AMDGPU/GlobalISel: Assume VGPR for G_FRAME_INDEX

In principle this should behave as any other constant. However
eliminateFrameIndex currently assumes a VALU use and uses a vector
shift. Work around this by selecting to VGPR for now until
eliminateFrameIndex is fixed.

llvm-svn: 373415

diff --git a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
index 67a7f0a..91a0937 100644 (file)
--- a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
@@ -2138,13 +2138,19 @@ AMDGPURegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
   }
   case AMDGPU::G_FCONSTANT:
   case AMDGPU::G_CONSTANT:
-  case AMDGPU::G_FRAME_INDEX:
   case AMDGPU::G_GLOBAL_VALUE:
   case AMDGPU::G_BLOCK_ADDR: {
     unsigned Size = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
     OpdsMapping[0] = AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, Size);
     break;
   }
+  case AMDGPU::G_FRAME_INDEX: {
+    // TODO: This should be the same as other constants, but eliminateFrameIndex
+    // currently assumes VALU uses.
+    unsigned Size = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
+    OpdsMapping[0] = AMDGPU::getValueMapping(AMDGPU::VGPRRegBankID, Size);
+    break;
+  }
   case AMDGPU::G_INSERT: {
     unsigned BankID = isSALUMapping(MI) ? AMDGPU::SGPRRegBankID :
                                           AMDGPU::VGPRRegBankID;

diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-frame-index.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-frame-index.mir
index 77a444d..585fabe 100644 (file)
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-frame-index.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-frame-index.mir
@@ -17,7 +17,7 @@ stack:
 body: |
   bb.0:
     ; CHECK-LABEL: name: test_frame_index_p5
-    ; CHECK: [[FRAME_INDEX:%[0-9]+]]:sgpr(p5) = G_FRAME_INDEX %stack.0.ptr0
+    ; CHECK: [[FRAME_INDEX:%[0-9]+]]:vgpr(p5) = G_FRAME_INDEX %stack.0.ptr0
     %0:_(p5) = G_FRAME_INDEX %stack.0.ptr0
 
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