------- Comment #11 from dave at hiauly1 dot hia dot nrc dot ca 2007-02-04
19:55 -------
Subject: Re: FAIL: gfortran.fortran-torture/execute/intrinsic_set_exponent.f90
> > Can you try the following C code?
> >
> > double f(void)
> > {
> > long long t = -1;
> > double t1;
> > __builtin_memcpy(&t1, &t, sizeof(long long));
> > return t;
> > }
>
> Didn't cause a problem. The constant was pushed to memory:
I realized that we should be returning t1 in the above. Also noticed
that the constant that's a problem isn't -1, it's 0xffffffffffff. So
I tweaked the program to see if it made a difference. It didn't change
the generated code for function f.
However, I noticed that the above constant was not output correctly.
It was output as a pair of 32-bit words and the high and low parts were
reversed:
.section .rodata
.align 8
L$C0000:
.word -1
.word 1048575
Don't know why TARGET_ASM_ALIGNED_DI_OP wasn't used here.
# cat yy.c
#include <stdio.h>
double f(void)
{
long long t = 0x000fffffffffffff;
double t1;
__builtin_memcpy(&t1, &t, sizeof(long long));
return t1;
}
int main()
{
union
{
long long ll;
double d;
} u;
u.d = f ();
printf ("ll = 0x%llx\n", u.ll);
return 0;
}
# ../../xgcc -B../../ -O2 -o yy yy.c
# ./yy
ll = 0xffffffff000fffff
# ../../xgcc -B../../ -O0 -o yy yy.c
# ./yy
ll = 0xfffffffffffff
# ../../xgcc -B../../ -v
Reading specs from ../../specs
Target: hppa64-hp-hpux11.00
Configured with: ../gcc/configure --with-gnu-as --with-as=/opt/gnu64/bin/as
--with-ld=/usr/ccs/bin/ld --enable-shared --with-local-prefix=/opt/gnu64
--prefix=/opt/gnu64/gcc/gcc-4.2.0 --host=hppa64-hp-hpux11.00 --disable-nls
--with-gmp=/opt/gnu64/gcc/gcc-4.2.0
Thread model: posix
gcc version 4.2.0 20070123 (prerelease)
Dave
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30634
