From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 22822CCD1AD for ; Sat, 18 Oct 2025 08:52:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 55CBA10E406; Sat, 18 Oct 2025 08:52:02 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="UsZdQ3N3"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4B43810EC3E; Fri, 17 Oct 2025 13:49:06 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 1E5D24B414; Fri, 17 Oct 2025 13:49:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C38DDC16AAE; Fri, 17 Oct 2025 13:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760708946; bh=lNulQj6Pf71EV1G9N3rtKDxmU4z4cUa0H7/cVUNj/bI=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=UsZdQ3N3g1HA9IRop9e0zSxN4roBsUzfuXh2lOF7Ls0u+zs8T+DbQ/PIbdvi3tAUB QmRlkdqorz+9DT4OB5ssGlIv1gvHCWHSThGhzuH1HTR44BAshXSkft+F4USe5TvZ1M r5d8OpcowDu70hyNjetpCQQo/K2qgth9vKzGMuhU= Subject: Patch "minmax: clamp more efficiently by avoiding extra comparison" has been added to the 5.10-stable tree To: David.Laight@ACULAB.COM, Jason@zx2c4.com, adilger.kernel@dilger.ca, agk@redhat.com, airlied@linux.ie, akpm@linux-foundation.org, alexander.deucher@amd.com, alexandre.torgue@st.com, amd-gfx@lists.freedesktop.org, andriy.shevchenko@linux.intel.com, anton.ivanov@cambridgegreys.com, artur.paszkiewicz@intel.com, bp@alien8.de, brian.starkey@arm.com, bvanassche@acm.org, chao@kernel.org, christian.koenig@amd.com, clm@fb.com, coreteam@netfilter.org, daniel@ffwll.ch, dave.hansen@linux.intel.com, davem@davemloft.net, dm-devel@redhat.com, dmitry.torokhov@gmail.com, dri-devel@lists.freedesktop.org, dsterba@suse.com, dushistov@mail.ru, evan.quan@amd.com, farbere@amazon.com, fery@cypress.com, freedreno@lists.freedesktop.org, fw@strlen.de, gregkh@linuxfoundation.org, harry.wentland@amd.com, hdegoede@redhat.com, herve.codina@bootlin.com, hpa@zytor.com, intel-linux-scu@intel.com, jack@suse.com, james.morse@arm.com, james.qian.wang@arm.com, jdelvare@suse.com, jdike@addtoit.com, jejb@linux.ibm.com, jmaloy@redhat.com, joabreu@synopsys.com, josef@toxicpanda.com, kadlec@netfilter.org, kbusch@kernel.org, keescook@chromium.org, kuba@kernel.org, kuznet@ms2.inr.ac.ru, linux-arm-kernel@lists.infradead.org, linux-erofs@lists.ozlabs.org, linux-mm@kvack.org, linux-staging@lists.linux.dev, linux-stm32@st-md-mailman.stormreply.com, linux-um@lists.infradead.org, linux@armlinux.org.uk, linux@rasmusvillemoes.dk, linux@roeck-us.net, liviu.dudau@arm.com, luc.vanoostenryck@gmail.com, luto@kernel.org, maarten.lankhorst@linux.intel.com, malattia@linux.it, martin.petersen@oracle.com, mchehab@kernel.org, mcoquelin.stm32@gmail.com, mgross@linux.intel.com, mihail.atanassov@arm.com, minchan@kernel.org, mingo@redhat.com, mripard@kernel.org, nathan@kernel.org, ndesaulniers@google.com, ngupta@vflare.org, pablo@netfilter.org, peppe.cavallaro@st.com, peterz@infradead.org, pmladek@suse.com, qiuxu.zhuo@intel.com, rajur@chelsio.com, richard@nod.at, robdclark@gmail.com, rostedt@goodmis.org, rric@kernel.org, ruanjinjie@huawei.com, sakari.ailus@linux.intel.com, sashal@kernel.org, sean@poorly.run, serge@freedesktop.org, y.senozhatsky@gmail.com, snitzer@redhat.com, sunpeng.li@amd.com, tglx@linutronix.de, tipc-discussion@lists.sourceforge.net, tony.luck@intel.com, tytso@mit.edu, tzimmermann@suse.de, willy@infradead.org, x86@kernel.org, xiang@kernel.org, ying.xue@windriver.com, yoshfuji@linux-ipv6.org Cc: From: Date: Fri, 17 Oct 2025 15:48:29 +0200 In-Reply-To: <20251017090519.46992-5-farbere@amazon.com> Message-ID: <2025101729-giddiness-scrubbed-89be@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore X-Mailman-Approved-At: Sat, 18 Oct 2025 08:50:54 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" This is a note to let you know that I've just added the patch titled minmax: clamp more efficiently by avoiding extra comparison to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From prvs=378230090=farbere@amazon.com Fri Oct 17 11:07:07 2025 From: Eliav Farber Date: Fri, 17 Oct 2025 09:04:56 +0000 Subject: minmax: clamp more efficiently by avoiding extra comparison To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Message-ID: <20251017090519.46992-5-farbere@amazon.com> From: "Jason A. Donenfeld" [ Upstream commit 2122e2a4efc2cd139474079e11939b6e07adfacd ] Currently the clamp algorithm does: if (val > hi) val = hi; if (val < lo) val = lo; But since hi > lo by definition, this can be made more efficient with: if (val > hi) val = hi; else if (val < lo) val = lo; So fix up the clamp and clamp_t functions to do this, adding the same argument checking as for min and min_t. For simple cases, code generation on x86_64 and aarch64 stay about the same: before: cmp edi, edx mov eax, esi cmova edi, edx cmp edi, esi cmovnb eax, edi ret after: cmp edi, esi mov eax, edx cmovnb esi, edi cmp edi, edx cmovb eax, esi ret before: cmp w0, w2 csel w8, w0, w2, lo cmp w8, w1 csel w0, w8, w1, hi ret after: cmp w0, w1 csel w8, w0, w1, hi cmp w0, w2 csel w0, w8, w2, lo ret On MIPS64, however, code generation improves, by removing arithmetic in the second branch: before: sltu $3,$6,$4 bne $3,$0,.L2 move $2,$6 move $2,$4 .L2: sltu $3,$2,$5 bnel $3,$0,.L7 move $2,$5 .L7: jr $31 nop after: sltu $3,$4,$6 beq $3,$0,.L13 move $2,$6 sltu $3,$4,$5 bne $3,$0,.L12 move $2,$4 .L13: jr $31 nop .L12: jr $31 move $2,$5 For more complex cases with surrounding code, the effects are a bit more complicated. For example, consider this simplified version of timestamp_truncate() from fs/inode.c on x86_64: struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode) { struct super_block *sb = inode->i_sb; unsigned int gran = sb->s_time_gran; t.tv_sec = clamp(t.tv_sec, sb->s_time_min, sb->s_time_max); if (t.tv_sec == sb->s_time_max || t.tv_sec == sb->s_time_min) t.tv_nsec = 0; return t; } before: mov r8, rdx mov rdx, rsi mov rcx, QWORD PTR [r8] mov rax, QWORD PTR [rcx+8] mov rcx, QWORD PTR [rcx+16] cmp rax, rdi mov r8, rcx cmovge rdi, rax cmp rdi, rcx cmovle r8, rdi cmp rax, r8 je .L4 cmp rdi, rcx jge .L4 mov rax, r8 ret .L4: xor edx, edx mov rax, r8 ret after: mov rax, QWORD PTR [rdx] mov rdx, QWORD PTR [rax+8] mov rax, QWORD PTR [rax+16] cmp rax, rdi jg .L6 mov r8, rax xor edx, edx .L2: mov rax, r8 ret .L6: cmp rdx, rdi mov r8, rdi cmovge r8, rdx cmp rax, r8 je .L4 xor eax, eax cmp rdx, rdi cmovl rax, rsi mov rdx, rax mov rax, r8 ret .L4: xor edx, edx jmp .L2 In this case, we actually gain a branch, unfortunately, because the compiler's replacement axioms no longer as cleanly apply. So all and all, this change is a bit of a mixed bag. Link: https://lkml.kernel.org/r/20220926133435.1333846-2-Jason@zx2c4.com Signed-off-by: Jason A. Donenfeld Cc: Andy Shevchenko Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Eliav Farber Signed-off-by: Greg Kroah-Hartman --- include/linux/minmax.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -38,7 +38,7 @@ __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) #define __clamp(val, lo, hi) \ - __cmp(__cmp(val, lo, >), hi, <) + ((val) >= (hi) ? (hi) : ((val) <= (lo) ? (lo) : (val))) #define __clamp_once(val, lo, hi, unique_val, unique_lo, unique_hi) ({ \ typeof(val) unique_val = (val); \ Patches currently in stable-queue which might be from farbere@amazon.com are queue-5.10/minmax-allow-comparisons-of-int-against-unsigned-char-short.patch queue-5.10/minmax-add-a-few-more-min_t-max_t-users.patch queue-5.10/minmax-improve-macro-expansion-and-type-checking.patch queue-5.10/minmax-fix-indentation-of-__cmp_once-and-__clamp_once.patch queue-5.10/minmax.h-simplify-the-variants-of-clamp.patch queue-5.10/minmax-add-in_range-macro.patch queue-5.10/minmax.h-move-all-the-clamp-definitions-after-the-min-max-ones.patch queue-5.10/minmax-allow-min-max-clamp-if-the-arguments-have-the-same-signedness.patch queue-5.10/minmax-don-t-use-max-in-situations-that-want-a-c-constant-expression.patch queue-5.10/minmax.h-remove-some-defines-that-are-only-expanded-once.patch queue-5.10/minmax.h-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch queue-5.10/minmax-simplify-min-max-clamp-implementation.patch queue-5.10/minmax-deduplicate-__unconst_integer_typeof.patch queue-5.10/minmax-simplify-and-clarify-min_t-max_t-implementation.patch queue-5.10/minmax.h-add-whitespace-around-operators-and-after-commas.patch queue-5.10/minmax-sanity-check-constant-bounds-when-clamping.patch queue-5.10/minmax-avoid-overly-complicated-constant-expressions-in-vm-code.patch queue-5.10/minmax-make-generic-min-and-max-macros-available-everywhere.patch queue-5.10/minmax-fix-up-min3-and-max3-too.patch queue-5.10/minmax.h-reduce-the-define-expansion-of-min-max-and-clamp.patch queue-5.10/minmax-fix-header-inclusions.patch queue-5.10/minmax-introduce-min-max-_array.patch queue-5.10/btrfs-remove-duplicated-in_range-macro.patch queue-5.10/overflow-tracing-define-the-is_signed_type-macro-once.patch queue-5.10/minmax-relax-check-to-allow-comparison-between-unsigned-arguments-and-signed-constants.patch queue-5.10/minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch queue-5.10/minmax.h-update-some-comments.patch From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DA561CCD195 for ; 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receiver=lists.ozlabs.org) Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4cp5lR5Qvgz3cdG for ; Sat, 18 Oct 2025 00:49:07 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 1E5D24B414; Fri, 17 Oct 2025 13:49:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C38DDC16AAE; Fri, 17 Oct 2025 13:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760708946; bh=lNulQj6Pf71EV1G9N3rtKDxmU4z4cUa0H7/cVUNj/bI=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=UsZdQ3N3g1HA9IRop9e0zSxN4roBsUzfuXh2lOF7Ls0u+zs8T+DbQ/PIbdvi3tAUB QmRlkdqorz+9DT4OB5ssGlIv1gvHCWHSThGhzuH1HTR44BAshXSkft+F4USe5TvZ1M r5d8OpcowDu70hyNjetpCQQo/K2qgth9vKzGMuhU= Subject: Patch "minmax: clamp more efficiently by avoiding extra comparison" has been added to the 5.10-stable tree To: David.Laight@ACULAB.COM, Jason@zx2c4.com, adilger.kernel@dilger.ca, agk@redhat.com, airlied@linux.ie, akpm@linux-foundation.org, alexander.deucher@amd.com, alexandre.torgue@st.com, amd-gfx@lists.freedesktop.org, andriy.shevchenko@linux.intel.com, anton.ivanov@cambridgegreys.com, artur.paszkiewicz@intel.com, bp@alien8.de, brian.starkey@arm.com, bvanassche@acm.org, chao@kernel.org, christian.koenig@amd.com, clm@fb.com, coreteam@netfilter.org, daniel@ffwll.ch, dave.hansen@linux.intel.com, davem@davemloft.net, dm-devel@redhat.com, dmitry.torokhov@gmail.com, dri-devel@lists.freedesktop.org, dsterba@suse.com, dushistov@mail.ru, evan.quan@amd.com, farbere@amazon.com, fery@cypress.com, freedreno@lists.freedesktop.org, fw@strlen.de, gregkh@linuxfoundation.org, harry.wentland@amd.com, hdegoede@redhat.com, herve.codina@bootlin.com, hpa@zytor.com, intel-linux-scu@intel.com, jack@suse.com, james.morse@arm.com, james.qian.wang@arm.com, jdelvare@suse.com, jdike@addtoit.com, jejb@linux.ibm.com, jmaloy@redhat.com, joabreu@synopsys.com, josef@toxicpanda.com, kadlec@netfilter.org, kbusch@kernel.org, keescook@chromium.org, kuba@kernel.org, kuznet@ms2.inr.ac.ru, linux-arm-kernel@lists.infradead.org, linux-erofs@lists.ozlabs.org, linux-mm@kvack.org, linux-staging@lists.linux.dev, linux-stm32@st-md-mailman.stormreply.com, linux-um@lists.infradead.org, linux@armlinux.org.uk, linux@rasmusvillemoes.dk, linux@roeck-us.net, liviu.dudau@arm.com, luc.vanoostenryck@gmail.com, luto@kernel.org, maarten.lankhorst@linux.intel.com, malattia@linux.it, martin.petersen@oracle.com, mchehab@kernel.org, mcoquelin.stm32@gmail.com, mgross@linux.intel.com, mihail.atanassov@arm.com, minchan@kernel.org, mingo@redhat.com, mripard@kernel.org, nathan@kernel.org, ndesaulniers@google.com, ngupta@vflare.org, pablo@netfilter.org, peppe.cavallaro@st.com, peterz@infradead.org, pmladek@suse.com, qiuxu.zhuo@intel.com, rajur@chelsio.com, richard@nod.at, robdclark@gmail.com, rostedt@goodmis.org, rric@kernel.org, ruanjinjie@huawei.com, sakari.ailus@linux.intel.com, sashal@kernel.org, sean@poorly.run, serge@lists.ozlabs.org, y.senozhatsky@gmail.com, snitzer@redhat.com, sunpeng.li@amd.com, tglx@linutronix.de, tipc-discussion@lists.sourceforge.net, tony.luck@intel.com, tytso@mit.edu, tzimmermann@suse.de, willy@infradead.org, x86@kernel.org, xiang@kernel.org, ying.xue@windriver.com, yoshfuji@linux-ipv6.org Cc: From: Date: Fri, 17 Oct 2025 15:48:29 +0200 In-Reply-To: <20251017090519.46992-5-farbere@amazon.com> Message-ID: <2025101729-giddiness-scrubbed-89be@gregkh> X-Mailing-List: linux-erofs@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore This is a note to let you know that I've just added the patch titled minmax: clamp more efficiently by avoiding extra comparison to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From prvs=378230090=farbere@amazon.com Fri Oct 17 11:07:07 2025 From: Eliav Farber Date: Fri, 17 Oct 2025 09:04:56 +0000 Subject: minmax: clamp more efficiently by avoiding extra comparison To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Message-ID: <20251017090519.46992-5-farbere@amazon.com> From: "Jason A. Donenfeld" [ Upstream commit 2122e2a4efc2cd139474079e11939b6e07adfacd ] Currently the clamp algorithm does: if (val > hi) val = hi; if (val < lo) val = lo; But since hi > lo by definition, this can be made more efficient with: if (val > hi) val = hi; else if (val < lo) val = lo; So fix up the clamp and clamp_t functions to do this, adding the same argument checking as for min and min_t. For simple cases, code generation on x86_64 and aarch64 stay about the same: before: cmp edi, edx mov eax, esi cmova edi, edx cmp edi, esi cmovnb eax, edi ret after: cmp edi, esi mov eax, edx cmovnb esi, edi cmp edi, edx cmovb eax, esi ret before: cmp w0, w2 csel w8, w0, w2, lo cmp w8, w1 csel w0, w8, w1, hi ret after: cmp w0, w1 csel w8, w0, w1, hi cmp w0, w2 csel w0, w8, w2, lo ret On MIPS64, however, code generation improves, by removing arithmetic in the second branch: before: sltu $3,$6,$4 bne $3,$0,.L2 move $2,$6 move $2,$4 .L2: sltu $3,$2,$5 bnel $3,$0,.L7 move $2,$5 .L7: jr $31 nop after: sltu $3,$4,$6 beq $3,$0,.L13 move $2,$6 sltu $3,$4,$5 bne $3,$0,.L12 move $2,$4 .L13: jr $31 nop .L12: jr $31 move $2,$5 For more complex cases with surrounding code, the effects are a bit more complicated. For example, consider this simplified version of timestamp_truncate() from fs/inode.c on x86_64: struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode) { struct super_block *sb = inode->i_sb; unsigned int gran = sb->s_time_gran; t.tv_sec = clamp(t.tv_sec, sb->s_time_min, sb->s_time_max); if (t.tv_sec == sb->s_time_max || t.tv_sec == sb->s_time_min) t.tv_nsec = 0; return t; } before: mov r8, rdx mov rdx, rsi mov rcx, QWORD PTR [r8] mov rax, QWORD PTR [rcx+8] mov rcx, QWORD PTR [rcx+16] cmp rax, rdi mov r8, rcx cmovge rdi, rax cmp rdi, rcx cmovle r8, rdi cmp rax, r8 je .L4 cmp rdi, rcx jge .L4 mov rax, r8 ret .L4: xor edx, edx mov rax, r8 ret after: mov rax, QWORD PTR [rdx] mov rdx, QWORD PTR [rax+8] mov rax, QWORD PTR [rax+16] cmp rax, rdi jg .L6 mov r8, rax xor edx, edx .L2: mov rax, r8 ret .L6: cmp rdx, rdi mov r8, rdi cmovge r8, rdx cmp rax, r8 je .L4 xor eax, eax cmp rdx, rdi cmovl rax, rsi mov rdx, rax mov rax, r8 ret .L4: xor edx, edx jmp .L2 In this case, we actually gain a branch, unfortunately, because the compiler's replacement axioms no longer as cleanly apply. So all and all, this change is a bit of a mixed bag. Link: https://lkml.kernel.org/r/20220926133435.1333846-2-Jason@zx2c4.com Signed-off-by: Jason A. Donenfeld Cc: Andy Shevchenko Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Eliav Farber Signed-off-by: Greg Kroah-Hartman --- include/linux/minmax.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -38,7 +38,7 @@ __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) #define __clamp(val, lo, hi) \ - __cmp(__cmp(val, lo, >), hi, <) + ((val) >= (hi) ? (hi) : ((val) <= (lo) ? (lo) : (val))) #define __clamp_once(val, lo, hi, unique_val, unique_lo, unique_hi) ({ \ typeof(val) unique_val = (val); \ Patches currently in stable-queue which might be from farbere@amazon.com are queue-5.10/minmax-allow-comparisons-of-int-against-unsigned-char-short.patch queue-5.10/minmax-add-a-few-more-min_t-max_t-users.patch queue-5.10/minmax-improve-macro-expansion-and-type-checking.patch queue-5.10/minmax-fix-indentation-of-__cmp_once-and-__clamp_once.patch queue-5.10/minmax.h-simplify-the-variants-of-clamp.patch queue-5.10/minmax-add-in_range-macro.patch queue-5.10/minmax.h-move-all-the-clamp-definitions-after-the-min-max-ones.patch queue-5.10/minmax-allow-min-max-clamp-if-the-arguments-have-the-same-signedness.patch queue-5.10/minmax-don-t-use-max-in-situations-that-want-a-c-constant-expression.patch queue-5.10/minmax.h-remove-some-defines-that-are-only-expanded-once.patch queue-5.10/minmax.h-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch queue-5.10/minmax-simplify-min-max-clamp-implementation.patch queue-5.10/minmax-deduplicate-__unconst_integer_typeof.patch queue-5.10/minmax-simplify-and-clarify-min_t-max_t-implementation.patch queue-5.10/minmax.h-add-whitespace-around-operators-and-after-commas.patch queue-5.10/minmax-sanity-check-constant-bounds-when-clamping.patch queue-5.10/minmax-avoid-overly-complicated-constant-expressions-in-vm-code.patch queue-5.10/minmax-make-generic-min-and-max-macros-available-everywhere.patch queue-5.10/minmax-fix-up-min3-and-max3-too.patch queue-5.10/minmax.h-reduce-the-define-expansion-of-min-max-and-clamp.patch queue-5.10/minmax-fix-header-inclusions.patch queue-5.10/minmax-introduce-min-max-_array.patch queue-5.10/btrfs-remove-duplicated-in_range-macro.patch queue-5.10/overflow-tracing-define-the-is_signed_type-macro-once.patch queue-5.10/minmax-relax-check-to-allow-comparison-between-unsigned-arguments-and-signed-constants.patch queue-5.10/minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch queue-5.10/minmax.h-update-some-comments.patch From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 311D8CCD19F for ; 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spf=pass (imf12.hostedemail.com: domain of gregkh@linuxfoundation.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1760708947; a=rsa-sha256; cv=none; b=xdA1yBdIzhw3vqVaLUwQ1d3CRnxgEnQvT402XmJQf+HPuFjlrAEm6CTrGiweZYnTmk4bKh USbARTbl0pKHFqOJ/2moRkbckiDheOneR1LpUkkBklNtzI6bsqLaOQP1t7Jcx1qBoVznqU wzfIEjE8jrL4O+O/juR2c9kggl5wIDI= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 1C3894B40F; Fri, 17 Oct 2025 13:49:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C38DDC16AAE; Fri, 17 Oct 2025 13:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760708946; bh=lNulQj6Pf71EV1G9N3rtKDxmU4z4cUa0H7/cVUNj/bI=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=UsZdQ3N3g1HA9IRop9e0zSxN4roBsUzfuXh2lOF7Ls0u+zs8T+DbQ/PIbdvi3tAUB QmRlkdqorz+9DT4OB5ssGlIv1gvHCWHSThGhzuH1HTR44BAshXSkft+F4USe5TvZ1M r5d8OpcowDu70hyNjetpCQQo/K2qgth9vKzGMuhU= Subject: Patch "minmax: clamp more efficiently by avoiding extra comparison" has been added to the 5.10-stable tree To: David.Laight@ACULAB.COM, Jason@zx2c4.com, adilger.kernel@dilger.ca, agk@redhat.com, airlied@linux.ie, akpm@linux-foundation.org, alexander.deucher@amd.com, alexandre.torgue@st.com, amd-gfx@lists.freedesktop.org, andriy.shevchenko@linux.intel.com, anton.ivanov@cambridgegreys.com, artur.paszkiewicz@intel.com, bp@alien8.de, brian.starkey@arm.com, bvanassche@acm.org, chao@kernel.org, christian.koenig@amd.com, clm@fb.com, coreteam@netfilter.org, daniel@ffwll.ch, dave.hansen@linux.intel.com, davem@davemloft.net, dm-devel@redhat.com, dmitry.torokhov@gmail.com, dri-devel@lists.freedesktop.org, dsterba@suse.com, dushistov@mail.ru, evan.quan@amd.com, farbere@amazon.com, fery@cypress.com, freedreno@lists.freedesktop.org, fw@strlen.de, gregkh@linuxfoundation.org, harry.wentland@amd.com, hdegoede@redhat.com, herve.codina@bootlin.com, hpa@zytor.com, intel-linux-scu@intel.com, jack@suse.com, james.morse@arm.com, james.qian.wang@arm.com, jdelvare@suse.com, jdike@addtoit.com, jejb@linux.ibm.com, jmaloy@redhat.com, joabreu@synopsys.com, josef@toxicpanda.com, kadlec@netfilter.org, kbusch@kernel.org, keescook@chromium.org, kuba@kernel.org, kuznet@ms2.inr.ac.ru, linux-arm-kernel@lists.infradead.org, linux-erofs@lists.ozlabs.org, linux-mm@kvack.org, linux-staging@lists.linux.dev, linux-stm32@st-md-mailman.stormreply.com, linux-um@lists.infradead.org, linux@armlinux.org.uk, linux@rasmusvillemoes.dk, linux@roeck-us.net, liviu.dudau@arm.com, luc.vanoostenryck@gmail.com, luto@kernel.org, maarten.lankhorst@linux.intel.com, malattia@linux.it, martin.petersen@oracle.com, mchehab@kernel.org, mcoquelin.stm32@gmail.com, mgross@linux.intel.com, mihail.atanassov@arm.com, minchan@kernel.org, mingo@redhat.com, mripard@kernel.org, nathan@kernel.org, ndesaulniers@google.com, ngupta@vflare.org, pablo@netfilter.org, peppe.cavallaro@st.com, peterz@infradead.org, pmladek@suse.com, qiuxu.zhuo@intel.com, rajur@chelsio.com, richard@nod.at, robdclark@gmail.com, rostedt@goodmis.org, rric@kernel.org, ruanjinjie@huawei.com, sakari.ailus@linux.intel.com, sashal@kernel.org, sean@poorly.run, serge@kvack.org, y.senozhatsky@gmail.com, snitzer@redhat.com, sunpeng.li@amd.com, tglx@linutronix.de, tipc-discussion@lists.sourceforge.net, tony.luck@intel.com, tytso@mit.edu, tzimmermann@suse.de, willy@infradead.org, x86@kernel.org, xiang@kernel.org, ying.xue@windriver.com, yoshfuji@linux-ipv6.org Cc: From: Date: Fri, 17 Oct 2025 15:48:29 +0200 In-Reply-To: <20251017090519.46992-5-farbere@amazon.com> Message-ID: <2025101729-giddiness-scrubbed-89be@gregkh> MIME-Version: 1.0 Content-Type: text/plain; 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If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From prvs=378230090=farbere@amazon.com Fri Oct 17 11:07:07 2025 From: Eliav Farber Date: Fri, 17 Oct 2025 09:04:56 +0000 Subject: minmax: clamp more efficiently by avoiding extra comparison To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Message-ID: <20251017090519.46992-5-farbere@amazon.com> From: "Jason A. Donenfeld" [ Upstream commit 2122e2a4efc2cd139474079e11939b6e07adfacd ] Currently the clamp algorithm does: if (val > hi) val = hi; if (val < lo) val = lo; But since hi > lo by definition, this can be made more efficient with: if (val > hi) val = hi; else if (val < lo) val = lo; So fix up the clamp and clamp_t functions to do this, adding the same argument checking as for min and min_t. For simple cases, code generation on x86_64 and aarch64 stay about the same: before: cmp edi, edx mov eax, esi cmova edi, edx cmp edi, esi cmovnb eax, edi ret after: cmp edi, esi mov eax, edx cmovnb esi, edi cmp edi, edx cmovb eax, esi ret before: cmp w0, w2 csel w8, w0, w2, lo cmp w8, w1 csel w0, w8, w1, hi ret after: cmp w0, w1 csel w8, w0, w1, hi cmp w0, w2 csel w0, w8, w2, lo ret On MIPS64, however, code generation improves, by removing arithmetic in the second branch: before: sltu $3,$6,$4 bne $3,$0,.L2 move $2,$6 move $2,$4 .L2: sltu $3,$2,$5 bnel $3,$0,.L7 move $2,$5 .L7: jr $31 nop after: sltu $3,$4,$6 beq $3,$0,.L13 move $2,$6 sltu $3,$4,$5 bne $3,$0,.L12 move $2,$4 .L13: jr $31 nop .L12: jr $31 move $2,$5 For more complex cases with surrounding code, the effects are a bit more complicated. For example, consider this simplified version of timestamp_truncate() from fs/inode.c on x86_64: struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode) { struct super_block *sb = inode->i_sb; unsigned int gran = sb->s_time_gran; t.tv_sec = clamp(t.tv_sec, sb->s_time_min, sb->s_time_max); if (t.tv_sec == sb->s_time_max || t.tv_sec == sb->s_time_min) t.tv_nsec = 0; return t; } before: mov r8, rdx mov rdx, rsi mov rcx, QWORD PTR [r8] mov rax, QWORD PTR [rcx+8] mov rcx, QWORD PTR [rcx+16] cmp rax, rdi mov r8, rcx cmovge rdi, rax cmp rdi, rcx cmovle r8, rdi cmp rax, r8 je .L4 cmp rdi, rcx jge .L4 mov rax, r8 ret .L4: xor edx, edx mov rax, r8 ret after: mov rax, QWORD PTR [rdx] mov rdx, QWORD PTR [rax+8] mov rax, QWORD PTR [rax+16] cmp rax, rdi jg .L6 mov r8, rax xor edx, edx .L2: mov rax, r8 ret .L6: cmp rdx, rdi mov r8, rdi cmovge r8, rdx cmp rax, r8 je .L4 xor eax, eax cmp rdx, rdi cmovl rax, rsi mov rdx, rax mov rax, r8 ret .L4: xor edx, edx jmp .L2 In this case, we actually gain a branch, unfortunately, because the compiler's replacement axioms no longer as cleanly apply. So all and all, this change is a bit of a mixed bag. Link: https://lkml.kernel.org/r/20220926133435.1333846-2-Jason@zx2c4.com Signed-off-by: Jason A. Donenfeld Cc: Andy Shevchenko Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Eliav Farber Signed-off-by: Greg Kroah-Hartman --- include/linux/minmax.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -38,7 +38,7 @@ __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) #define __clamp(val, lo, hi) \ - __cmp(__cmp(val, lo, >), hi, <) + ((val) >= (hi) ? (hi) : ((val) <= (lo) ? (lo) : (val))) #define __clamp_once(val, lo, hi, unique_val, unique_lo, unique_hi) ({ \ typeof(val) unique_val = (val); \ Patches currently in stable-queue which might be from farbere@amazon.com are queue-5.10/minmax-allow-comparisons-of-int-against-unsigned-char-short.patch queue-5.10/minmax-add-a-few-more-min_t-max_t-users.patch queue-5.10/minmax-improve-macro-expansion-and-type-checking.patch queue-5.10/minmax-fix-indentation-of-__cmp_once-and-__clamp_once.patch queue-5.10/minmax.h-simplify-the-variants-of-clamp.patch queue-5.10/minmax-add-in_range-macro.patch queue-5.10/minmax.h-move-all-the-clamp-definitions-after-the-min-max-ones.patch queue-5.10/minmax-allow-min-max-clamp-if-the-arguments-have-the-same-signedness.patch queue-5.10/minmax-don-t-use-max-in-situations-that-want-a-c-constant-expression.patch queue-5.10/minmax.h-remove-some-defines-that-are-only-expanded-once.patch queue-5.10/minmax.h-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch queue-5.10/minmax-simplify-min-max-clamp-implementation.patch queue-5.10/minmax-deduplicate-__unconst_integer_typeof.patch queue-5.10/minmax-simplify-and-clarify-min_t-max_t-implementation.patch queue-5.10/minmax.h-add-whitespace-around-operators-and-after-commas.patch queue-5.10/minmax-sanity-check-constant-bounds-when-clamping.patch queue-5.10/minmax-avoid-overly-complicated-constant-expressions-in-vm-code.patch queue-5.10/minmax-make-generic-min-and-max-macros-available-everywhere.patch queue-5.10/minmax-fix-up-min3-and-max3-too.patch queue-5.10/minmax.h-reduce-the-define-expansion-of-min-max-and-clamp.patch queue-5.10/minmax-fix-header-inclusions.patch queue-5.10/minmax-introduce-min-max-_array.patch queue-5.10/btrfs-remove-duplicated-in_range-macro.patch queue-5.10/overflow-tracing-define-the-is_signed_type-macro-once.patch queue-5.10/minmax-relax-check-to-allow-comparison-between-unsigned-arguments-and-signed-constants.patch queue-5.10/minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch queue-5.10/minmax.h-update-some-comments.patch From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1ED6E2F6906; 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dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="UsZdQ3N3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C38DDC16AAE; Fri, 17 Oct 2025 13:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760708946; bh=lNulQj6Pf71EV1G9N3rtKDxmU4z4cUa0H7/cVUNj/bI=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=UsZdQ3N3g1HA9IRop9e0zSxN4roBsUzfuXh2lOF7Ls0u+zs8T+DbQ/PIbdvi3tAUB QmRlkdqorz+9DT4OB5ssGlIv1gvHCWHSThGhzuH1HTR44BAshXSkft+F4USe5TvZ1M r5d8OpcowDu70hyNjetpCQQo/K2qgth9vKzGMuhU= Subject: Patch "minmax: clamp more efficiently by avoiding extra comparison" has been added to the 5.10-stable tree To: David.Laight@ACULAB.COM,Jason@zx2c4.com,adilger.kernel@dilger.ca,agk@redhat.com,airlied@linux.ie,akpm@linux-foundation.org,alexander.deucher@amd.com,alexandre.torgue@st.com,amd-gfx@lists.freedesktop.org,andriy.shevchenko@linux.intel.com,anton.ivanov@cambridgegreys.com,artur.paszkiewicz@intel.com,bp@alien8.de,brian.starkey@arm.com,bvanassche@acm.org,chao@kernel.org,christian.koenig@amd.com,clm@fb.com,coreteam@netfilter.org,daniel@ffwll.ch,dave.hansen@linux.intel.com,davem@davemloft.net,dm-devel@redhat.com,dmitry.torokhov@gmail.com,dri-devel@lists.freedesktop.org,dsterba@suse.com,dushistov@mail.ru,evan.quan@amd.com,farbere@amazon.com,fery@cypress.com,freedreno@lists.freedesktop.org,fw@strlen.de,gregkh@linuxfoundation.org,harry.wentland@amd.com,hdegoede@redhat.com,herve.codina@bootlin.com,hpa@zytor.com,intel-linux-scu@intel.com,jack@suse.com,james.morse@arm.com,james.qian.wang@arm.com,jdelvare@suse.com,jdike@addtoit.com,jejb@linux.ibm.com,jmaloy@redhat.com,joabreu@synopsys.com,josef@toxicpanda.com,kadlec@netfilter.org,kbusch@kernel.org,keescook@chromium.org,kuba@kernel.org,kuznet@ms2.inr.ac.ru,linux-arm-kernel@lists.infradead.org,linux-erofs@lists.ozlabs.org,linux-mm@kvack.org,linux-staging@lists.linux.dev,linux-stm32@st-md-mailman.stormreply.com,linux-um@lists.infradead.org,linux@armlinux.org.uk,linux@rasmusvillemoes.dk,linux@roeck-us.net,liviu.dudau@arm.com,luc.vanoostenryck@gmail.com,luto@kernel.org,maarten.lankhorst@linux.intel.com,malattia@linux.it,martin.petersen@oracle.com,mchehab@kernel.org,mcoquelin.stm32@gmail.com,mgross@linux.intel.com,mihail.atanassov@arm.com,minchan@kernel.org,mingo@redhat.com,mripard@kernel.org,nathan@kernel.org,ndesaulniers@google.com,ngupta@vflare.org,pablo@netfilter.org,peppe.cavallaro@st.com,peterz@infradead.org,pmladek@suse.com,qiuxu.zhuo@intel.com,rajur@chelsio.com,richard@nod.at,robdclark@gmail.com,rostedt@goodmis.org,rric@kernel.org,ruanjinjie@huawei.com,sakari.ailus@linux.intel.com,sashal@kernel.org,sean@poorly.run,sergey.senozhatsky@gmail.com,snitzer@redhat.com,sunpeng.li@amd.com,tglx@linutronix.de,tipc-discussion@lists.sourceforge.net,tony.luck@intel.com,tytso@mit.edu,tzimmermann@suse.de,willy@infradead.org,x86@kernel.org,xiang@kernel.org,ying.xue@windriver.com,yoshfuji@linux-ipv6.org Cc: From: Date: Fri, 17 Oct 2025 15:48:29 +0200 In-Reply-To: <20251017090519.46992-5-farbere@amazon.com> Message-ID: <2025101729-giddiness-scrubbed-89be@gregkh> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore This is a note to let you know that I've just added the patch titled minmax: clamp more efficiently by avoiding extra comparison to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From prvs=378230090=farbere@amazon.com Fri Oct 17 11:07:07 2025 From: Eliav Farber Date: Fri, 17 Oct 2025 09:04:56 +0000 Subject: minmax: clamp more efficiently by avoiding extra comparison To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Message-ID: <20251017090519.46992-5-farbere@amazon.com> From: "Jason A. Donenfeld" [ Upstream commit 2122e2a4efc2cd139474079e11939b6e07adfacd ] Currently the clamp algorithm does: if (val > hi) val = hi; if (val < lo) val = lo; But since hi > lo by definition, this can be made more efficient with: if (val > hi) val = hi; else if (val < lo) val = lo; So fix up the clamp and clamp_t functions to do this, adding the same argument checking as for min and min_t. For simple cases, code generation on x86_64 and aarch64 stay about the same: before: cmp edi, edx mov eax, esi cmova edi, edx cmp edi, esi cmovnb eax, edi ret after: cmp edi, esi mov eax, edx cmovnb esi, edi cmp edi, edx cmovb eax, esi ret before: cmp w0, w2 csel w8, w0, w2, lo cmp w8, w1 csel w0, w8, w1, hi ret after: cmp w0, w1 csel w8, w0, w1, hi cmp w0, w2 csel w0, w8, w2, lo ret On MIPS64, however, code generation improves, by removing arithmetic in the second branch: before: sltu $3,$6,$4 bne $3,$0,.L2 move $2,$6 move $2,$4 .L2: sltu $3,$2,$5 bnel $3,$0,.L7 move $2,$5 .L7: jr $31 nop after: sltu $3,$4,$6 beq $3,$0,.L13 move $2,$6 sltu $3,$4,$5 bne $3,$0,.L12 move $2,$4 .L13: jr $31 nop .L12: jr $31 move $2,$5 For more complex cases with surrounding code, the effects are a bit more complicated. For example, consider this simplified version of timestamp_truncate() from fs/inode.c on x86_64: struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode) { struct super_block *sb = inode->i_sb; unsigned int gran = sb->s_time_gran; t.tv_sec = clamp(t.tv_sec, sb->s_time_min, sb->s_time_max); if (t.tv_sec == sb->s_time_max || t.tv_sec == sb->s_time_min) t.tv_nsec = 0; return t; } before: mov r8, rdx mov rdx, rsi mov rcx, QWORD PTR [r8] mov rax, QWORD PTR [rcx+8] mov rcx, QWORD PTR [rcx+16] cmp rax, rdi mov r8, rcx cmovge rdi, rax cmp rdi, rcx cmovle r8, rdi cmp rax, r8 je .L4 cmp rdi, rcx jge .L4 mov rax, r8 ret .L4: xor edx, edx mov rax, r8 ret after: mov rax, QWORD PTR [rdx] mov rdx, QWORD PTR [rax+8] mov rax, QWORD PTR [rax+16] cmp rax, rdi jg .L6 mov r8, rax xor edx, edx .L2: mov rax, r8 ret .L6: cmp rdx, rdi mov r8, rdi cmovge r8, rdx cmp rax, r8 je .L4 xor eax, eax cmp rdx, rdi cmovl rax, rsi mov rdx, rax mov rax, r8 ret .L4: xor edx, edx jmp .L2 In this case, we actually gain a branch, unfortunately, because the compiler's replacement axioms no longer as cleanly apply. So all and all, this change is a bit of a mixed bag. Link: https://lkml.kernel.org/r/20220926133435.1333846-2-Jason@zx2c4.com Signed-off-by: Jason A. Donenfeld Cc: Andy Shevchenko Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Eliav Farber Signed-off-by: Greg Kroah-Hartman --- include/linux/minmax.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -38,7 +38,7 @@ __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) #define __clamp(val, lo, hi) \ - __cmp(__cmp(val, lo, >), hi, <) + ((val) >= (hi) ? (hi) : ((val) <= (lo) ? (lo) : (val))) #define __clamp_once(val, lo, hi, unique_val, unique_lo, unique_hi) ({ \ typeof(val) unique_val = (val); \ Patches currently in stable-queue which might be from farbere@amazon.com are queue-5.10/minmax-allow-comparisons-of-int-against-unsigned-char-short.patch queue-5.10/minmax-add-a-few-more-min_t-max_t-users.patch queue-5.10/minmax-improve-macro-expansion-and-type-checking.patch queue-5.10/minmax-fix-indentation-of-__cmp_once-and-__clamp_once.patch queue-5.10/minmax.h-simplify-the-variants-of-clamp.patch queue-5.10/minmax-add-in_range-macro.patch queue-5.10/minmax.h-move-all-the-clamp-definitions-after-the-min-max-ones.patch queue-5.10/minmax-allow-min-max-clamp-if-the-arguments-have-the-same-signedness.patch queue-5.10/minmax-don-t-use-max-in-situations-that-want-a-c-constant-expression.patch queue-5.10/minmax.h-remove-some-defines-that-are-only-expanded-once.patch queue-5.10/minmax.h-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch queue-5.10/minmax-simplify-min-max-clamp-implementation.patch queue-5.10/minmax-deduplicate-__unconst_integer_typeof.patch queue-5.10/minmax-simplify-and-clarify-min_t-max_t-implementation.patch queue-5.10/minmax.h-add-whitespace-around-operators-and-after-commas.patch queue-5.10/minmax-sanity-check-constant-bounds-when-clamping.patch queue-5.10/minmax-avoid-overly-complicated-constant-expressions-in-vm-code.patch queue-5.10/minmax-make-generic-min-and-max-macros-available-everywhere.patch queue-5.10/minmax-fix-up-min3-and-max3-too.patch queue-5.10/minmax.h-reduce-the-define-expansion-of-min-max-and-clamp.patch queue-5.10/minmax-fix-header-inclusions.patch queue-5.10/minmax-introduce-min-max-_array.patch queue-5.10/btrfs-remove-duplicated-in_range-macro.patch queue-5.10/overflow-tracing-define-the-is_signed_type-macro-once.patch queue-5.10/minmax-relax-check-to-allow-comparison-between-unsigned-arguments-and-signed-constants.patch queue-5.10/minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch queue-5.10/minmax.h-update-some-comments.patch