[ARM] Pass subtarget feature "+reserve-r9" instead of passing backend

option "-arm-reserve-r9".

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/D11319

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@242736 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 3ae055801b8ccdb17ce74ba7f5c5b55ce4b1986d..8e5e9804a36f2fc5a6fe48c39a05ea24ae8a2bf0 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -719,6 +719,12 @@ static void getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
       Features.push_back("+long-calls");
   }
 
+  // llvm does not support reserving registers in general. There is support
+  // for reserving r9 on ARM though (defined as a platform-specific register
+  // in ARM EABI).
+  if (Args.hasArg(options::OPT_ffixed_r9))
+    Features.push_back("+reserve-r9");
+
   // The kext linker doesn't know how to deal with movw/movt.
   if (KernelOrKext)
     Features.push_back("+no-movt");
@@ -828,13 +834,6 @@ void Clang::AddARMTargetArgs(const ArgList &Args, ArgStringList &CmdArgs,
                     options::OPT_mno_implicit_float, true))
     CmdArgs.push_back("-no-implicit-float");
 
-  // llvm does not support reserving registers in general. There is support
-  // for reserving r9 on ARM though (defined as a platform-specific register
-  // in ARM EABI).
-  if (Args.hasArg(options::OPT_ffixed_r9)) {
-    CmdArgs.push_back("-backend-option");
-    CmdArgs.push_back("-arm-reserve-r9");
-  }
 }
 
 /// getAArch64TargetCPU - Get the (LLVM) name of the AArch64 cpu we are

diff --git a/test/Driver/arm-fixed-r9.c b/test/Driver/arm-fixed-r9.c
index 2cec8b4c4fc83d5dbe1d9d0aed5154fac40bddc9..74ac336bd7f01e632e9276351759b56adfabdad2 100644 (file)
--- a/test/Driver/arm-fixed-r9.c
+++ b/test/Driver/arm-fixed-r9.c
@@ -1,4 +1,4 @@
 // RUN: %clang -target arm-none-gnueabi -ffixed-r9 -### %s 2> %t
 // RUN: FileCheck --check-prefix=CHECK-FIXED-R9 < %t %s
 
-// CHECK-FIXED-R9: "-backend-option" "-arm-reserve-r9"
+// CHECK-FIXED-R9: "-target-feature" "+reserve-r9"