From: Jim Grosbach <grosbach@apple.com>
Date: Mon, 26 Aug 2013 20:07:25 +0000 (+0000)
Subject: ARM: Fix ELF global base reg intialization.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=bb4066123d91c0347cb6333caca527d1a979e703;p=oota-llvm.git

ARM: Fix ELF global base reg intialization.

The create machine code wasn't properly in SSA, which the machine verifier
properly complains about. Now that fast-isel is closer to verifier clean,
errors like this show up more clearly.

Additionally, the Thumb pseudo tPICADD was used for both ARM and Thumb
mode functions, which is obviously wrong. Fix that along the way.

Test case is part of the following commit which will finish making an
additional fast-isel test verifier clean an enable it for the
regression test suite. This commit is separate since its not just
a verifier cleanup, but an actual correctness issue.

rdar://12594152 (for the fast-isel verifier aspects)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189269 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/ARM/ARMInstrInfo.cpp b/lib/Target/ARM/ARMInstrInfo.cpp
index 868dd47743b..3508795ddcc 100644
--- a/lib/Target/ARM/ARMInstrInfo.cpp
+++ b/lib/Target/ARM/ARMInstrInfo.cpp
@@ -22,6 +22,7 @@
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/MC/MCAsmInfo.h"
@@ -119,20 +120,24 @@ namespace {
       MachineBasicBlock &FirstMBB = MF.front();
       MachineBasicBlock::iterator MBBI = FirstMBB.begin();
       DebugLoc DL = FirstMBB.findDebugLoc(MBBI);
-      unsigned GlobalBaseReg = AFI->getGlobalBaseReg();
+      unsigned TempReg =
+          MF.getRegInfo().createVirtualRegister(&ARM::rGPRRegClass);
       unsigned Opc = TM->getSubtarget<ARMSubtarget>().isThumb2() ?
                      ARM::t2LDRpci : ARM::LDRcp;
       const TargetInstrInfo &TII = *TM->getInstrInfo();
       MachineInstrBuilder MIB = BuildMI(FirstMBB, MBBI, DL,
-                                        TII.get(Opc), GlobalBaseReg)
+                                        TII.get(Opc), TempReg)
                                 .addConstantPoolIndex(Idx);
       if (Opc == ARM::LDRcp)
         MIB.addImm(0);
       AddDefaultPred(MIB);
 
       // Fix the GOT address by adding pc.
+      unsigned GlobalBaseReg = AFI->getGlobalBaseReg();
+      Opc = TM->getSubtarget<ARMSubtarget>().isThumb2() ? ARM::tPICADD
+                                                        : ARM::PICADD;
       BuildMI(FirstMBB, MBBI, DL, TII.get(ARM::tPICADD), GlobalBaseReg)
-          .addReg(GlobalBaseReg).addImm(ARMPCLabelIndex);
+          .addReg(TempReg).addImm(ARMPCLabelIndex);
 
       return true;
     }