From cd0f3da09c8b80e354b6bcb86529d560b4fbb955 Mon Sep 17 00:00:00 2001
From: Akira Hatanaka <ahatanaka@apple.com>
Date: Thu, 16 Jul 2015 00:43:00 +0000
Subject: [PATCH] [ARM] Pass subtarget feature "+no-movt" instead of passing
 backend option "-arm-use-movt=0".

This change is needed since backend options do not make it to the backend
when doing LTO and are not capable of changing the behavior of code-gen
passes on a per-function basis.

rdar://problem/21529937

Differential Revision: http://reviews.llvm.org/D11025


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@242368 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/Tools.cpp       | 8 ++++----
 test/CodeGen/arm-no-movt.c | 7 +++++++
 test/Driver/arm-no-movt.c  | 9 +++++++++
 3 files changed, 20 insertions(+), 4 deletions(-)
 create mode 100644 test/CodeGen/arm-no-movt.c
 create mode 100644 test/Driver/arm-no-movt.c

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 8c11992f1f..89e3987170 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -718,6 +718,10 @@ static void getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
   } else if (KernelOrKext && (!Triple.isiOS() || Triple.isOSVersionLT(6))) {
       Features.push_back("+long-calls");
   }
+
+  // The kext linker doesn't know how to deal with movw/movt.
+  if (KernelOrKext)
+    Features.push_back("+no-movt");
 }
 
 void Clang::AddARMTargetArgs(const ArgList &Args, ArgStringList &CmdArgs,
@@ -793,10 +797,6 @@ void Clang::AddARMTargetArgs(const ArgList &Args, ArgStringList &CmdArgs,
   if (KernelOrKext) {
     CmdArgs.push_back("-backend-option");
     CmdArgs.push_back("-arm-strict-align");
-
-    // The kext linker doesn't know how to deal with movw/movt.
-    CmdArgs.push_back("-backend-option");
-    CmdArgs.push_back("-arm-use-movt=0");
   }
 
   // -mkernel implies -mstrict-align; don't add the redundant option.
diff --git a/test/CodeGen/arm-no-movt.c b/test/CodeGen/arm-no-movt.c
new file mode 100644
index 0000000000..0773941fb3
--- /dev/null
+++ b/test/CodeGen/arm-no-movt.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -triple thumbv7-apple-ios5  -target-feature +no-movt -emit-llvm -o - %s | FileCheck -check-prefix=NO-MOVT %s
+// RUN: %clang_cc1 -triple thumbv7-apple-ios5 -emit-llvm -o - %s | FileCheck -check-prefix=MOVT %s
+
+// NO-MOVT: attributes #0 = { {{.*}} "target-features"="+no-movt"
+// MOVT-NOT: attributes #0 = { {{.*}} "target-features"="+no-movt"
+
+int foo1(int a) { return a; }
diff --git a/test/Driver/arm-no-movt.c b/test/Driver/arm-no-movt.c
new file mode 100644
index 0000000000..9684d0e16c
--- /dev/null
+++ b/test/Driver/arm-no-movt.c
@@ -0,0 +1,9 @@
+// RUN: %clang -target armv7-apple-darwin -### %s 2>&1 \
+// RUN:    | FileCheck %s -check-prefix CHECK-DEFAULT
+
+// RUN: %clang -target armv7-apple-darwin -mkernel -### %s 2>&1 \
+// RUN:    | FileCheck %s -check-prefix CHECK-KERNEL
+
+// CHECK-DEFAULT-NOT: "-target-feature" "+no-movt"
+
+// CHECK-KERNEL: "-target-feature" "+no-movt"
-- 
2.50.1