[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, 1 insertions, 6 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 607ce767be2..9d25e2cf182 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -60,11 +60,6 @@ STATISTIC(NumTailCalls, "Number of tail calls");
 STATISTIC(NumMovwMovt, "Number of GAs materialized with movw + movt");
 STATISTIC(NumLoopByVals, "Number of loops generated for byval arguments");
 
-cl::opt<bool>
-EnableARMLongCalls("arm-long-calls", cl::Hidden,
-  cl::desc("Generate calls via indirect call instructions"),
-  cl::init(false));
-
 static cl::opt<bool>
 ARMInterworking("arm-interworking", cl::Hidden,
   cl::desc("Enable / disable ARM interworking (for debugging only)"),
@@ -1694,7 +1689,7 @@ ARMTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   bool isLocalARMFunc = false;
   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
 
-  if (EnableARMLongCalls) {
+  if (Subtarget->genLongCalls()) {
     assert((Subtarget->isTargetWindows() ||
             getTargetMachine().getRelocationModel() == Reloc::Static) &&
            "long-calls with non-static relocation model!");