On Wed, Mar 12, 2014 at 11:45:03AM +0800, Thomas Preud'homme wrote:
> > From: Jakub Jelinek [mailto:ja...@redhat.com]
> >
> > In theory you could have __CHAR_BIT__ different from 8 and what you care
> > about is that uint32_t has exactly 32 bits, so the check would need to be
> > if (sizeof (uint32_t) * __CHAR_BIT__ != 32)
> > return 0;
>
> I could go with:
>
> In = (0x12 << (__CHAR_BIT__ * 3))
> | (0x34 << (__CHAR_BIT__ * 2))
> | (0x56 << __CHAR_BIT__)
> | 0x78;
>
> and compare with a similarly constructed out so that I could run the test
> whenever sizeof (uint32_t) * __CHAR_BIT__ >= 32, isn't it?
No need to bother, I think we don't have any __CHAR_BIT__ != 8 targets right
now, and after all, the bswap code doesn't bother with it either:
static unsigned int
execute_optimize_bswap (void)
{
basic_block bb;
bool bswap16_p, bswap32_p, bswap64_p;
bool changed = false;
tree bswap16_type = NULL_TREE, bswap32_type = NULL_TREE, bswap64_type =
NULL_TREE;
if (BITS_PER_UNIT != 8)
return 0;
> Thanks for the review. See attachment and below to check the version you
> approved.
Thanks, this is ok.
Jakub
