From 28f506566ddf2b2a0513b7b140bb91c977871a98 Mon Sep 17 00:00:00 2001 From: LLVM Packaging Team Date: Fri, 2 Jun 2017 13:14:18 +0000 Subject: [PATCH] atomic_library_1 =================================================================== Gbp-Pq: Name atomic_library_1.diff --- clang/lib/Basic/Targets.cpp | 14 ++++++++++++++ clang/test/CodeGen/linux-arm-atomic.c | 10 ++++++++++ 2 files changed, 24 insertions(+) diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp index be5d4ad8..845a333c 100644 --- a/clang/lib/Basic/Targets.cpp +++ b/clang/lib/Basic/Targets.cpp @@ -4282,6 +4282,20 @@ protected: Builder.defineMacro("__ELF__"); } + static bool shouldUseInlineAtomic(const llvm::Triple &T) { + // On linux, binaries targeting old cpus call functions in libgcc to + // perform atomic operations. The implementation in libgcc then calls into + // the kernel which on armv6 and newer uses ldrex and strex. The net result + // is that if we assume the kernel is at least as recent as the hardware, + // it is safe to use atomic instructions on armv6 and newer. + if (T.getOS() != llvm::Triple::Linux) + return false; + StringRef ArchName = T.getArchName(); + if (ArchName.startswith("armv6") || ArchName.startswith("armv7")) + return true; + return false; + } + public: RTEMSTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts) : OSTargetInfo(Triple, Opts) { diff --git a/clang/test/CodeGen/linux-arm-atomic.c b/clang/test/CodeGen/linux-arm-atomic.c index 116925a5..0e0fa902 100644 --- a/clang/test/CodeGen/linux-arm-atomic.c +++ b/clang/test/CodeGen/linux-arm-atomic.c @@ -1,5 +1,15 @@ // RUN: %clang_cc1 %s -emit-llvm -o - -triple=armv7-unknown-linux | FileCheck %s // RUN: %clang_cc1 %s -emit-llvm -o - -triple=armv6-unknown-linux | FileCheck %s + +typedef int _Atomic_word; +_Atomic_word exchange_and_add(volatile _Atomic_word *__mem, int __val) { + return __atomic_fetch_add(__mem, __val, __ATOMIC_ACQ_REL); +} + +// CHECK: define {{.*}} @exchange_and_add +// CHECK: atomicrmw {{.*}} add +// RUN: %clang_cc1 %s -emit-llvm -o - -triple=armv7-unknown-linux | FileCheck %s +// RUN: %clang_cc1 %s -emit-llvm -o - -triple=armv6-unknown-linux | FileCheck %s // RUN: %clang_cc1 %s -emit-llvm -o - -triple=thumbv7-unknown-linux | FileCheck %s // RUN: %clang_cc1 %s -emit-llvm -o - -triple=armv6-unknown-freebsd | FileCheck %s // RUN: %clang_cc1 %s -emit-llvm -o - -triple=armv6-unknown-bitrig | FileCheck %s -- 2.30.2