[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
diff --git a/llvm/lib/Target/ARM/ARM.td b/llvm/lib/Target/ARM/ARM.td
index 96b4742..ef609a6 100644
--- a/llvm/lib/Target/ARM/ARM.td
+++ b/llvm/lib/Target/ARM/ARM.td
@@ -150,6 +150,10 @@
def FeatureNaClTrap : SubtargetFeature<"nacl-trap", "UseNaClTrap", "true",
"NaCl trap">;
+def FeatureLongCalls : SubtargetFeature<"long-calls", "GenLongCalls", "true",
+ "Generate calls via indirect call "
+ "instructions">;
+
// ARM ISAs.
def HasV4TOps : SubtargetFeature<"v4t", "HasV4TOps", "true",
"Support ARM v4T instructions">;
diff --git a/llvm/lib/Target/ARM/ARMFastISel.cpp b/llvm/lib/Target/ARM/ARMFastISel.cpp
index 4175b4a..3a36d46 100644
--- a/llvm/lib/Target/ARM/ARMFastISel.cpp
+++ b/llvm/lib/Target/ARM/ARMFastISel.cpp
@@ -49,8 +49,6 @@
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
-extern cl::opt<bool> EnableARMLongCalls;
-
namespace {
// All possible address modes, plus some.
@@ -2246,19 +2244,19 @@
return false;
unsigned CalleeReg = 0;
- if (EnableARMLongCalls) {
+ if (Subtarget->genLongCalls()) {
CalleeReg = getLibcallReg(TLI.getLibcallName(Call));
if (CalleeReg == 0) return false;
}
// Issue the call.
- unsigned CallOpc = ARMSelectCallOp(EnableARMLongCalls);
+ unsigned CallOpc = ARMSelectCallOp(Subtarget->genLongCalls());
MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt,
DbgLoc, TII.get(CallOpc));
// BL / BLX don't take a predicate, but tBL / tBLX do.
if (isThumb2)
AddDefaultPred(MIB);
- if (EnableARMLongCalls)
+ if (Subtarget->genLongCalls())
MIB.addReg(CalleeReg);
else
MIB.addExternalSymbol(TLI.getLibcallName(Call));
@@ -2380,7 +2378,7 @@
bool UseReg = false;
const GlobalValue *GV = dyn_cast<GlobalValue>(Callee);
- if (!GV || EnableARMLongCalls) UseReg = true;
+ if (!GV || Subtarget->genLongCalls()) UseReg = true;
unsigned CalleeReg = 0;
if (UseReg) {
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 607ce76..9d25e2c 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -60,11 +60,6 @@
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 @@
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!");
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.cpp b/llvm/lib/Target/ARM/ARMSubtarget.cpp
index af18eea..fe9743d 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.cpp
+++ b/llvm/lib/Target/ARM/ARMSubtarget.cpp
@@ -172,6 +172,7 @@
AllowsUnalignedMem = false;
Thumb2DSP = false;
UseNaClTrap = false;
+ GenLongCalls = false;
UnsafeFPMath = false;
}
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 9909a6a..dd101df 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -206,6 +206,9 @@
/// 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 @@
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; }