[ARM GlobalISel] Move the check for Thumb higher up

We're currently bailing out for Thumb targets while lowering formal
parameters, but there used to be some other checks before it, which
could've caused some functions (e.g. those without formal parameters) to
sneak through unnoticed.

llvm-svn: 317312

diff --git a/llvm/lib/Target/ARM/ARMCallLowering.cpp b/llvm/lib/Target/ARM/ARMCallLowering.cpp
index e1323cd..9c10a1c 100644 (file)
--- a/llvm/lib/Target/ARM/ARMCallLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMCallLowering.cpp
@@ -417,6 +417,12 @@ struct FormalArgHandler : public IncomingValueHandler {
 bool ARMCallLowering::lowerFormalArguments(MachineIRBuilder &MIRBuilder,
                                            const Function &F,
                                            ArrayRef<unsigned> VRegs) const {
+  auto &TLI = *getTLI<ARMTargetLowering>();
+  auto Subtarget = TLI.getSubtarget();
+
+  if (Subtarget->isThumb())
+    return false;
+
   // Quick exit if there aren't any args
   if (F.arg_empty())
     return true;
@@ -427,12 +433,6 @@ bool ARMCallLowering::lowerFormalArguments(MachineIRBuilder &MIRBuilder,
   auto &MF = MIRBuilder.getMF();
   auto &MBB = MIRBuilder.getMBB();
   auto DL = MF.getDataLayout();
-  auto &TLI = *getTLI<ARMTargetLowering>();
-
-  auto Subtarget = TLI.getSubtarget();
-
-  if (Subtarget->isThumb())
-    return false;
 
   for (auto &Arg : F.args())
     if (!isSupportedType(DL, TLI, Arg.getType()))