00 25
1.20e+00 -2147488472

scooby>	cat h.c

typedef struct {
	double m;
	long x;
} mx;

void b(int i1,int i2,int i3,int i4,int i5,int i6,mx m)
{
	printf("%.2e %ld\n",m.m,m.x);
}

int main() {
	mx z={1.2, 25};
	printf( "%.2e %ld\n", z.m, z.x );
	b(1,2,3,4,5,6,z);
	return 0;
}


>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: