[mips] Small update to the implementation of eh.return for Mips.

This patch initializes t9 to the handler address, but only if the relocation
model is pic. This handles the case where handler to which eh.return jumps 
points to the start of the function.

Patch by Sasa Stankovic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178588 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Mips/MipsSEInstrInfo.cpp b/lib/Target/Mips/MipsSEInstrInfo.cpp
index 9d08172..ca0315e 100644
--- a/lib/Target/Mips/MipsSEInstrInfo.cpp
+++ b/lib/Target/Mips/MipsSEInstrInfo.cpp
@@ -387,6 +387,7 @@
   unsigned JR = STI.isABI_N64() ? Mips::JR64 : Mips::JR;
   unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
   unsigned RA = STI.isABI_N64() ? Mips::RA_64 : Mips::RA;
+  unsigned T9 = STI.isABI_N64() ? Mips::T9_64 : Mips::T9;
   unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
   unsigned OffsetReg = I->getOperand(0).getReg();
   unsigned TargetReg = I->getOperand(1).getReg();
@@ -394,6 +395,9 @@
   // or   $ra, $v0, $zero
   // addu $sp, $sp, $v1
   // jr   $ra
+  if (TM.getRelocationModel() == Reloc::PIC_)
+    BuildMI(MBB, I, I->getDebugLoc(), TM.getInstrInfo()->get(OR), T9)
+        .addReg(TargetReg).addReg(ZERO);
   BuildMI(MBB, I, I->getDebugLoc(), TM.getInstrInfo()->get(OR), RA)
       .addReg(TargetReg).addReg(ZERO);
   BuildMI(MBB, I, I->getDebugLoc(), TM.getInstrInfo()->get(ADDU), SP)