[Driver,AArch64] Add support for -mcpu=native.

This patches adds support for passing -mcpu=native for AArch64. It will
get turned into the host CPU name, before we get the target features.

CPU = native is handled in a similar fashion in
getAArch64MicroArchFetauresFromMtune and getAArch64TargetCPU already.

Having a good test case for this is hard, as it depends on the host CPU
of the machine running the test. But we can check that native has been
replaced with something else.

When cross-compiling, we will get a CPU name from the host architecture
and get ` the clang compiler does not support '-mcpu=native'` as error
message, which seems reasonable to me.

Reviewers: rengolin, peter.smith, dlj, javed.absar, t.p.northover

Reviewed By: peter.smith

Tags: #clang

Differential Revision: https://reviews.llvm.org/D48931

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@336429 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Driver/ToolChains/Arch/AArch64.cpp b/lib/Driver/ToolChains/Arch/AArch64.cpp
index 7bac69687a975a9a2f45f1c781c020898f60e276..5114279b4b4583457a80de800b10959b40831fd9 100644 (file)
--- a/lib/Driver/ToolChains/Arch/AArch64.cpp
+++ b/lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -69,6 +69,9 @@ static bool DecodeAArch64Mcpu(const Driver &D, StringRef Mcpu, StringRef &CPU,
   std::pair<StringRef, StringRef> Split = Mcpu.split("+");
   CPU = Split.first;
 
+  if (CPU == "native")
+    CPU = llvm::sys::getHostCPUName();
+
   if (CPU == "generic") {
     Features.push_back("+neon");
   } else {

diff --git a/test/Driver/aarch64-cpus.c b/test/Driver/aarch64-cpus.c
index 8c7f06052ffb7e463a43751cd95c2d8760a3b98a..330af351182d03cb7c5cafb93a92e23d8038326f 100644 (file)
--- a/test/Driver/aarch64-cpus.c
+++ b/test/Driver/aarch64-cpus.c
@@ -15,6 +15,11 @@
 
 // ARM64-GENERIC: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "generic"
 
+// We cannot check much for -mcpu=native, but it should be replaced by either generic or a valid
+// Arm cpu string, depending on the host.
+// RUN: %clang -target arm64 -mcpu=native -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-NATIVE %s
+// ARM64-NATIVE-NOT: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "native"
+
 // RUN: %clang -target arm64-apple-darwin -arch arm64 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-DARWIN %s
 // ARM64-DARWIN: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "cyclone"