AMDGPU: Always use VGPR indexing on GFX9

Reviewers: arsenm

Subscribers: kzhuravl, wdng, nhaehnle, yaxunl, tony-tye, dstuttard, tpr

Differential Revision: https://reviews.llvm.org/D31157

llvm-svn: 298396
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index dfdc233..ea7d374 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -1667,7 +1667,7 @@
   std::tie(SubReg, Offset)
     = computeIndirectRegAndOffset(TRI, VecRC, SrcReg, Offset);
 
-  bool UseGPRIdxMode = ST.hasVGPRIndexMode() && EnableVGPRIndexMode;
+  bool UseGPRIdxMode = ST.useVGPRIndexMode(EnableVGPRIndexMode);
 
   if (setM0ToIndexFromSGPR(TII, MRI, MI, Offset, UseGPRIdxMode, true)) {
     MachineBasicBlock::iterator I(&MI);
@@ -1769,7 +1769,7 @@
   std::tie(SubReg, Offset) = computeIndirectRegAndOffset(TRI, VecRC,
                                                          SrcVec->getReg(),
                                                          Offset);
-  bool UseGPRIdxMode = ST.hasVGPRIndexMode() && EnableVGPRIndexMode;
+  bool UseGPRIdxMode = ST.useVGPRIndexMode(EnableVGPRIndexMode);
 
   if (Idx->getReg() == AMDGPU::NoRegister) {
     MachineBasicBlock::iterator I(&MI);