An attempt to fix the problem Anton reported with

ARM tail calls.  Don't know if it works, but it
doesn't break Darwin.

llvm-svn: 106309

llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp

@@ -1658,7 +1658,8 @@ emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const {
         addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
                          JumpTarget.getTargetFlags());
     } else if (RetOpcode == ARM::TCRETURNdiND) {
-      BuildMI(MBB, MBBI, dl, TII.get(ARM::TAILJMPdND)).
+      BuildMI(MBB, MBBI, dl,
+            TII.get(STI.isThumb() ? ARM::TAILJMPdNDt : ARM::TAILJMPdND)).
         addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
                          JumpTarget.getTargetFlags());
     } else if (RetOpcode == ARM::TCRETURNri) {

llvm/lib/Target/ARM/ARMInstrInfo.td

@@ -1085,7 +1085,11 @@ let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1 in {
 
   def TAILJMPdND : ABXI<0b1010, (outs), (ins brtarget:$dst, variable_ops),
                  IIC_Br, "b.w\t$dst  @ TAILCALL",
-                 []>, Requires<[IsNotDarwin]>;
+                 []>, Requires<[IsARM, IsNotDarwin]>;
+
+  def TAILJMPdNDt : ABXI<0b1010, (outs), (ins brtarget:$dst, variable_ops),
+                 IIC_Br, "b\t$dst  @ TAILCALL",
+                 []>, Requires<[IsThumb, IsNotDarwin]>;
 
   def TAILJMPrND : AXI<(outs), (ins tGPR:$dst, variable_ops),
                    BrMiscFrm, IIC_Br, "bx\t$dst  @ TAILCALL",

llvm/utils/TableGen/ARMDecoderEmitter.cpp

@@ -1579,6 +1579,7 @@ bool ARMDecoderEmitter::ARMDEBackend::populateInstruction(
     if (Name == "TCRETURNdi" || Name == "TCRETURNdiND" ||
         Name == "TCRETURNri" || Name == "TCRETURNriND" ||
         Name == "TAILJMPd"  || Name == "TAILJMPdND" ||
+        Name == "TAILJMPdNDt" ||
         Name == "TAILJMPr"  || Name == "TAILJMPrND" ||
         Name == "MOVr_TC")
       return false;