https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98625
--- Comment #2 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
This looks like a ubsan or optimizer bug. I can't see a -ve shift in the
source:
HOST_WIDE_INT
bytes_in::wi ()
{
HOST_WIDE_INT v = 0;
if (const char *ptr = read (1))
{
v = *ptr & 0xff;
if (v & 0x80)
{
unsigned bytes = (v >> 4) & 0x7;
v &= 0xf;
if (v & 0x8)
v |= -1 ^ 0x7;
if ((ptr = read (++bytes)))
while (bytes--)
v = (v << 8) | (*ptr++ & 0xff);
}
else if (v & 0x40)
v |= -1 ^ 0x3f;
}
return v;
}
only >> 4 and << 8 shifts going on there.
