[IRBuilder] Migrate fcmp to folding API

This was one of the last leftovers still using a Create-style
instead of Fold-style API. Convert FoldICmp into FoldCmp so it
can handle both icmp and fcmp.

Author: nikic

llvm/include/llvm/Analysis/InstSimplifyFolder.h

@@ -72,8 +72,8 @@ class InstSimplifyFolder final : public IRBuilderFolder {
     return simplifyUnOp(Opc, V, FMF, SQ);
   }
 
-  Value *FoldICmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
-    return simplifyICmpInst(P, LHS, RHS, SQ);
+  Value *FoldCmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
+    return simplifyCmpInst(P, LHS, RHS, SQ);
   }
 
   Value *FoldGEP(Type *Ty, Value *Ptr, ArrayRef<Value *> IdxList,
@@ -139,15 +139,6 @@ class InstSimplifyFolder final : public IRBuilderFolder {
       return C; // avoid calling Fold
     return ConstFolder.CreatePointerBitCastOrAddrSpaceCast(C, DestTy);
   }
-
-  //===--------------------------------------------------------------------===//
-  // Compare Instructions
-  //===--------------------------------------------------------------------===//
-
-  Value *CreateFCmp(CmpInst::Predicate P, Constant *LHS,
-                    Constant *RHS) const override {
-    return ConstFolder.CreateFCmp(P, LHS, RHS);
-  }
 };
 
 } // end namespace llvm

llvm/include/llvm/Analysis/TargetFolder.h

@@ -99,7 +99,7 @@ class TargetFolder final : public IRBuilderFolder {
     return FoldBinOp(Opc, LHS, RHS);
   }
 
-  Value *FoldICmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
+  Value *FoldCmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
     auto *LC = dyn_cast<Constant>(LHS);
     auto *RC = dyn_cast<Constant>(RHS);
     if (LC && RC)
@@ -216,15 +216,6 @@ class TargetFolder final : public IRBuilderFolder {
       return C; // avoid calling Fold
     return Fold(ConstantExpr::getPointerBitCastOrAddrSpaceCast(C, DestTy));
   }
-
-  //===--------------------------------------------------------------------===//
-  // Compare Instructions
-  //===--------------------------------------------------------------------===//
-
-  Constant *CreateFCmp(CmpInst::Predicate P, Constant *LHS,
-                       Constant *RHS) const override {
-    return Fold(ConstantExpr::getCompare(P, LHS, RHS));
-  }
 };
 
 }

llvm/include/llvm/IR/ConstantFolder.h

@@ -95,7 +95,7 @@ class ConstantFolder final : public IRBuilderFolder {
     return nullptr;
   }
 
-  Value *FoldICmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
+  Value *FoldCmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
     auto *LC = dyn_cast<Constant>(LHS);
     auto *RC = dyn_cast<Constant>(RHS);
     if (LC && RC)
@@ -201,15 +201,6 @@ class ConstantFolder final : public IRBuilderFolder {
                                                 Type *DestTy) const override {
     return ConstantExpr::getPointerBitCastOrAddrSpaceCast(C, DestTy);
   }
-
-  //===--------------------------------------------------------------------===//
-  // Compare Instructions
-  //===--------------------------------------------------------------------===//
-
-  Constant *CreateFCmp(CmpInst::Predicate P, Constant *LHS,
-                       Constant *RHS) const override {
-    return ConstantExpr::getCompare(P, LHS, RHS);
-  }
 };
 
 } // end namespace llvm

llvm/include/llvm/IR/IRBuilder.h

@@ -2350,7 +2350,7 @@ class IRBuilderBase {
 
   Value *CreateICmp(CmpInst::Predicate P, Value *LHS, Value *RHS,
                     const Twine &Name = "") {
-    if (auto *V = Folder.FoldICmp(P, LHS, RHS))
+    if (auto *V = Folder.FoldCmp(P, LHS, RHS))
       return V;
     return Insert(new ICmpInst(P, LHS, RHS), Name);
   }

llvm/include/llvm/IR/IRBuilderFolder.h

@@ -48,8 +48,8 @@ class IRBuilderFolder {
   virtual Value *FoldUnOpFMF(Instruction::UnaryOps Opc, Value *V,
                              FastMathFlags FMF) const = 0;
 
-  virtual Value *FoldICmp(CmpInst::Predicate P, Value *LHS,
-                          Value *RHS) const = 0;
+  virtual Value *FoldCmp(CmpInst::Predicate P, Value *LHS,
+                         Value *RHS) const = 0;
 
   virtual Value *FoldGEP(Type *Ty, Value *Ptr, ArrayRef<Value *> IdxList,
                          bool IsInBounds = false) const = 0;
@@ -84,13 +84,6 @@ class IRBuilderFolder {
   virtual Value *CreatePointerCast(Constant *C, Type *DestTy) const = 0;
   virtual Value *CreatePointerBitCastOrAddrSpaceCast(Constant *C,
                                                      Type *DestTy) const = 0;
-
-  //===--------------------------------------------------------------------===//
-  // Compare Instructions
-  //===--------------------------------------------------------------------===//
-
-  virtual Value *CreateFCmp(CmpInst::Predicate P, Constant *LHS,
-                            Constant *RHS) const = 0;
 };
 
 } // end namespace llvm

llvm/include/llvm/IR/NoFolder.h

@@ -70,7 +70,7 @@ class NoFolder final : public IRBuilderFolder {
     return nullptr;
   }
 
-  Value *FoldICmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
+  Value *FoldCmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
     return nullptr;
   }
 
@@ -129,15 +129,6 @@ class NoFolder final : public IRBuilderFolder {
       Constant *C, Type *DestTy) const override {
     return CastInst::CreatePointerBitCastOrAddrSpaceCast(C, DestTy);
   }
-
-  //===--------------------------------------------------------------------===//
-  // Compare Instructions
-  //===--------------------------------------------------------------------===//
-
-  Instruction *CreateFCmp(CmpInst::Predicate P,
-                          Constant *LHS, Constant *RHS) const override {
-    return new FCmpInst(P, LHS, RHS);
-  }
 };
 
 } // end namespace llvm

llvm/lib/IR/IRBuilder.cpp

@@ -1053,9 +1053,8 @@ Value *IRBuilderBase::CreateFCmpHelper(
     return CreateConstrainedFPCmp(ID, P, LHS, RHS, Name);
   }
 
-  if (auto *LC = dyn_cast<Constant>(LHS))
-    if (auto *RC = dyn_cast<Constant>(RHS))
-      return Insert(Folder.CreateFCmp(P, LC, RC), Name);
+  if (auto *V = Folder.FoldCmp(P, LHS, RHS))
+    return V;
   return Insert(setFPAttrs(new FCmpInst(P, LHS, RHS), FPMathTag, FMF), Name);
 }