AMDGPU: Move isSDNodeSourceOfDivergence() implementation to SITargetLowering

Summary:
The code that handles ISD:Register and ISD::CopyFromReg assumes
the target is amdgcn, so this is broken on r600.  We don't
need this analysis on r600 anyway so we can safely move
it to SITargetLowering.

Reviewers: alex-t, arsenm, nhaehnle

Reviewed By: arsenm

Subscribers: msearles, kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D46298

llvm-svn: 334607

4 files changed, 69 insertions, 71 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index 259fdafd011..148de14dd5e 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -784,75 +784,6 @@ bool AMDGPUTargetLowering::isSDNodeAlwaysUniform(const SDNode * N) const {
   }
 }
 
-bool AMDGPUTargetLowering::isSDNodeSourceOfDivergence(const SDNode * N,
-  FunctionLoweringInfo * FLI, DivergenceAnalysis * DA) const
-{
-  switch (N->getOpcode()) {
-    case ISD::Register:
-    case ISD::CopyFromReg:
-    {
-      const RegisterSDNode *R = nullptr;
-      if (N->getOpcode() == ISD::Register) {
-        R = dyn_cast<RegisterSDNode>(N);
-      }
-      else {
-        R = dyn_cast<RegisterSDNode>(N->getOperand(1));
-      }
-      if (R)
-      {
-        const MachineFunction * MF = FLI->MF;
-        const SISubtarget &ST = MF->getSubtarget<SISubtarget>();
-        const MachineRegisterInfo &MRI = MF->getRegInfo();
-        const SIRegisterInfo &TRI = ST.getInstrInfo()->getRegisterInfo();
-        unsigned Reg = R->getReg();
-        if (TRI.isPhysicalRegister(Reg))
-          return TRI.isVGPR(MRI, Reg);
-
-        if (MRI.isLiveIn(Reg)) {
-          // workitem.id.x workitem.id.y workitem.id.z
-          // Any VGPR formal argument is also considered divergent
-          if ((MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_X) ||
-              (MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_Y) ||
-              (MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_Z) ||
-              (TRI.isVGPR(MRI, Reg)))
-              return true;
-          // Formal arguments of non-entry functions
-          // are conservatively considered divergent
-          else if (!AMDGPU::isEntryFunctionCC(FLI->Fn->getCallingConv()))
-            return true;
-        }
-        return !DA || DA->isDivergent(FLI->getValueFromVirtualReg(Reg));
-      }
-    }
-    break;
-    case ISD::LOAD: {
-      const LoadSDNode *L = dyn_cast<LoadSDNode>(N);
-      if (L->getMemOperand()->getAddrSpace() ==
-          Subtarget->getAMDGPUAS().PRIVATE_ADDRESS)
-        return true;
-    } break;
-    case ISD::CALLSEQ_END:
-    return true;
-    break;
-    case ISD::INTRINSIC_WO_CHAIN:
-    {
-
-    }
-      return AMDGPU::isIntrinsicSourceOfDivergence(
-      cast<ConstantSDNode>(N->getOperand(0))->getZExtValue());
-    case ISD::INTRINSIC_W_CHAIN:
-      return AMDGPU::isIntrinsicSourceOfDivergence(
-      cast<ConstantSDNode>(N->getOperand(1))->getZExtValue());
-    // In some cases intrinsics that are a source of divergence have been
-    // lowered to AMDGPUISD so we also need to check those too.
-    case AMDGPUISD::INTERP_MOV:
-    case AMDGPUISD::INTERP_P1:
-    case AMDGPUISD::INTERP_P2:
-      return true;
-  }
-  return false;
-}
-
 //===---------------------------------------------------------------------===//
 // Target Properties
 //===---------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.h b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.h
index bf4b43df024..a34c963db8e 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.h
@@ -171,8 +171,6 @@ public:
   bool isCheapToSpeculateCttz() const override;
   bool isCheapToSpeculateCtlz() const override;
 
-  bool isSDNodeSourceOfDivergence(const SDNode *N,
-    FunctionLoweringInfo *FLI, DivergenceAnalysis *DA) const override;
   bool isSDNodeAlwaysUniform(const SDNode *N) const override;
   static CCAssignFn *CCAssignFnForCall(CallingConv::ID CC, bool IsVarArg);
   static CCAssignFn *CCAssignFnForReturn(CallingConv::ID CC, bool IsVarArg);
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index 69a4b03f43a..df396e6ad1f 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -8111,3 +8111,69 @@ void SITargetLowering::computeKnownBitsForFrameIndex(const SDValue Op,
   // calculation won't overflow, so assume the sign bit is never set.
   Known.Zero.setHighBits(AssumeFrameIndexHighZeroBits);
 }
+
+bool SITargetLowering::isSDNodeSourceOfDivergence(const SDNode * N,
+  FunctionLoweringInfo * FLI, DivergenceAnalysis * DA) const
+{
+  switch (N->getOpcode()) {
+    case ISD::Register:
+    case ISD::CopyFromReg:
+    {
+      const RegisterSDNode *R = nullptr;
+      if (N->getOpcode() == ISD::Register) {
+        R = dyn_cast<RegisterSDNode>(N);
+      }
+      else {
+        R = dyn_cast<RegisterSDNode>(N->getOperand(1));
+      }
+      if (R)
+      {
+        const MachineFunction * MF = FLI->MF;
+        const SISubtarget &ST = MF->getSubtarget<SISubtarget>();
+        const MachineRegisterInfo &MRI = MF->getRegInfo();
+        const SIRegisterInfo &TRI = ST.getInstrInfo()->getRegisterInfo();
+        unsigned Reg = R->getReg();
+        if (TRI.isPhysicalRegister(Reg))
+          return TRI.isVGPR(MRI, Reg);
+
+        if (MRI.isLiveIn(Reg)) {
+          // workitem.id.x workitem.id.y workitem.id.z
+          // Any VGPR formal argument is also considered divergent
+          if (TRI.isVGPR(MRI, Reg))
+              return true;
+          // Formal arguments of non-entry functions
+          // are conservatively considered divergent
+          else if (!AMDGPU::isEntryFunctionCC(FLI->Fn->getCallingConv()))
+            return true;
+        }
+        return !DA || DA->isDivergent(FLI->getValueFromVirtualReg(Reg));
+      }
+    }
+    break;
+    case ISD::LOAD: {
+      const LoadSDNode *L = dyn_cast<LoadSDNode>(N);
+      if (L->getMemOperand()->getAddrSpace() ==
+          Subtarget->getAMDGPUAS().PRIVATE_ADDRESS)
+        return true;
+    } break;
+    case ISD::CALLSEQ_END:
+    return true;
+    break;
+    case ISD::INTRINSIC_WO_CHAIN:
+    {
+
+    }
+      return AMDGPU::isIntrinsicSourceOfDivergence(
+      cast<ConstantSDNode>(N->getOperand(0))->getZExtValue());
+    case ISD::INTRINSIC_W_CHAIN:
+      return AMDGPU::isIntrinsicSourceOfDivergence(
+      cast<ConstantSDNode>(N->getOperand(1))->getZExtValue());
+    // In some cases intrinsics that are a source of divergence have been
+    // lowered to AMDGPUISD so we also need to check those too.
+    case AMDGPUISD::INTERP_MOV:
+    case AMDGPUISD::INTERP_P1:
+    case AMDGPUISD::INTERP_P2:
+      return true;
+  }
+  return false;
+}
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.h b/llvm/lib/Target/AMDGPU/SIISelLowering.h
index 80454e9bb90..db5a1dc9641 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.h
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.h
@@ -297,6 +297,9 @@ public:
                                      const APInt &DemandedElts,
                                      const SelectionDAG &DAG,
                                      unsigned Depth = 0) const override;
+
+  bool isSDNodeSourceOfDivergence(const SDNode *N,
+    FunctionLoweringInfo *FLI, DivergenceAnalysis *DA) const override;
 };
 
 } // End namespace llvm