[ARM] Define a subtarget feature and use it to decide whether long calls should

be emitted.

This is needed to enable ARM long calls for LTO and enable and disable it on a
per-function basis.

Out-of-tree projects currently using EnableARMLongCalls to emit long calls
should start passing "+long-calls" to the feature string (see the changes made
to clang in r241565).

rdar://problem/21529937

Differential Revision: http://reviews.llvm.org/D9364

llvm-svn: 241566

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 9909a6a6d19..dd101df9b63 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -206,6 +206,9 @@ protected:
   /// NaCl TRAP instruction is generated instead of the regular TRAP.
   bool UseNaClTrap;
 
+  /// Generate calls via indirect call instructions.
+  bool GenLongCalls;
+
   /// Target machine allowed unsafe FP math (such as use of NEON fp)
   bool UnsafeFPMath;
 
@@ -342,6 +345,7 @@ public:
   bool hasMPExtension() const { return HasMPExtension; }
   bool hasThumb2DSP() const { return Thumb2DSP; }
   bool useNaClTrap() const { return UseNaClTrap; }
+  bool genLongCalls() const { return GenLongCalls; }
 
   bool hasFP16() const { return HasFP16; }
   bool hasD16() const { return HasD16; }