On Tue, Apr 15, 2025 at 02:17:46PM +0200, Martin Jambor wrote:
> Hi,
>
> On Tue, Apr 15 2025, Jakub Jelinek wrote:
> > On Mon, Mar 31, 2025 at 03:34:07PM +0200, Martin Jambor wrote:
> >> This patch just introduces a form of dumping of widest ints that only
> >> have zeros in the lowest 128 bits so that instead of printing
> >> thousands of f's the output looks like:
> >>
> >> Bits: value = 0xffff, mask = all ones folled by
> >> 0xffffffffffffffffffffffffffff0000
> >>
> >> and then makes sure we use the function not only to print bits but
> >> also to print masks where values like these can also occur.
> >
> > Shouldn't that be followed by instead?
>
> Yes, of course.
>
> > And the widest_int checks seems to be quite expensive (especially for
> > large widest_ints), I think for the first one we can just == -1
> > and for the second one wi::arshift (value, 128) == -1 and the zero extension
> > by using wi::zext.
> >
> > Anyway, I wonder if it wouldn't be better to use something shorter,
> > the variant patch uses 0xf..f prefix before the 128-bit hexadecimal
> > number (maybe we could also special case the even more common bits 64+
> > are all ones case). Or it could be 0xf*f prefix. Or printing such
> > numbers as -0x prefixed negative, though that is not a good idea for masks.
>
> I was not sure myself what the best way would be and so proposed the
> simplest variant I could think of. I am fine with anything that does
> not print thousands of f's which could be the case before.
>
> So if you like the second variant more, I and I guess I do as well, by
> all means go ahead and commit it.
Here is perhaps even better one which doesn't print e.g.
0xf..fffffffffffffffffffffffffffff0000
but just
0xf..f0000
(of course, for say mask of
0xf..f0000000000000000000000000000ffff
it prints it like that, doesn't try to shorten the 0 digits.
But if the most significant bits aren't set, it will be just
0xffff
2025-04-15 Jakub Jelinek <ja...@redhat.com>
* ipa-cp.cc (ipcp_print_widest_int): Print values with all ones in
bits 128+ with "0xf..f" prefix instead of "all ones folled by ".
Simplify wide_int check for -1 or all ones above least significant
128 bits.
--- gcc/ipa-cp.cc.jj 2025-04-15 12:22:07.485558525 +0200
+++ gcc/ipa-cp.cc 2025-04-15 14:12:01.327407951 +0200
@@ -313,14 +313,24 @@ ipcp_lattice<valtype>::print (FILE * f,
static void
ipcp_print_widest_int (FILE *f, const widest_int &value)
{
- if (wi::eq_p (wi::bit_not (value), 0))
+ if (value == -1)
fprintf (f, "-1");
- else if (wi::eq_p (wi::bit_not (wi::bit_or (value,
- wi::sub (wi::lshift (1, 128),
- 1))), 0))
+ else if (wi::arshift (value, 128) == -1)
{
- fprintf (f, "all ones folled by ");
- print_hex (wi::bit_and (value, wi::sub (wi::lshift (1, 128), 1)), f);
+ char buf[35], *p = buf + 2;
+ widest_int v = wi::zext (value, 128);
+ size_t len;
+ print_hex (v, buf);
+ len = strlen (p);
+ if (len == 32)
+ {
+ fprintf (f, "0xf..f");
+ while (*p == 'f')
+ ++p;
+ }
+ else
+ fprintf (f, "0xf..f%0*d", (int) (32 - len), 0);
+ fputs (p, f);
}
else
print_hex (value, f);
Jakub
