From ad438a95c528c4a2013e3e7fb99ea9a260143eb3 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Thu, 24 Oct 2019 19:43:56 -0400
Subject: [PATCH] avoid passing -march=native when not supported

Clang does not support -march=native for all targets.
Arguably it should always work, but in reality it gives:
error: the clang compiler does not support '-march=native'
If we move CPU detection logic into Zig itelf, we will not need this,
instead we will always pass target features and CPU configuration explicitly.
For now, we simply avoid passing the flag when it is known to not be
supported.
---
 src/codegen.cpp |  4 +++-
 src/target.cpp  | 16 +++++++++++++---
 src/target.hpp  |  1 +
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/codegen.cpp b/src/codegen.cpp
index 1c21a4a527..ba189baf89 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -8762,7 +8762,9 @@ void add_cc_args(CodeGen *g, ZigList<const char *> &args, const char *out_dep_pa
     }
 
     if (g->zig_target->is_native) {
-        args.append("-march=native");
+        if (target_supports_clang_march_native(g->zig_target)) {
+            args.append("-march=native");
+        }
     } else {
         args.append("-target");
         args.append(buf_ptr(&g->llvm_triple_str));
diff --git a/src/target.cpp b/src/target.cpp
index 1cab9253a0..9af42b7d9d 100644
--- a/src/target.cpp
+++ b/src/target.cpp
@@ -1583,9 +1583,19 @@ bool target_os_requires_libc(Os os) {
 }
 
 bool target_supports_fpic(const ZigTarget *target) {
-  // This is not whether the target supports Position Independent Code, but whether the -fPIC
-  // C compiler argument is valid.
-  return target->os != OsWindows;
+    // This is not whether the target supports Position Independent Code, but whether the -fPIC
+    // C compiler argument is valid.
+    return target->os != OsWindows;
+}
+
+bool target_supports_clang_march_native(const ZigTarget *target) {
+    // Whether clang supports -march=native on this target.
+    // Arguably it should always work, but in reality it gives:
+    // error: the clang compiler does not support '-march=native'
+    // If we move CPU detection logic into Zig itelf, we will not need this,
+    // instead we will always pass target features and CPU configuration explicitly.
+    return target->arch != ZigLLVM_aarch64 &&
+        target->arch != ZigLLVM_aarch64_be;
 }
 
 bool target_supports_stack_probing(const ZigTarget *target) {
diff --git a/src/target.hpp b/src/target.hpp
index f4c638f196..e6b152be53 100644
--- a/src/target.hpp
+++ b/src/target.hpp
@@ -182,6 +182,7 @@ bool target_can_build_libc(const ZigTarget *target);
 const char *target_libc_generic_name(const ZigTarget *target);
 bool target_is_libc_lib_name(const ZigTarget *target, const char *name);
 bool target_supports_fpic(const ZigTarget *target);
+bool target_supports_clang_march_native(const ZigTarget *target);
 bool target_requires_pic(const ZigTarget *target, bool linking_libc);
 bool target_requires_pie(const ZigTarget *target);
 bool target_abi_is_gnu(ZigLLVM_EnvironmentType abi);