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Peter Anvin" , Charlie Jenkins , Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org Subject: Re: [PATCH v2 5/6] Eliminate CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT Message-ID: Mail-Followup-To: Nicolas Schier , Nathan Chancellor , Julian Braha , Nick Desaulniers , Bill Wendling , Justin Stitt , Arnd Bergmann , Kees Cook , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, llvm@lists.linux.dev, Linus Torvalds , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Charlie Jenkins , Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org References: <20261111-kconfig-toolchain-updates-v2-0-b2d9415c1757@kernel.org> <20261111-kconfig-toolchain-updates-v2-5-b2d9415c1757@kernel.org> X-Mailing-List: llvm@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261111-kconfig-toolchain-updates-v2-5-b2d9415c1757@kernel.org> On Wed, Nov 11, 2026 at 05:52:07PM -0700, Nathan Chancellor wrote: > Commit 1aa0e8b144b6 ("Kconfig: Add option for asm goto w/ tied outputs > to workaround clang-13 bug") added CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT to > avoid a bug in clang's asm goto with outputs support when a tied output > was used. The fix in clang was to match GCC's documented behavior. > > Now that the minimum supported version of clang has long been bumped > past the version where the fix landed (clang-14), any compiler that > satisfies the dependencies of CONFIG_CC_HAS_ASM_GOTO_OUTPUT will support > tied outputs properly. Eliminate CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT in > favor of just checking for CONFIG_CC_HAS_ASM_GOTO_OUTPUT directly. > > Signed-off-by: Nathan Chancellor > --- [...] > diff --git a/scripts/Kconfig.toolchain b/scripts/Kconfig.toolchain > index 6520a06a9103..9454ef5294d5 100644 > --- a/scripts/Kconfig.toolchain > +++ b/scripts/Kconfig.toolchain > @@ -120,11 +120,6 @@ config CC_HAS_ASM_GOTO_OUTPUT > depends on !GCC_ASM_GOTO_OUTPUT_BROKEN > depends on $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null) > > -config CC_HAS_ASM_GOTO_TIED_OUTPUT > - depends on CC_HAS_ASM_GOTO_OUTPUT > - # Detect buggy gcc and clang, fixed in gcc-11 clang-14. > - def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null) The comments reads as if gcc 8 to 10 are affected. Is the comment somehow misleading, or should we still keep this until gcc-10 is the minimum gcc version? -- Nicolas