{"id":2219439,"url":"http://patchwork.ozlabs.org/api/patches/2219439/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260403-cmpxchg-v2-1-23acd2727447@gmail.com/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/","list_archive_url":"https://lore.kernel.org/linuxppc-dev/","list_archive_url_format":"https://lore.kernel.org/linuxppc-dev/{}/","commit_url_format":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}"},"msgid":"<20260403-cmpxchg-v2-1-23acd2727447@gmail.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/20260403-cmpxchg-v2-1-23acd2727447@gmail.com/","date":"2026-04-03T01:19:54","name":"[v2] cmpxchg: allow const-qualified old value in cmpxchg()","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"7a6636db281bed803dcf3ae6c86affc93be617ed","submitter":{"id":15639,"url":"http://patchwork.ozlabs.org/api/people/15639/?format=json","name":"Hangbin Liu","email":"liuhangbin@gmail.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260403-cmpxchg-v2-1-23acd2727447@gmail.com/mbox/","series":[{"id":498574,"url":"http://patchwork.ozlabs.org/api/series/498574/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=498574","date":"2026-04-03T01:19:54","name":"[v2] cmpxchg: allow const-qualified old value in cmpxchg()","version":2,"mbox":"http://patchwork.ozlabs.org/series/498574/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2219439/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2219439/checks/","tags":{},"related":[],"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256\n header.s=20251104 header.b=T09NSeEN;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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charset=\"utf-8\"","Content-Transfer-Encoding":"7bit","Message-Id":"<20260403-cmpxchg-v2-1-23acd2727447@gmail.com>","X-B4-Tracking":"v=1; b=H4sIAAAAAAAC/2XMSwrDIBSF4a2EO65Fb00KHXUfJQPxeaHGoEFSg\n nuvzbTD/3D4Dig2ky3wGA7ItlKhtPTAywA6qMVbRqY3IMeJS45Mx3XXwTN05sbvTkolBfT3mq2\n j/ZRec+9AZUv5c8JV/NZ/owommBwnYVHz0aB++qjofdUpwtxa+wIngfApngAAAA==","X-Change-ID":"20260402-cmpxchg-2fd307f44a41","To":"Richard Henderson ,\n Matt Turner , Magnus Lindholm ,\n Vineet Gupta , Brian Cain ,\n \"James E.J. Bottomley\" ,\n Helge Deller , Madhavan Srinivasan ,\n Michael Ellerman , Nicholas Piggin ,\n \"Christophe Leroy (CS GROUP)\" ,\n Paul Walmsley , Palmer Dabbelt ,\n Albert Ou , Alexandre Ghiti ,\n Yoshinori Sato , Rich Felker ,\n John Paul Adrian Glaubitz ,\n \"David S. Miller\" ,\n Andreas Larsson , Thomas Gleixner ,\n Ingo Molnar , Borislav Petkov ,\n Dave Hansen , x86@kernel.org,\n \"H. Peter Anvin\" , Chris Zankel ,\n Max Filippov ,\n David Laight ","Cc":"linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org,\n linux-snps-arc@lists.infradead.org, linux-hexagon@vger.kernel.org,\n linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,\n linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org,\n sparclinux@vger.kernel.org, Jakub Kicinski ,\n Hangbin Liu ","X-Mailer":"b4 0.14.3","X-Spam-Status":"No, score=-0.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID,\n\tDKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,\n\tSPF_HELO_NONE,SPF_PASS autolearn=disabled version=4.0.1 OzLabs 8","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org"},"content":"The old value passed to cmpxchg() is semantically read-only: it is\nonly loaded into a register as a comparand and is never written back.\nHowever, the macro currently assigns it implicitly to a local variable\nof type __typeof__(*(ptr)), which triggers -Werror=discarded-qualifiers\nwhen old is a const-qualified pointer and ptr points to a non-const type.\n\nFix this by using __auto_type with the conditional expression trick:\n\n __auto_type _o_ = 1 ? (o) : *(ptr);\n\nThe __auto_type deduces the type from the expression, so _o_ naturally\ntakes the const-qualified type when o is const-qualified, avoiding the\ndiscarded-qualifiers warning. The conditional expression forces the\ncompiler to verify that o and *(ptr) have compatible types, preserving\nthe type-safety check that a bare __auto_type _o_ = (o) would lose.\nSince the condition is the constant 1, the compiler optimizes away the\n*(ptr) branch entirely with no runtime cost.\n\nFor macros where ptr is already captured in a local variable (arc's\n_p_, hexagon's __ptr, riscv's __ptr), the captured variable is used\nin the conditional expression to avoid re-evaluating ptr.\n\nThe new value is intentionally left without this treatment: new will\nbe stored into *ptr, so silently accepting a const-qualified new would\nallow callers to store a pointer-to-const into a non-const location\nwithout any compiler warning.\n\nSuggested-by: Jakub Kicinski \nSigned-off-by: Hangbin Liu \n---\nChanges in v2:\n- Use __auto_type as the previous way will loose ptr type checking (David Laight)\n- Link to v1: https://lore.kernel.org/r/20260402-cmpxchg-v1-1-4561e2c05d2c@gmail.com\n---\n arch/alpha/include/asm/cmpxchg.h | 4 ++--\n arch/arc/include/asm/cmpxchg.h | 4 ++--\n arch/hexagon/include/asm/cmpxchg.h | 2 +-\n arch/parisc/include/asm/cmpxchg.h | 2 +-\n arch/powerpc/include/asm/cmpxchg.h | 8 ++++----\n arch/riscv/include/asm/cmpxchg.h | 4 ++--\n arch/sh/include/asm/cmpxchg.h | 2 +-\n arch/sparc/include/asm/cmpxchg_32.h | 2 +-\n arch/sparc/include/asm/cmpxchg_64.h | 2 +-\n arch/x86/include/asm/cmpxchg.h | 2 +-\n arch/xtensa/include/asm/cmpxchg.h | 2 +-\n tools/arch/x86/include/asm/cmpxchg.h | 2 +-\n 12 files changed, 18 insertions(+), 18 deletions(-)\n\n\n---\nbase-commit: f8f5627a8aeab15183eef8930bf75ba88a51622f\nchange-id: 20260402-cmpxchg-2fd307f44a41\n\nBest regards,","diff":"diff --git a/arch/alpha/include/asm/cmpxchg.h b/arch/alpha/include/asm/cmpxchg.h\nindex ae1b96479d0c..e6cb60ca35bf 100644\n--- a/arch/alpha/include/asm/cmpxchg.h\n+++ b/arch/alpha/include/asm/cmpxchg.h\n@@ -234,7 +234,7 @@ ____cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,\n \n #define arch_cmpxchg_local(ptr, o, n)\t\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n-\t__typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t\\\n+\t__auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t\\\n \t__typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t\\\n \t(__typeof__(*(ptr))) ____cmpxchg((ptr), (unsigned long)_o_,\t\\\n \t\t\t\t\t (unsigned long)_n_,\t\t\\\n@@ -265,7 +265,7 @@ ____cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,\n #define arch_cmpxchg(ptr, o, n)\t\t\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n \t__typeof__(*(ptr)) __ret;\t\t\t\t\t\\\n-\t__typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t\\\n+\t__auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t\\\n \t__typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t\\\n \tsmp_mb();\t\t\t\t\t\t\t\\\n \t__ret = (__typeof__(*(ptr))) ____cmpxchg((ptr),\t\t\t\\\ndiff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h\nindex 76f43db0890f..e18609174133 100644\n--- a/arch/arc/include/asm/cmpxchg.h\n+++ b/arch/arc/include/asm/cmpxchg.h\n@@ -42,7 +42,7 @@\n #define arch_cmpxchg_relaxed(ptr, old, new)\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n \t__typeof__(ptr) _p_ = (ptr);\t\t\t\t\t\\\n-\t__typeof__(*(ptr)) _o_ = (old);\t\t\t\t\t\\\n+\t__auto_type _o_ = 1 ? (old) : *(_p_);\t\t\t\t\\\n \t__typeof__(*(ptr)) _n_ = (new);\t\t\t\t\t\\\n \t__typeof__(*(ptr)) _prev_;\t\t\t\t\t\\\n \t\t\t\t\t\t\t\t\t\\\n@@ -64,7 +64,7 @@\n #define arch_cmpxchg(ptr, old, new)\t\t\t\t \\\n ({\t\t\t\t\t\t\t\t\t\\\n \tvolatile __typeof__(ptr) _p_ = (ptr);\t\t\t\t\\\n-\t__typeof__(*(ptr)) _o_ = (old);\t\t\t\t\t\\\n+\t__auto_type _o_ = 1 ? (old) : *(_p_);\t\t\t\t\\\n \t__typeof__(*(ptr)) _n_ = (new);\t\t\t\t\t\\\n \t__typeof__(*(ptr)) _prev_;\t\t\t\t\t\\\n \tunsigned long __flags;\t\t\t\t\t\t\\\ndiff --git a/arch/hexagon/include/asm/cmpxchg.h b/arch/hexagon/include/asm/cmpxchg.h\nindex 9c58fb81f7fd..88986fe04072 100644\n--- a/arch/hexagon/include/asm/cmpxchg.h\n+++ b/arch/hexagon/include/asm/cmpxchg.h\n@@ -54,7 +54,7 @@ __arch_xchg(unsigned long x, volatile void *ptr, int size)\n #define arch_cmpxchg(ptr, old, new)\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\\\n \t__typeof__(ptr) __ptr = (ptr);\t\t\t\t\\\n-\t__typeof__(*(ptr)) __old = (old);\t\t\t\\\n+\t__auto_type __old = 1 ? (old) : *(__ptr);\t\t\\\n \t__typeof__(*(ptr)) __new = (new);\t\t\t\\\n \t__typeof__(*(ptr)) __oldval = (__typeof__(*(ptr))) 0;\t\\\n \t\t\t\t\t\t\t\t\\\ndiff --git a/arch/parisc/include/asm/cmpxchg.h b/arch/parisc/include/asm/cmpxchg.h\nindex bf0a0f1189eb..30748e31aa17 100644\n--- a/arch/parisc/include/asm/cmpxchg.h\n+++ b/arch/parisc/include/asm/cmpxchg.h\n@@ -78,7 +78,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)\n \n #define arch_cmpxchg(ptr, o, n)\t\t\t\t\t\t \\\n ({\t\t\t\t\t\t\t\t\t \\\n-\t__typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t \\\n+\t__auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t \\\n \t__typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t \\\n \t(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,\t \\\n \t\t\t\t (unsigned long)_n_, sizeof(*(ptr))); \\\ndiff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h\nindex dbb50c06f0bf..eaf88b7d0443 100644\n--- a/arch/powerpc/include/asm/cmpxchg.h\n+++ b/arch/powerpc/include/asm/cmpxchg.h\n@@ -698,7 +698,7 @@ __cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new,\n }\n #define arch_cmpxchg(ptr, o, n)\t\t\t\t\t\t \\\n ({\t\t\t\t\t\t\t\t\t \\\n- __typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t \\\n+ __auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t \\\n __typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t \\\n (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,\t\t \\\n \t\t\t\t (unsigned long)_n_, sizeof(*(ptr))); \\\n@@ -707,7 +707,7 @@ __cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new,\n \n #define arch_cmpxchg_local(ptr, o, n)\t\t\t\t\t \\\n ({\t\t\t\t\t\t\t\t\t \\\n- __typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t \\\n+ __auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t \\\n __typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t \\\n (__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_,\t \\\n \t\t\t\t (unsigned long)_n_, sizeof(*(ptr))); \\\n@@ -715,7 +715,7 @@ __cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new,\n \n #define arch_cmpxchg_relaxed(ptr, o, n)\t\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n-\t__typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t\\\n+\t__auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t\\\n \t__typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t\\\n \t(__typeof__(*(ptr))) __cmpxchg_relaxed((ptr),\t\t\t\\\n \t\t\t(unsigned long)_o_, (unsigned long)_n_,\t\t\\\n@@ -724,7 +724,7 @@ __cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new,\n \n #define arch_cmpxchg_acquire(ptr, o, n)\t\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n-\t__typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t\\\n+\t__auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t\\\n \t__typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t\\\n \t(__typeof__(*(ptr))) __cmpxchg_acquire((ptr),\t\t\t\\\n \t\t\t(unsigned long)_o_, (unsigned long)_n_,\t\t\\\ndiff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h\nindex 8712cf9c69dc..30ade671298f 100644\n--- a/arch/riscv/include/asm/cmpxchg.h\n+++ b/arch/riscv/include/asm/cmpxchg.h\n@@ -215,7 +215,7 @@\n \t\t cas_prepend, cas_append)\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n \t__typeof__(ptr) __ptr = (ptr);\t\t\t\t\t\\\n-\t__typeof__(*(__ptr)) __old = (old);\t\t\t\t\\\n+\t__auto_type __old = 1 ? (old) : *(__ptr);\t\t\t\\\n \t__typeof__(*(__ptr)) __new = (new);\t\t\t\t\\\n \t__typeof__(*(__ptr)) __ret;\t\t\t\t\t\\\n \t\t\t\t\t\t\t\t\t\\\n@@ -331,7 +331,7 @@ union __u128_halves {\n \n #define __arch_cmpxchg128(p, o, n, cas_sfx)\t\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\t\\\n-\t__typeof__(*(p)) __o = (o); \\\n+\t__auto_type __o = 1 ? (o) : *(p);\t\t\t\t\t\\\n \tunion __u128_halves __hn = { .full = (n) };\t\t\t\t\\\n \tunion __u128_halves __ho = { .full = (__o) };\t\t\t\t\\\n \tregister unsigned long t1 asm (\"t1\") = __hn.low;\t\t\t\\\ndiff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h\nindex 1e5dc5ccf7bf..6c1bfb367f11 100644\n--- a/arch/sh/include/asm/cmpxchg.h\n+++ b/arch/sh/include/asm/cmpxchg.h\n@@ -68,7 +68,7 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,\n \n #define arch_cmpxchg(ptr,o,n)\t\t\t\t\t\t \\\n ({\t\t\t\t\t\t\t\t\t \\\n- __typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t \\\n+ __auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t \\\n __typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t \\\n (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,\t\t \\\n \t\t\t\t (unsigned long)_n_, sizeof(*(ptr))); \\\ndiff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h\nindex 8c1a3ca34eeb..df40a16dd021 100644\n--- a/arch/sparc/include/asm/cmpxchg_32.h\n+++ b/arch/sparc/include/asm/cmpxchg_32.h\n@@ -55,7 +55,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)\n \n #define arch_cmpxchg(ptr, o, n)\t\t\t\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n-\t__typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t\\\n+\t__auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t\\\n \t__typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t\\\n \t(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,\t\\\n \t\t\t(unsigned long)_n_, sizeof(*(ptr)));\t\t\\\ndiff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h\nindex 3de25262c411..4b540405fcc7 100644\n--- a/arch/sparc/include/asm/cmpxchg_64.h\n+++ b/arch/sparc/include/asm/cmpxchg_64.h\n@@ -170,7 +170,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)\n \n #define arch_cmpxchg(ptr,o,n)\t\t\t\t\t\t \\\n ({\t\t\t\t\t\t\t\t\t \\\n- __typeof__(*(ptr)) _o_ = (o);\t\t\t\t\t \\\n+ __auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t \\\n __typeof__(*(ptr)) _n_ = (n);\t\t\t\t\t \\\n (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,\t\t \\\n \t\t\t\t (unsigned long)_n_, sizeof(*(ptr))); \\\ndiff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h\nindex a88b06f1c35e..e0340579ef69 100644\n--- a/arch/x86/include/asm/cmpxchg.h\n+++ b/arch/x86/include/asm/cmpxchg.h\n@@ -85,7 +85,7 @@ extern void __add_wrong_size(void)\n #define __raw_cmpxchg(ptr, old, new, size, lock)\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n \t__typeof__(*(ptr)) __ret;\t\t\t\t\t\\\n-\t__typeof__(*(ptr)) __old = (old);\t\t\t\t\\\n+\t__auto_type __old = 1 ? (old) : *(ptr);\t\t\t\t\\\n \t__typeof__(*(ptr)) __new = (new);\t\t\t\t\\\n \tswitch (size) {\t\t\t\t\t\t\t\\\n \tcase __X86_CASE_B:\t\t\t\t\t\t\\\ndiff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h\nindex b6db4838b175..057fd24ed125 100644\n--- a/arch/xtensa/include/asm/cmpxchg.h\n+++ b/arch/xtensa/include/asm/cmpxchg.h\n@@ -83,7 +83,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)\n }\n \n #define arch_cmpxchg(ptr,o,n)\t\t\t\t\t\t \\\n-\t({ __typeof__(*(ptr)) _o_ = (o);\t\t\t\t \\\n+\t({ __auto_type _o_ = 1 ? (o) : *(ptr);\t\t\t\t \\\n \t __typeof__(*(ptr)) _n_ = (n);\t\t\t\t \\\n \t (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,\t \\\n \t \t\t\t (unsigned long)_n_, sizeof (*(ptr))); \\\ndiff --git a/tools/arch/x86/include/asm/cmpxchg.h b/tools/arch/x86/include/asm/cmpxchg.h\nindex 0ed9ca2766ad..bbd3960c2218 100644\n--- a/tools/arch/x86/include/asm/cmpxchg.h\n+++ b/tools/arch/x86/include/asm/cmpxchg.h\n@@ -35,7 +35,7 @@ extern void __cmpxchg_wrong_size(void)\n #define __raw_cmpxchg(ptr, old, new, size, lock)\t\t\t\\\n ({\t\t\t\t\t\t\t\t\t\\\n \t__typeof__(*(ptr)) __ret;\t\t\t\t\t\\\n-\t__typeof__(*(ptr)) __old = (old);\t\t\t\t\\\n+\t__auto_type __old = 1 ? (old) : *(ptr);\t\t\t\t\\\n \t__typeof__(*(ptr)) __new = (new);\t\t\t\t\\\n \tswitch (size) {\t\t\t\t\t\t\t\\\n \tcase __X86_CASE_B:\t\t\t\t\t\t\\\n","prefixes":["v2"]}