Rename ExpandLargeFpConvertPass to ExpandFpPass (#131128)

This is meant as a preparation for PR #130988 "[AMDGPU] Implement IR
expansion for frem instruction" which implements the expansion of
another instruction in this pass. The more general name seems more
appropriate given this change and quite reasonable even without it.

Author: frederik-h

llvm/docs/WritingAnLLVMPass.rst

@@ -652,7 +652,7 @@ default optimization pipelines, e.g. (the output has been trimmed):
   Pre-ISel Intrinsic Lowering
   FunctionPass Manager
     Expand large div/rem
-    Expand large fp convert
+    Expand fp
     Expand Atomic instructions
   SVE intrinsics optimizations
     FunctionPass Manager

llvm/include/llvm/CodeGen/ExpandLargeFpConvert.h renamed to llvm/include/llvm/CodeGen/ExpandFp.h

@@ -1,31 +1,30 @@
-//===- ExpandLargeFpConvert.h -----------------------------------*- C++ -*-===//
+//===- ExpandFp.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
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_CODEGEN_EXPANDLARGEFPCONVERT_H
-#define LLVM_CODEGEN_EXPANDLARGEFPCONVERT_H
+#ifndef LLVM_CODEGEN_EXPANDFP_H
+#define LLVM_CODEGEN_EXPANDFP_H
 
 #include "llvm/IR/PassManager.h"
 
 namespace llvm {
 
 class TargetMachine;
 
-class ExpandLargeFpConvertPass
-    : public PassInfoMixin<ExpandLargeFpConvertPass> {
+class ExpandFpPass : public PassInfoMixin<ExpandFpPass> {
 private:
   const TargetMachine *TM;
 
 public:
-  explicit ExpandLargeFpConvertPass(const TargetMachine *TM_) : TM(TM_) {}
+  explicit ExpandFpPass(const TargetMachine *TM_) : TM(TM_) {}
 
   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
 };
 
 } // end namespace llvm
 
-#endif // LLVM_CODEGEN_EXPANDLARGEFPCONVERT_H
+#endif // LLVM_CODEGEN_EXPANDFP_H

llvm/include/llvm/CodeGen/Passes.h

@@ -529,7 +529,7 @@ namespace llvm {
   FunctionPass *createExpandLargeDivRemPass();
 
   // Expands large div/rem instructions.
-  FunctionPass *createExpandLargeFpConvertPass();
+  FunctionPass *createExpandFpPass();
 
   // This pass expands memcmp() to load/stores.
   FunctionPass *createExpandMemCmpLegacyPass();

llvm/include/llvm/CodeGen/TargetLowering.h

@@ -2148,8 +2148,8 @@ class TargetLoweringBase {
     return MaxDivRemBitWidthSupported;
   }
 
-  /// Returns the size in bits of the maximum larget fp convert the backend
-  /// supports. Larger operations will be expanded by ExpandLargeFPConvert.
+  /// Returns the size in bits of the maximum fp to/from int conversion the
+  /// backend supports. Larger operations will be expanded by ExpandFp.
   unsigned getMaxLargeFPConvertBitWidthSupported() const {
     return MaxLargeFPConvertBitWidthSupported;
   }
@@ -2782,8 +2782,8 @@ class TargetLoweringBase {
     MaxDivRemBitWidthSupported = SizeInBits;
   }
 
-  /// Set the size in bits of the maximum fp convert the backend supports.
-  /// Larger operations will be expanded by ExpandLargeFPConvert.
+  /// Set the size in bits of the maximum fp to/from int conversion the backend
+  /// supports. Larger operations will be expanded by ExpandFp.
   void setMaxLargeFPConvertBitWidthSupported(unsigned SizeInBits) {
     MaxLargeFPConvertBitWidthSupported = SizeInBits;
   }
@@ -3580,8 +3580,9 @@ class TargetLoweringBase {
   /// Larger operations will be expanded by ExpandLargeDivRem.
   unsigned MaxDivRemBitWidthSupported;
 
-  /// Size in bits of the maximum larget fp convert size the backend
-  /// supports. Larger operations will be expanded by ExpandLargeFPConvert.
+  /// Size in bits of the maximum fp to/from int conversion size the
+  /// backend supports. Larger operations will be expanded by
+  /// ExpandFp.
   unsigned MaxLargeFPConvertBitWidthSupported;
 
   /// Size in bits of the minimum cmpxchg or ll/sc operation the

llvm/include/llvm/InitializePasses.h

@@ -105,7 +105,7 @@ void initializeEarlyMachineLICMPass(PassRegistry &);
 void initializeEarlyTailDuplicateLegacyPass(PassRegistry &);
 void initializeEdgeBundlesWrapperLegacyPass(PassRegistry &);
 void initializeEHContGuardTargetsPass(PassRegistry &);
-void initializeExpandLargeFpConvertLegacyPassPass(PassRegistry &);
+void initializeExpandFpLegacyPassPass(PassRegistry &);
 void initializeExpandLargeDivRemLegacyPassPass(PassRegistry &);
 void initializeExpandMemCmpLegacyPassPass(PassRegistry &);
 void initializeExpandPostRALegacyPass(PassRegistry &);

llvm/include/llvm/Passes/CodeGenPassBuilder.h

@@ -30,8 +30,8 @@
 #include "llvm/CodeGen/DetectDeadLanes.h"
 #include "llvm/CodeGen/DwarfEHPrepare.h"
 #include "llvm/CodeGen/EarlyIfConversion.h"
+#include "llvm/CodeGen/ExpandFp.h"
 #include "llvm/CodeGen/ExpandLargeDivRem.h"
-#include "llvm/CodeGen/ExpandLargeFpConvert.h"
 #include "llvm/CodeGen/ExpandMemCmp.h"
 #include "llvm/CodeGen/ExpandPostRAPseudos.h"
 #include "llvm/CodeGen/ExpandReductions.h"
@@ -663,7 +663,7 @@ void CodeGenPassBuilder<Derived, TargetMachineT>::addISelPasses(
 
   addPass(PreISelIntrinsicLoweringPass(&TM));
   addPass(ExpandLargeDivRemPass(&TM));
-  addPass(ExpandLargeFpConvertPass(&TM));
+  addPass(ExpandFpPass(&TM));
 
   derived().addIRPasses(addPass);
   derived().addCodeGenPrepare(addPass);

llvm/include/llvm/Passes/MachinePassRegistry.def

@@ -52,7 +52,7 @@ FUNCTION_PASS("consthoist", ConstantHoistingPass())
 FUNCTION_PASS("dwarf-eh-prepare", DwarfEHPreparePass(TM))
 FUNCTION_PASS("ee-instrument", EntryExitInstrumenterPass(false))
 FUNCTION_PASS("expand-large-div-rem", ExpandLargeDivRemPass(TM))
-FUNCTION_PASS("expand-large-fp-convert", ExpandLargeFpConvertPass(TM))
+FUNCTION_PASS("expand-fp", ExpandFpPass(TM))
 FUNCTION_PASS("expand-memcmp", ExpandMemCmpPass(TM))
 FUNCTION_PASS("expand-reductions", ExpandReductionsPass())
 FUNCTION_PASS("gc-lowering", GCLoweringPass())

llvm/lib/CodeGen/CMakeLists.txt

@@ -57,7 +57,7 @@ add_llvm_component_library(LLVMCodeGen
   EHContGuardTargets.cpp
   ExecutionDomainFix.cpp
   ExpandLargeDivRem.cpp
-  ExpandLargeFpConvert.cpp
+  ExpandFp.cpp
   ExpandMemCmp.cpp
   ExpandPostRAPseudos.cpp
   ExpandReductions.cpp

llvm/lib/CodeGen/CodeGen.cpp

@@ -40,7 +40,7 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeEarlyMachineLICMPass(Registry);
   initializeEarlyTailDuplicateLegacyPass(Registry);
   initializeExpandLargeDivRemLegacyPassPass(Registry);
-  initializeExpandLargeFpConvertLegacyPassPass(Registry);
+  initializeExpandFpLegacyPassPass(Registry);
   initializeExpandMemCmpLegacyPassPass(Registry);
   initializeExpandPostRALegacyPass(Registry);
   initializeFEntryInserterPass(Registry);

llvm/lib/CodeGen/ExpandLargeFpConvert.cpp renamed to llvm/lib/CodeGen/ExpandFp.cpp

@@ -1,20 +1,20 @@
-//===--- ExpandLargeFpConvert.cpp - Expand large fp convert----------------===//
+//===--- ExpandFp.cpp - Expand fp instructions ----------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
+// This pass expands certain floating point instructions at the IR level.
 //
-
-// This pass expands ‘fptoui .. to’, ‘fptosi .. to’, ‘uitofp .. to’,
-// ‘sitofp .. to’ instructions with a bitwidth above a threshold into
-// auto-generated functions. This is useful for targets like x86_64 that cannot
-// lower fp convertions with more than 128 bits.
+// It expands ‘fptoui .. to’, ‘fptosi .. to’, ‘uitofp ..  to’, ‘sitofp
+// .. to’ instructions with a bitwidth above a threshold.  This is
+// useful for targets like x86_64 that cannot lower fp convertions
+// with more than 128 bits.
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/CodeGen/ExpandLargeFpConvert.h"
+#include "llvm/CodeGen/ExpandFp.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/CodeGen/Passes.h"
@@ -33,9 +33,11 @@ using namespace llvm;
 
 static cl::opt<unsigned>
     ExpandFpConvertBits("expand-fp-convert-bits", cl::Hidden,
-                     cl::init(llvm::IntegerType::MAX_INT_BITS),
-                     cl::desc("fp convert instructions on integers with "
-                              "more than <N> bits are expanded."));
+                        cl::init(llvm::IntegerType::MAX_INT_BITS),
+                        cl::desc("fp convert instructions on integers with "
+                                 "more than <N> bits are expanded."));
+
+// clang-format off: preserve formatting of the following example
 
 /// Generate code to convert a fp number to integer, replacing FPToS(U)I with
 /// the generated code. This currently generates code similarly to compiler-rt's
@@ -88,6 +90,7 @@ static cl::opt<unsigned>
 ///
 /// Replace fp to integer with generated code.
 static void expandFPToI(Instruction *FPToI) {
+  // clang-format on
   IRBuilder<> Builder(FPToI);
   auto *FloatVal = FPToI->getOperand(0);
   IntegerType *IntTy = cast<IntegerType>(FPToI->getType());
@@ -224,6 +227,8 @@ static void expandFPToI(Instruction *FPToI) {
   FPToI->eraseFromParent();
 }
 
+// clang-format off: preserve formatting of the following example
+
 /// Generate code to convert a fp number to integer, replacing S(U)IToFP with
 /// the generated code. This currently generates code similarly to compiler-rt's
 /// implementations. This implementation has an implicit assumption that integer
@@ -307,6 +312,7 @@ static void expandFPToI(Instruction *FPToI) {
 ///
 /// Replace integer to fp with generated code.
 static void expandIToFP(Instruction *IToFP) {
+  // clang-format on
   IRBuilder<> Builder(IToFP);
   auto *IntVal = IToFP->getOperand(0);
   IntegerType *IntTy = cast<IntegerType>(IntVal->getType());
@@ -666,13 +672,12 @@ static bool runImpl(Function &F, const TargetLowering &TLI) {
 }
 
 namespace {
-class ExpandLargeFpConvertLegacyPass : public FunctionPass {
+class ExpandFpLegacyPass : public FunctionPass {
 public:
   static char ID;
 
-  ExpandLargeFpConvertLegacyPass() : FunctionPass(ID) {
-    initializeExpandLargeFpConvertLegacyPassPass(
-        *PassRegistry::getPassRegistry());
+  ExpandFpLegacyPass() : FunctionPass(ID) {
+    initializeExpandFpLegacyPassPass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnFunction(Function &F) override {
@@ -689,19 +694,15 @@ class ExpandLargeFpConvertLegacyPass : public FunctionPass {
 };
 } // namespace
 
-PreservedAnalyses ExpandLargeFpConvertPass::run(Function &F,
-                                                FunctionAnalysisManager &FAM) {
+PreservedAnalyses ExpandFpPass::run(Function &F, FunctionAnalysisManager &FAM) {
   const TargetSubtargetInfo *STI = TM->getSubtargetImpl(F);
   return runImpl(F, *STI->getTargetLowering()) ? PreservedAnalyses::none()
                                                : PreservedAnalyses::all();
 }
 
-char ExpandLargeFpConvertLegacyPass::ID = 0;
-INITIALIZE_PASS_BEGIN(ExpandLargeFpConvertLegacyPass, "expand-large-fp-convert",
-                      "Expand large fp convert", false, false)
-INITIALIZE_PASS_END(ExpandLargeFpConvertLegacyPass, "expand-large-fp-convert",
-                    "Expand large fp convert", false, false)
+char ExpandFpLegacyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(ExpandFpLegacyPass, "expand-fp",
+                      "Expand certain fp instructions", false, false)
+INITIALIZE_PASS_END(ExpandFpLegacyPass, "expand-fp", "Expand fp", false, false)
 
-FunctionPass *llvm::createExpandLargeFpConvertPass() {
-  return new ExpandLargeFpConvertLegacyPass();
-}
+FunctionPass *llvm::createExpandFpPass() { return new ExpandFpLegacyPass(); }