The PPC global base register cannot be r0

The global base register cannot be r0 because it might end up as the first
argument to addi or addis. Fixes PR18316.

I don't have a small stable test case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203054 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index 44821d31b5194a9fc69171fe679dd5409eff5784..65ea49a8e2ba5f7ef2f7f79f6aae3e6c30ca35a6 100644 (file)
--- a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -272,11 +272,11 @@ SDNode *PPCDAGToDAGISel::getGlobalBaseReg() {
     DebugLoc dl;
 
     if (PPCLowering.getPointerTy() == MVT::i32) {
-      GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
+      GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::GPRC_NOR0RegClass);
       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR));
       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
     } else {
-      GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::G8RCRegClass);
+      GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::G8RC_NOX0RegClass);
       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR8));
       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR8), GlobalBaseReg);
     }