ARM: enable tail call optimisation on Thumb 2

Tail call optimisation was previously disabled on all targets other than
iOS5.0+.  This enables the tail call optimisation on all Thumb 2 capable
platforms.

The test adjustments are to remove the IR hint "tail" to function invocation.
The tests were designed assuming that tail call optimisations would not kick in
which no longer holds true.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203575 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/Target/ARM/ARMSubtarget.cpp b/lib/Target/ARM/ARMSubtarget.cpp
index d510e7ebf1..69b496f386 100644
--- a/lib/Target/ARM/ARMSubtarget.cpp
+++ b/lib/Target/ARM/ARMSubtarget.cpp
@@ -219,8 +219,10 @@ void ARMSubtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
   if (isTargetMachO()) {
     IsR9Reserved = ReserveR9 | !HasV6Ops;
     SupportsTailCall = !isTargetIOS() || !getTargetTriple().isOSVersionLT(5, 0);
-  } else
+  } else {
     IsR9Reserved = ReserveR9;
+    SupportsTailCall = !isThumb1Only();
+  }
 
   if (!isThumb() || hasThumb2())
     PostRAScheduler = true;