From: Richard Sandiford <richard.sandiford@arm.com>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Biener <rguenther@suse.de>, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] wide-int: Allow up to 16320 bits wide_int and change widest_int precision to 32640 bits [PR102989]
Date: Thu, 12 Oct 2023 11:54:14 +0100 [thread overview]
Message-ID: <mptpm1kaz6x.fsf@arm.com> (raw)
In-Reply-To: <ZSbRqzsy4z0zH0O9@tucnak> (Jakub Jelinek's message of "Wed, 11 Oct 2023 18:47:39 +0200")
Jakub Jelinek <jakub@redhat.com> writes:
> @@ -2036,11 +2075,20 @@ wi::lrshift_large (HOST_WIDE_INT *val, c
> unsigned int xlen, unsigned int xprecision,
> unsigned int precision, unsigned int shift)
> {
> - unsigned int len = rshift_large_common (val, xval, xlen, xprecision, shift);
> + /* Work out how many blocks are needed to store the significant bits
> + (excluding the upper zeros or signs). */
> + unsigned int blocks_needed = BLOCKS_NEEDED (xprecision - shift);
> + unsigned int len = blocks_needed;
> + if (UNLIKELY (len > WIDE_INT_MAX_INL_ELTS)
> + && len > xlen
> + && xval[xlen - 1] >= 0)
> + len = xlen;
I think here too it would be worth dropping the:
UNLIKELY (len > WIDE_INT_MAX_INL_ELTS)
part of the condition, since presumably the change should be safe
regardless of that.
> +
> + rshift_large_common (val, xval, xlen, shift, len);
>
> /* The value we just created has precision XPRECISION - SHIFT.
> Zero-extend it to wider precisions. */
> - if (precision > xprecision - shift)
> + if (precision > xprecision - shift && len == blocks_needed)
> {
> unsigned int small_prec = (xprecision - shift) % HOST_BITS_PER_WIDE_INT;
> if (small_prec)
> @@ -2063,11 +2111,18 @@ wi::arshift_large (HOST_WIDE_INT *val, c
> unsigned int xlen, unsigned int xprecision,
> unsigned int precision, unsigned int shift)
> {
> - unsigned int len = rshift_large_common (val, xval, xlen, xprecision, shift);
> + /* Work out how many blocks are needed to store the significant bits
> + (excluding the upper zeros or signs). */
> + unsigned int blocks_needed = BLOCKS_NEEDED (xprecision - shift);
> + unsigned int len = blocks_needed;
> + if (UNLIKELY (len > WIDE_INT_MAX_INL_ELTS) && len > xlen)
> + len = xlen;
> +
Same here.
OK for thw wide-int parts with those changes.
Thanks,
Richard
next prev parent reply other threads:[~2023-10-12 10:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-11 16:47 Jakub Jelinek
2023-10-12 10:54 ` Richard Sandiford [this message]
2023-10-12 11:10 ` Jakub Jelinek
2023-10-12 11:34 ` Richard Sandiford
2023-10-12 11:10 ` Richard Biener
-- strict thread matches above, loose matches on Subject: below --
2023-10-09 10:55 Jakub Jelinek
2023-10-09 12:54 ` Richard Sandiford
2023-10-09 13:44 ` Jakub Jelinek
2023-10-09 18:28 ` Jakub Jelinek
2023-10-10 17:41 ` Richard Sandiford
2023-10-10 18:13 ` Jakub Jelinek
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