>> (x & -1) == x
>>(x | -1) == -1
>>(x ^ -1) == ~x
Looks reasonable to me.
Do you mean modify the code as follows ?
if (integer_zerop (arg1) || integer_zerop (arg2)) || integer_onep (arg1)
|| integer_onep(arg2))
step_ok_p = (code == BIT_AND_EXPR || code == BIT_IOR_EXPR
|| code == BIT_XOR_EXPR);
[email protected]
From: Jakub Jelinek
Date: 2023-12-19 17:45
To: [email protected]
CC: rguenther; Robin Dapp; gcc-patches; pan2.li; richard.sandiford; Richard
Biener; pinskia
Subject: Re: Re: [PATCH] fold-const: Handle AND, IOR, XOR with stepped vectors
[PR112971].
On Tue, Dec 19, 2023 at 05:35:14PM +0800, [email protected] wrote:
> I wonder whether we can simplify the codes as follows :?
> if (integer_zerop (arg1) || integer_zerop (arg2))
> step_ok_p = (code == BIT_AND_EXPR || code == BIT_IOR_EXPR
> || code == BIT_XOR_EXPR);
What about integer_all_onesp (arg1) || integer_all_onesp (arg2) ?
(x & -1) == x
(x | -1) == -1
(x ^ -1) == ~x
even for the VL vectors, no?
Jakub
