make arm-reserve-r9 available for all ARM

r9 is defined as a platform-specific register in the ARM EABI.
It can be reserved for a special purpose or be used as a general
purpose register. Add support for reserving r9 for all ARM, while
leaving the IOS usage unchanged.

Patch by Jeroen Hofstee.

llvm-svn: 188485

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/Target/ARM/ARMSubtarget.cpp b/llvm/lib/Target/ARM/ARMSubtarget.cpp
index c592421d9a5..a94c9425fb5 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.cpp
+++ b/llvm/lib/Target/ARM/ARMSubtarget.cpp
@@ -169,9 +169,10 @@ void ARMSubtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
   if (isAAPCS_ABI())
     stackAlignment = 8;
 
-  if (!isTargetIOS())
+  if (!isTargetIOS()) {
     UseMovt = hasV6T2Ops();
-  else {
+    IsR9Reserved = ReserveR9;
+  } else {
     IsR9Reserved = ReserveR9 | !HasV6Ops;
     UseMovt = DarwinUseMOVT && hasV6T2Ops();
     SupportsTailCall = !getTargetTriple().isOSVersionLT(5, 0);