Move ExpandMemCmp and MergeIcmp to the middle end

llvm/include/llvm/CodeGen/Passes.h

@@ -519,9 +519,6 @@ namespace llvm {
   // Expands large div/rem instructions.
   FunctionPass *createExpandLargeFpConvertPass();
 
-  // This pass expands memcmp() to load/stores.
-  FunctionPass *createExpandMemCmpLegacyPass();
-
   /// Creates Break False Dependencies pass. \see BreakFalseDeps.cpp
   FunctionPass *createBreakFalseDeps();
 

llvm/include/llvm/InitializePasses.h

@@ -102,8 +102,7 @@ void initializeEarlyTailDuplicatePass(PassRegistry&);
 void initializeEdgeBundlesPass(PassRegistry&);
 void initializeEHContGuardCatchretPass(PassRegistry &);
 void initializeExpandLargeFpConvertLegacyPassPass(PassRegistry&);
-void initializeExpandLargeDivRemLegacyPassPass(PassRegistry&);
-void initializeExpandMemCmpLegacyPassPass(PassRegistry &);
+void initializeExpandLargeDivRemLegacyPassPass(PassRegistry &);
 void initializeExpandPostRAPass(PassRegistry&);
 void initializeExpandReductionsPass(PassRegistry&);
 void initializeExpandVectorPredicationPass(PassRegistry &);

llvm/include/llvm/LinkAllPasses.h

@@ -117,8 +117,7 @@ namespace {
       (void) llvm::createGVNPass();
       (void) llvm::createPostDomTree();
       (void) llvm::createMergeICmpsLegacyPass();
-      (void) llvm::createExpandLargeDivRemPass();
-      (void)llvm::createExpandMemCmpLegacyPass();
+      (void)llvm::createExpandLargeDivRemPass();
       (void) llvm::createExpandVectorPredicationPass();
       std::string buf;
       llvm::raw_string_ostream os(buf);

llvm/include/llvm/Passes/CodeGenPassBuilder.h

@@ -27,7 +27,6 @@
 #include "llvm/CodeGen/CodeGenPrepare.h"
 #include "llvm/CodeGen/DeadMachineInstructionElim.h"
 #include "llvm/CodeGen/DwarfEHPrepare.h"
-#include "llvm/CodeGen/ExpandMemCmp.h"
 #include "llvm/CodeGen/ExpandReductions.h"
 #include "llvm/CodeGen/FreeMachineFunction.h"
 #include "llvm/CodeGen/GCMetadata.h"
@@ -590,16 +589,6 @@ void CodeGenPassBuilder<Derived>::addIRPasses(AddIRPass &addPass) const {
       addPass(PrintFunctionPass(dbgs(), "\n\n*** Code after LSR ***\n"));
   }
 
-  if (getOptLevel() != CodeGenOptLevel::None) {
-    // The MergeICmpsPass tries to create memcmp calls by grouping sequences of
-    // loads and compares. ExpandMemCmpPass then tries to expand those calls
-    // into optimally-sized loads and compares. The transforms are enabled by a
-    // target lowering hook.
-    if (!Opt.DisableMergeICmps)
-      addPass(MergeICmpsPass());
-    addPass(ExpandMemCmpPass(&TM));
-  }
-
   // Run GC lowering passes for builtin collectors
   // TODO: add a pass insertion point here
   addPass(GCLoweringPass());

llvm/include/llvm/CodeGen/ExpandMemCmp.h → llvm/include/llvm/Transforms/Scalar/ExpandMemCmp.h

@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_CODEGEN_EXPANDMEMCMP_H
-#define LLVM_CODEGEN_EXPANDMEMCMP_H
+#ifndef LLVM_TRANSFORMS_SCALAR_EXPANDMEMCMP_H
+#define LLVM_TRANSFORMS_SCALAR_EXPANDMEMCMP_H
 
 #include "llvm/IR/PassManager.h"
 
@@ -16,14 +16,13 @@ namespace llvm {
 class TargetMachine;
 
 class ExpandMemCmpPass : public PassInfoMixin<ExpandMemCmpPass> {
-  const TargetMachine *TM;
 
 public:
-  explicit ExpandMemCmpPass(const TargetMachine *TM_) : TM(TM_) {}
+  explicit ExpandMemCmpPass() {}
 
   PreservedAnalyses run(Function &F, FunctionAnalysisManager &FAM);
 };
 
 } // namespace llvm
 
-#endif // LLVM_CODEGEN_EXPANDMEMCMP_H
+#endif // LLVM_TRANSFORMS_SCALAR_EXPANDMEMCMP_H

llvm/lib/CodeGen/CMakeLists.txt

@@ -57,7 +57,6 @@ add_llvm_component_library(LLVMCodeGen
   ExecutionDomainFix.cpp
   ExpandLargeDivRem.cpp
   ExpandLargeFpConvert.cpp
-  ExpandMemCmp.cpp
   ExpandPostRAPseudos.cpp
   ExpandReductions.cpp
   ExpandVectorPredication.cpp

llvm/lib/CodeGen/CodeGen.cpp

@@ -41,7 +41,6 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeEarlyTailDuplicatePass(Registry);
   initializeExpandLargeDivRemLegacyPassPass(Registry);
   initializeExpandLargeFpConvertLegacyPassPass(Registry);
-  initializeExpandMemCmpLegacyPassPass(Registry);
   initializeExpandPostRAPass(Registry);
   initializeFEntryInserterPass(Registry);
   initializeFinalizeISelPass(Registry);

llvm/lib/CodeGen/TargetPassConfig.cpp

@@ -108,9 +108,6 @@ static cl::opt<bool> EnableImplicitNullChecks(
     "enable-implicit-null-checks",
     cl::desc("Fold null checks into faulting memory operations"),
     cl::init(false), cl::Hidden);
-static cl::opt<bool> DisableMergeICmps("disable-mergeicmps",
-    cl::desc("Disable MergeICmps Pass"),
-    cl::init(false), cl::Hidden);
 static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden,
     cl::desc("Print LLVM IR produced by the loop-reduce pass"));
 static cl::opt<bool>
@@ -487,7 +484,6 @@ CGPassBuilderOption llvm::getCGPassBuilderOption() {
   SET_BOOLEAN_OPTION(EnableImplicitNullChecks)
   SET_BOOLEAN_OPTION(EnableMachineOutliner)
   SET_BOOLEAN_OPTION(MISchedPostRA)
-  SET_BOOLEAN_OPTION(DisableMergeICmps)
   SET_BOOLEAN_OPTION(DisableLSR)
   SET_BOOLEAN_OPTION(DisableConstantHoisting)
   SET_BOOLEAN_OPTION(DisableCGP)
@@ -827,14 +823,6 @@ void TargetPassConfig::addIRPasses() {
         addPass(createPrintFunctionPass(dbgs(),
                                         "\n\n*** Code after LSR ***\n"));
     }
-
-    // The MergeICmpsPass tries to create memcmp calls by grouping sequences of
-    // loads and compares. ExpandMemCmpPass then tries to expand those calls
-    // into optimally-sized loads and compares. The transforms are enabled by a
-    // target lowering hook.
-    if (!DisableMergeICmps)
-      addPass(createMergeICmpsLegacyPass());
-    addPass(createExpandMemCmpLegacyPass());
   }
 
   // Run GC lowering passes for builtin collectors

llvm/lib/Passes/PassBuilder.cpp

@@ -80,7 +80,6 @@
 #include "llvm/CodeGen/DwarfEHPrepare.h"
 #include "llvm/CodeGen/ExpandLargeDivRem.h"
 #include "llvm/CodeGen/ExpandLargeFpConvert.h"
-#include "llvm/CodeGen/ExpandMemCmp.h"
 #include "llvm/CodeGen/FreeMachineFunction.h"
 #include "llvm/CodeGen/GCMetadata.h"
 #include "llvm/CodeGen/GlobalMerge.h"
@@ -192,6 +191,7 @@
 #include "llvm/Transforms/Scalar/DeadStoreElimination.h"
 #include "llvm/Transforms/Scalar/DivRemPairs.h"
 #include "llvm/Transforms/Scalar/EarlyCSE.h"
+#include "llvm/Transforms/Scalar/ExpandMemCmp.h"
 #include "llvm/Transforms/Scalar/FlattenCFG.h"
 #include "llvm/Transforms/Scalar/Float2Int.h"
 #include "llvm/Transforms/Scalar/GVN.h"

llvm/lib/Passes/PassBuilderPipelines.cpp

@@ -87,6 +87,7 @@
 #include "llvm/Transforms/Scalar/DeadStoreElimination.h"
 #include "llvm/Transforms/Scalar/DivRemPairs.h"
 #include "llvm/Transforms/Scalar/EarlyCSE.h"
+#include "llvm/Transforms/Scalar/ExpandMemCmp.h"
 #include "llvm/Transforms/Scalar/Float2Int.h"
 #include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/Transforms/Scalar/IndVarSimplify.h"
@@ -113,6 +114,7 @@
 #include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
 #include "llvm/Transforms/Scalar/LowerMatrixIntrinsics.h"
 #include "llvm/Transforms/Scalar/MemCpyOptimizer.h"
+#include "llvm/Transforms/Scalar/MergeICmps.h"
 #include "llvm/Transforms/Scalar/MergedLoadStoreMotion.h"
 #include "llvm/Transforms/Scalar/NewGVN.h"
 #include "llvm/Transforms/Scalar/Reassociate.h"
@@ -1457,6 +1459,11 @@ PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
   // flattening of blocks.
   OptimizePM.addPass(DivRemPairsPass());
 
+  // Detect and convert memcmp like idioms to the call then expand them if
+  // profitable
+  OptimizePM.addPass(MergeICmpsPass());
+  OptimizePM.addPass(ExpandMemCmpPass());
+
   // Try to annotate calls that were created during optimization.
   OptimizePM.addPass(TailCallElimPass());
 
@@ -1979,6 +1986,11 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
   // flattening of blocks.
   LateFPM.addPass(DivRemPairsPass());
 
+  // Detect and convert memcmp like idioms to the call then expand them if
+  // profitable
+  LateFPM.addPass(MergeICmpsPass());
+  LateFPM.addPass(ExpandMemCmpPass());
+
   // Delete basic blocks, which optimization passes may have killed.
   LateFPM.addPass(SimplifyCFGPass(
       SimplifyCFGOptions().convertSwitchRangeToICmp(true).hoistCommonInsts(

llvm/lib/Passes/PassRegistry.def

@@ -328,7 +328,6 @@ FUNCTION_PASS("dse", DSEPass())
 FUNCTION_PASS("dwarf-eh-prepare", DwarfEHPreparePass(TM))
 FUNCTION_PASS("expand-large-div-rem", ExpandLargeDivRemPass(TM))
 FUNCTION_PASS("expand-large-fp-convert", ExpandLargeFpConvertPass(TM))
-FUNCTION_PASS("expand-memcmp", ExpandMemCmpPass(TM))
 FUNCTION_PASS("fix-irreducible", FixIrreduciblePass())
 FUNCTION_PASS("flatten-cfg", FlattenCFGPass())
 FUNCTION_PASS("float2int", Float2IntPass())
@@ -374,6 +373,7 @@ FUNCTION_PASS("mem2reg", PromotePass())
 FUNCTION_PASS("memcpyopt", MemCpyOptPass())
 FUNCTION_PASS("memprof", MemProfilerPass())
 FUNCTION_PASS("mergeicmps", MergeICmpsPass())
+FUNCTION_PASS("expand-memcmp", ExpandMemCmpPass())
 FUNCTION_PASS("mergereturn", UnifyFunctionExitNodesPass())
 FUNCTION_PASS("move-auto-init", MoveAutoInitPass())
 FUNCTION_PASS("nary-reassociate", NaryReassociatePass())

llvm/lib/Transforms/Scalar/CMakeLists.txt

@@ -11,6 +11,7 @@ add_llvm_component_library(LLVMScalarOpts
   DeadStoreElimination.cpp
   DFAJumpThreading.cpp
   DivRemPairs.cpp
+  ExpandMemCmp.cpp
   EarlyCSE.cpp
   FlattenCFGPass.cpp
   Float2Int.cpp