[llvm-commits] [llvm] r142458 - /llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp

[Bill Wendling]

Author: void
Date: Tue Oct 18 18:11:05 2011
New Revision: 142458

URL: http://llvm.org/viewvc/llvm-project?rev=142458&view=rev
Log:
For Thumb mode, we need to use a constant pool if the value is too large to be
used with the CMP instruction.

Modified:
    llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp?rev=142458&r1=142457&r2=142458&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp Tue Oct 18 18:11:05 2011
@@ -5809,9 +5809,26 @@
                    .addImm(1)
                    .addMemOperand(FIMMOLd));
 
-    AddDefaultPred(BuildMI(DispatchBB, dl, TII->get(ARM::tCMPi8))
-                   .addReg(NewVReg1)
-                   .addImm(LPadList.size()));
+    if (NumLPads < 256) {
+      AddDefaultPred(BuildMI(DispatchBB, dl, TII->get(ARM::tCMPi8))
+                     .addReg(NewVReg1)
+                     .addImm(NumLPads));
+    } else {
+      MachineConstantPool *ConstantPool = MF->getConstantPool();
+      const Constant *C =
+        ConstantInt::get(Type::getInt32Ty(MF->getFunction()->getContext()),
+                         NumLPads);
+      unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4);
+
+      unsigned VReg1 = MRI->createVirtualRegister(TRC);
+      AddDefaultPred(BuildMI(DispatchBB, dl, TII->get(ARM::tLDRpci))
+                     .addReg(VReg1, RegState::Define)
+                     .addConstantPoolIndex(Idx));
+      AddDefaultPred(BuildMI(DispatchBB, dl, TII->get(ARM::tCMPr))
+                     .addReg(NewVReg1)
+                     .addReg(VReg1));
+    }
+
     BuildMI(DispatchBB, dl, TII->get(ARM::tBcc))
       .addMBB(TrapBB)
       .addImm(ARMCC::HI)