https://gcc.gnu.org/g:bf115fd45772de34cd24de02c41fdb175897f057
commit r15-9482-gbf115fd45772de34cd24de02c41fdb175897f057
Author: Jakub Jelinek <ja...@redhat.com>
Date: Tue Apr 15 14:56:30 2025 +0200
ipa-cp: Fix up ipcp_print_widest_int
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?
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.
This version 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.
Diff:
---
gcc/ipa-cp.cc | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
index 26b1496f29bb..379fbc5dd637 100644
--- a/gcc/ipa-cp.cc
+++ b/gcc/ipa-cp.cc
@@ -313,14 +313,24 @@ ipcp_lattice<valtype>::print (FILE * f, bool
dump_sources, bool dump_benefits)
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))
- {
- fprintf (f, "all ones folled by ");
- print_hex (wi::bit_and (value, wi::sub (wi::lshift (1, 128), 1)), f);
+ else if (wi::arshift (value, 128) == -1)
+ {
+ 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);
