Fix the remaining atomic intrinsics to use the right register classes on Thumb2,
and add some basic tests for them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132235 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 682af2f..f23d890 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -4983,8 +4983,14 @@
   unsigned ptr = MI->getOperand(1).getReg();
   unsigned incr = MI->getOperand(2).getReg();
   DebugLoc dl = MI->getDebugLoc();
-
   bool isThumb2 = Subtarget->isThumb2();
+
+  MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
+  if (isThumb2) {
+    MRI.constrainRegClass(dest, ARM::rGPRRegisterClass);
+    MRI.constrainRegClass(ptr, ARM::rGPRRegisterClass);
+  }
+
   unsigned ldrOpc, strOpc;
   switch (Size) {
   default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
@@ -5013,10 +5019,10 @@
                   BB->end());
   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
 
-  MachineRegisterInfo &RegInfo = MF->getRegInfo();
-  unsigned scratch = RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
-  unsigned scratch2 = (!BinOpcode) ? incr :
-    RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
+  TargetRegisterClass *TRC =
+    isThumb2 ? ARM::tGPRRegisterClass : ARM::GPRRegisterClass;
+  unsigned scratch = MRI.createVirtualRegister(TRC);
+  unsigned scratch2 = (!BinOpcode) ? incr : MRI.createVirtualRegister(TRC);
 
   //  thisMBB:
   //   ...
@@ -5079,8 +5085,14 @@
   unsigned incr = MI->getOperand(2).getReg();
   unsigned oldval = dest;
   DebugLoc dl = MI->getDebugLoc();
-
   bool isThumb2 = Subtarget->isThumb2();
+
+  MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
+  if (isThumb2) {
+    MRI.constrainRegClass(dest, ARM::rGPRRegisterClass);
+    MRI.constrainRegClass(ptr, ARM::rGPRRegisterClass);
+  }
+
   unsigned ldrOpc, strOpc, extendOpc;
   switch (Size) {
   default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
@@ -5112,9 +5124,10 @@
                   BB->end());
   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
 
-  MachineRegisterInfo &RegInfo = MF->getRegInfo();
-  unsigned scratch = RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
-  unsigned scratch2 = RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
+  TargetRegisterClass *TRC =
+    isThumb2 ? ARM::tGPRRegisterClass : ARM::GPRRegisterClass;
+  unsigned scratch = MRI.createVirtualRegister(TRC);
+  unsigned scratch2 = MRI.createVirtualRegister(TRC);
 
   //  thisMBB:
   //   ...
@@ -5135,7 +5148,7 @@
 
   // Sign extend the value, if necessary.
   if (signExtend && extendOpc) {
-    oldval = RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
+    oldval = MRI.createVirtualRegister(ARM::GPRRegisterClass);
     AddDefaultPred(BuildMI(BB, dl, TII->get(extendOpc), oldval).addReg(dest));
   }