[GlobalISel] Add GPtrAdd and use it in some combines.

llvm · Jul 29, 2021 · 532c458 · 532c458
1 parent 1c14441
commit 532c458
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Showing 2 changed files with 25 additions and 13 deletions.
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/GenericMachineInstrs.h b/llvm/include/llvm/CodeGen/GlobalISel/GenericMachineInstrs.h
@@ -195,6 +195,17 @@ class GBuildVector : public GMergeLikeOp {
   }
 };
 
+/// Represents a G_PTR_ADD.
+class GPtrAdd : public GenericMachineInstr {
+public:
+  Register getBaseReg() const { return getReg(1); }
+  Register getOffsetReg() const { return getReg(2); }
+
+  static bool classof(const MachineInstr *MI) {
+    return MI->getOpcode() == TargetOpcode::G_PTR_ADD;
+  }
+};
+
 } // namespace llvm
 
 #endif // LLVM_CODEGEN_GLOBALISEL_GENERICMACHINEINSTRS_H
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -2410,9 +2410,9 @@ void CombinerHelper::applyCombineAddP2IToPtrAdd(
 
 bool CombinerHelper::matchCombineConstPtrAddToI2P(MachineInstr &MI,
                                                   int64_t &NewCst) {
-  assert(MI.getOpcode() == TargetOpcode::G_PTR_ADD && "Expected a G_PTR_ADD");
-  Register LHS = MI.getOperand(1).getReg();
-  Register RHS = MI.getOperand(2).getReg();
+  auto &PtrAdd = cast<GPtrAdd>(MI);
+  Register LHS = PtrAdd.getBaseReg();
+  Register RHS = PtrAdd.getOffsetReg();
   MachineRegisterInfo &MRI = Builder.getMF().getRegInfo();
 
   if (auto RHSCst = getConstantVRegSExtVal(RHS, MRI)) {
@@ -2428,12 +2428,12 @@ bool CombinerHelper::matchCombineConstPtrAddToI2P(MachineInstr &MI,
 
 void CombinerHelper::applyCombineConstPtrAddToI2P(MachineInstr &MI,
                                                   int64_t &NewCst) {
-  assert(MI.getOpcode() == TargetOpcode::G_PTR_ADD && "Expected a G_PTR_ADD");
-  Register Dst = MI.getOperand(0).getReg();
+  auto &PtrAdd = cast<GPtrAdd>(MI);
+  Register Dst = PtrAdd.getReg(0);
 
   Builder.setInstrAndDebugLoc(MI);
   Builder.buildConstant(Dst, NewCst);
-  MI.eraseFromParent();
+  PtrAdd.eraseFromParent();
 }
 
 bool CombinerHelper::matchCombineAnyExtTrunc(MachineInstr &MI, Register &Reg) {
@@ -3346,28 +3346,29 @@ void CombinerHelper::applyXorOfAndWithSameReg(
 }
 
 bool CombinerHelper::matchPtrAddZero(MachineInstr &MI) {
-  Register DstReg = MI.getOperand(0).getReg();
+  auto &PtrAdd = cast<GPtrAdd>(MI);
+  Register DstReg = PtrAdd.getReg(0);
   LLT Ty = MRI.getType(DstReg);
   const DataLayout &DL = Builder.getMF().getDataLayout();
 
   if (DL.isNonIntegralAddressSpace(Ty.getScalarType().getAddressSpace()))
     return false;
 
   if (Ty.isPointer()) {
-    auto ConstVal = getConstantVRegVal(MI.getOperand(1).getReg(), MRI);
+    auto ConstVal = getConstantVRegVal(PtrAdd.getBaseReg(), MRI);
     return ConstVal && *ConstVal == 0;
   }
 
   assert(Ty.isVector() && "Expecting a vector type");
-  const MachineInstr *VecMI = MRI.getVRegDef(MI.getOperand(1).getReg());
+  const MachineInstr *VecMI = MRI.getVRegDef(PtrAdd.getBaseReg());
   return isBuildVectorAllZeros(*VecMI, MRI);
 }
 
 void CombinerHelper::applyPtrAddZero(MachineInstr &MI) {
-  assert(MI.getOpcode() == TargetOpcode::G_PTR_ADD);
-  Builder.setInstrAndDebugLoc(MI);
-  Builder.buildIntToPtr(MI.getOperand(0), MI.getOperand(2));
-  MI.eraseFromParent();
+  auto &PtrAdd = cast<GPtrAdd>(MI);
+  Builder.setInstrAndDebugLoc(PtrAdd);
+  Builder.buildIntToPtr(PtrAdd.getReg(0), PtrAdd.getOffsetReg());
+  PtrAdd.eraseFromParent();
 }
 
 /// The second source operand is known to be a power of 2.