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Fri, 22 Aug 2025 16:56:18 -0700 (PDT) Received: from [192.168.0.226] ([38.34.87.7]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2466889a088sm6937925ad.134.2025.08.22.16.56.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Aug 2025 16:56:18 -0700 (PDT) Message-ID: <0ed1ad1d73d2c4468b3a02b3034b7dfd6e693d66.camel@gmail.com> Subject: Re: [PATCH v4 bpf-next 1/2] bpf: improve the general precision of tnum_mul From: Eduard Zingerman To: Nandakumar Edamana Cc: bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Jakub Sitnicki , Harishankar Vishwanathan Date: Fri, 22 Aug 2025 16:56:12 -0700 In-Reply-To: <116ef3d2-51a5-444c-ad51-126043649226@nandakumar.co.in> References: <20250822170821.2053848-1-nandakumar@nandakumar.co.in> <8834d8df16f050ec9e906a850c894b481dfa022c.camel@gmail.com> <116ef3d2-51a5-444c-ad51-126043649226@nandakumar.co.in> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-1.fc42) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Sat, 2025-08-23 at 05:18 +0530, Nandakumar Edamana wrote: [...] > I personally don't think `best(a*b, b*a)` is ugly. What about > `best(oldprod, newprod)`, where oldprod and newprod are each found > like this, using the old tnum_mul and the new tnum_mul respectively? Hm, given that both are correct if we go for a hybrid approach we can peek known bits from both.