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  <jakub@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.

0 files changed, 0 insertions, 0 deletions