[GlobalISel] Remove ConstantFoldingMIRBuilder

[foad]

Summary

ConstantFoldingMIRBuilder was an experiment which is not used for
anything. The constant folding functionality is now part of
CSEMIRBuilder.

[dsanders]

I'm not aware of anything still using it either. LGTM

llvm/include/llvm/CodeGen/GlobalISel/ConstantFoldingMIRBuilder.h

-//===-- llvm/CodeGen/GlobalISel/ConstantFoldingMIRBuilder.h  --*- C++ -*-==//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-/// \file
-/// This file implements a version of MachineIRBuilder which does trivial
-/// constant folding.
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_CODEGEN_GLOBALISEL_CONSTANTFOLDINGMIRBUILDER_H
-#define LLVM_CODEGEN_GLOBALISEL_CONSTANTFOLDINGMIRBUILDER_H
-
-#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
-#include "llvm/CodeGen/GlobalISel/Utils.h"
-
-namespace llvm {
-
-/// An MIRBuilder which does trivial constant folding of binary ops.
-/// Calls to buildInstr will also try to constant fold binary ops.
-class ConstantFoldingMIRBuilder : public MachineIRBuilder {
-public:
-  // Pull in base class constructors.
-  using MachineIRBuilder::MachineIRBuilder;
-
-  virtual ~ConstantFoldingMIRBuilder() = default;
-
-  // Try to provide an overload for buildInstr for binary ops in order to
-  // constant fold.
-  MachineInstrBuilder buildInstr(unsigned Opc, ArrayRef<DstOp> DstOps,
-                                 ArrayRef<SrcOp> SrcOps,
-                                 Optional<unsigned> Flags = None) override {
-    switch (Opc) {
-    default:
-      break;
-    case TargetOpcode::G_ADD:
-    case TargetOpcode::G_AND:
-    case TargetOpcode::G_ASHR:
-    case TargetOpcode::G_LSHR:
-    case TargetOpcode::G_MUL:
-    case TargetOpcode::G_OR:
-    case TargetOpcode::G_SHL:
-    case TargetOpcode::G_SUB:
-    case TargetOpcode::G_XOR:
-    case TargetOpcode::G_UDIV:
-    case TargetOpcode::G_SDIV:
-    case TargetOpcode::G_UREM:
-    case TargetOpcode::G_SREM: {
-      assert(DstOps.size() == 1 && "Invalid dst ops");
-      assert(SrcOps.size() == 2 && "Invalid src ops");
-      const DstOp &Dst = DstOps[0];
-      const SrcOp &Src0 = SrcOps[0];
-      const SrcOp &Src1 = SrcOps[1];
-      if (auto MaybeCst =
-              ConstantFoldBinOp(Opc, Src0.getReg(), Src1.getReg(), *getMRI()))
-        return buildConstant(Dst, MaybeCst->getSExtValue());
-      break;
-    }
-    case TargetOpcode::G_SEXT_INREG: {
-      assert(DstOps.size() == 1 && "Invalid dst ops");
-      assert(SrcOps.size() == 2 && "Invalid src ops");
-      const DstOp &Dst = DstOps[0];
-      const SrcOp &Src0 = SrcOps[0];
-      const SrcOp &Src1 = SrcOps[1];
-      if (auto MaybeCst =
-              ConstantFoldExtOp(Opc, Src0.getReg(), Src1.getImm(), *getMRI()))
-        return buildConstant(Dst, MaybeCst->getSExtValue());
-      break;
-    }
-    }
-    return MachineIRBuilder::buildInstr(Opc, DstOps, SrcOps);
-  }
-};
-} // namespace llvm
-
-#endif // LLVM_CODEGEN_GLOBALISEL_CONSTANTFOLDINGMIRBUILDER_H

llvm/unittests/CodeGen/GlobalISel/ConstantFoldingTest.cpp

 //===- ConstantFoldingTest.cpp -------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "GISelMITest.h"
-#include "llvm/CodeGen/GlobalISel/ConstantFoldingMIRBuilder.h"
+#include "llvm/CodeGen/GlobalISel/CSEMIRBuilder.h"
 #include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
 #include "llvm/CodeGen/GlobalISel/Utils.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "gtest/gtest.h"
 
 using namespace llvm;
 
 namespace {
 
 TEST_F(AArch64GISelMITest, FoldWithBuilder) {
   setUp();
   if (!TM)
     return;
   // Try to use the FoldableInstructionsBuilder to build binary ops.
-  ConstantFoldingMIRBuilder CFB(B.getState());
+  CSEMIRBuilder CFB(B.getState());
   LLT s32 = LLT::scalar(32);
   int64_t Cst;
   auto MIBCAdd =
       CFB.buildAdd(s32, CFB.buildConstant(s32, 0), CFB.buildConstant(s32, 1));
   // This should be a constant now.
   bool match = mi_match(MIBCAdd.getReg(0), *MRI, m_ICst(Cst));
   EXPECT_TRUE(match);
   EXPECT_EQ(Cst, 1);
   auto MIBCAdd1 =
       CFB.buildInstr(TargetOpcode::G_ADD, {s32},
                      {CFB.buildConstant(s32, 0), CFB.buildConstant(s32, 1)});
   // This should be a constant now.
   match = mi_match(MIBCAdd1.getReg(0), *MRI, m_ICst(Cst));
   EXPECT_TRUE(match);
   EXPECT_EQ(Cst, 1);
 
   // Try one of the other constructors of MachineIRBuilder to make sure it's
   // compatible.
-  ConstantFoldingMIRBuilder CFB1(*MF);
+  CSEMIRBuilder CFB1(*MF);
   CFB1.setInsertPt(*EntryMBB, EntryMBB->end());
   auto MIBCSub =
       CFB1.buildInstr(TargetOpcode::G_SUB, {s32},
                       {CFB1.buildConstant(s32, 1), CFB1.buildConstant(s32, 1)});
   // This should be a constant now.
   match = mi_match(MIBCSub.getReg(0), *MRI, m_ICst(Cst));
   EXPECT_TRUE(match);
   EXPECT_EQ(Cst, 0);
TEST_F(AArch64GISelMITest, FoldBinOp) {
   EXPECT_EQ(7ULL, FoldGSremInt.getValue().getLimitedValue());
   Optional<APInt> FoldGSremMix =
       ConstantFoldBinOp(TargetOpcode::G_SREM, MIBCst1.getReg(0),
                         MIBFCst2.getReg(0), *MRI);
   EXPECT_TRUE(FoldGSremMix.hasValue());
   EXPECT_EQ(16ULL, FoldGSremMix.getValue().getLimitedValue());
 }
 
-} // namespace
+} // namespace
 

llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp

 //===- PatternMatchTest.cpp -----------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "GISelMITest.h"
-#include "llvm/CodeGen/GlobalISel/ConstantFoldingMIRBuilder.h"
 #include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
 #include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
 #include "llvm/CodeGen/GlobalISel/Utils.h"
 #include "llvm/CodeGen/MIRParser/MIRParser.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/TargetFrameLowering.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"