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([140.112.28.118]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3acc492fa54sm4797470a91.13.2026.10.16.09.36.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Oct 2026 09:36:17 -0700 (PDT) From: Tzu-Ching Yang To: Yury Norov Cc: Yury Norov , Rasmus Villemoes , Arnd Bergmann , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] bitops: Share the generic ffs()/fls() binary search via UNROLL() Date: Sat, 17 Oct 2026 00:35:49 +0800 Message-Id: <20261016163549.636471-1-shingekinocore@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: <20261016025634.2690862-1-shingekinocore@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Fri, Oct 16, 2026 at 12:17:00PM -0400, Yury Norov wrote: > Alright, so the basic idea is to hide the exact implementation behind > the macro magic. This is highly unfavorable unless it brings substantial > improvement i.e. in code generation. In kernel we're drifting toward the > exactly opposite direction: getting rid of those macro tricks folded one > into another in favor of the plain human-readable code. Thanks for having a look and for the pointers, understood, and sorry about the length of the description. I'm dropping this one and will follow Arnd's suggestion instead, replacing custom arch helpers with the builtins where that simplifies the code. Thanks, Tzu-Ching