[llvm] ad8f6b4 - DAG: Avoid some libcall string name comparisons (#166321)

[via llvm-commits]

Author: Matt Arsenault
Date: 2025-11-05T07:09:02-08:00
New Revision: ad8f6b44be142eb943942f7760e520a36d237d48

URL: https://github.com/llvm/llvm-project/commit/ad8f6b44be142eb943942f7760e520a36d237d48
DIFF: https://github.com/llvm/llvm-project/commit/ad8f6b44be142eb943942f7760e520a36d237d48.diff

LOG: DAG: Avoid some libcall string name comparisons (#166321)

Move to the libcall impl based functions.

Added: 
    

Modified: 
    llvm/include/llvm/CodeGen/TargetLowering.h
    llvm/include/llvm/IR/RuntimeLibcalls.h
    llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
    llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
    llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/CodeGen/TargetLowering.h b/llvm/include/llvm/CodeGen/TargetLowering.h
index 78f63b4406eb0..b229659415d55 100644
--- a/llvm/include/llvm/CodeGen/TargetLowering.h
+++ b/llvm/include/llvm/CodeGen/TargetLowering.h
@@ -3620,10 +3620,7 @@ class LLVM_ABI TargetLoweringBase {
     return RTLIB::RuntimeLibcallsInfo::getLibcallImplName(Call);
   }
 
-  const char *getMemcpyName() const {
-    // FIXME: Return StringRef
-    return Libcalls.getMemcpyName().data();
-  }
+  RTLIB::LibcallImpl getMemcpyImpl() const { return Libcalls.getMemcpyImpl(); }
 
   /// Check if this is valid libcall for the current module, otherwise
   /// RTLIB::Unsupported.

diff  --git a/llvm/include/llvm/IR/RuntimeLibcalls.h b/llvm/include/llvm/IR/RuntimeLibcalls.h
index ab14ed44fed52..bae760b3f981d 100644
--- a/llvm/include/llvm/IR/RuntimeLibcalls.h
+++ b/llvm/include/llvm/IR/RuntimeLibcalls.h
@@ -134,13 +134,13 @@ struct RuntimeLibcallsInfo {
 
   /// Return a function name compatible with RTLIB::MEMCPY, or nullptr if fully
   /// unsupported.
-  StringRef getMemcpyName() const {
+  RTLIB::LibcallImpl getMemcpyImpl() const {
     RTLIB::LibcallImpl Memcpy = getLibcallImpl(RTLIB::MEMCPY);
     if (Memcpy != RTLIB::Unsupported)
-      return getLibcallImplName(Memcpy);
+      return Memcpy;
 
     // Fallback to memmove if memcpy isn't available.
-    return getLibcallName(RTLIB::MEMMOVE);
+    return getLibcallImpl(RTLIB::MEMMOVE);
   }
 
   bool isAvailable(RTLIB::LibcallImpl Impl) const {

diff  --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 52c43a4ac4a04..d02f097fef829 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -776,7 +776,7 @@ llvm::createMemLibcall(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI,
     break;
   case TargetOpcode::G_MEMCPY:
     RTLibcall = RTLIB::MEMCPY;
-    Name = TLI.getMemcpyName();
+    Name = TLI.getLibcallImplName(TLI.getMemcpyImpl()).data();
     Args[0].Flags[0].setReturned();
     break;
   case TargetOpcode::G_MEMMOVE:

diff  --git a/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp b/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
index 620d3d3d02daa..d738dc4eea36d 100644
--- a/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
+++ b/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
@@ -244,7 +244,7 @@ static bool canEmitMemcpy(const TargetMachine *TM, Function *F) {
   if (!TM)
     return true;
   const TargetLowering *TLI = TM->getSubtargetImpl(*F)->getTargetLowering();
-  return TLI->getMemcpyName() != nullptr;
+  return TLI->getMemcpyImpl() != RTLIB::Unsupported;
 }
 
 // Return a value appropriate for use with the memset_pattern16 libcall, if

diff  --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 379242ec5a157..ff6a7b2cf5462 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -9257,21 +9257,22 @@ SDValue SelectionDAG::getMemcpy(
   // FIXME: pass in SDLoc
   TargetLowering::CallLoweringInfo CLI(*this);
   bool IsTailCall = false;
-  const char *MemCpyName = TLI->getMemcpyName();
+  RTLIB::LibcallImpl MemCpyImpl = TLI->getMemcpyImpl();
 
   if (OverrideTailCall.has_value()) {
     IsTailCall = *OverrideTailCall;
   } else {
-    bool LowersToMemcpy = StringRef(MemCpyName) == StringRef("memcpy");
+    bool LowersToMemcpy = MemCpyImpl == RTLIB::impl_memcpy;
     IsTailCall = isInTailCallPositionWrapper(CI, this, LowersToMemcpy);
   }
 
   CLI.setDebugLoc(dl)
       .setChain(Chain)
       .setLibCallee(
-          TLI->getLibcallCallingConv(RTLIB::MEMCPY),
+          TLI->getLibcallImplCallingConv(MemCpyImpl),
           Dst.getValueType().getTypeForEVT(*getContext()),
-          getExternalSymbol(MemCpyName, TLI->getPointerTy(getDataLayout())),
+          getExternalSymbol(TLI->getLibcallImplName(MemCpyImpl).data(),
+                            TLI->getPointerTy(getDataLayout())),
           std::move(Args))
       .setDiscardResult()
       .setTailCall(IsTailCall);
@@ -9361,22 +9362,24 @@ SDValue SelectionDAG::getMemmove(SDValue Chain, const SDLoc &dl, SDValue Dst,
   // FIXME:  pass in SDLoc
   TargetLowering::CallLoweringInfo CLI(*this);
 
+  RTLIB::LibcallImpl MemmoveImpl = TLI->getLibcallImpl(RTLIB::MEMMOVE);
+
   bool IsTailCall = false;
   if (OverrideTailCall.has_value()) {
     IsTailCall = *OverrideTailCall;
   } else {
-    bool LowersToMemmove =
-        TLI->getLibcallName(RTLIB::MEMMOVE) == StringRef("memmove");
+    bool LowersToMemmove = MemmoveImpl == RTLIB::impl_memmove;
     IsTailCall = isInTailCallPositionWrapper(CI, this, LowersToMemmove);
   }
 
   CLI.setDebugLoc(dl)
       .setChain(Chain)
-      .setLibCallee(TLI->getLibcallCallingConv(RTLIB::MEMMOVE),
-                    Dst.getValueType().getTypeForEVT(*getContext()),
-                    getExternalSymbol(TLI->getLibcallName(RTLIB::MEMMOVE),
-                                      TLI->getPointerTy(getDataLayout())),
-                    std::move(Args))
+      .setLibCallee(
+          TLI->getLibcallImplCallingConv(MemmoveImpl),
+          Dst.getValueType().getTypeForEVT(*getContext()),
+          getExternalSymbol(TLI->getLibcallImplName(MemmoveImpl).data(),
+                            TLI->getPointerTy(getDataLayout())),
+          std::move(Args))
       .setDiscardResult()
       .setTailCall(IsTailCall);
 
@@ -9492,8 +9495,10 @@ SDValue SelectionDAG::getMemset(SDValue Chain, const SDLoc &dl, SDValue Dst,
                                        TLI->getPointerTy(DL)),
                      std::move(Args));
   }
-  bool LowersToMemset =
-      TLI->getLibcallName(RTLIB::MEMSET) == StringRef("memset");
+
+  RTLIB::LibcallImpl MemsetImpl = TLI->getLibcallImpl(RTLIB::MEMSET);
+  bool LowersToMemset = MemsetImpl == RTLIB::impl_memset;
+
   // If we're going to use bzero, make sure not to tail call unless the
   // subsequent return doesn't need a value, as bzero doesn't return the first
   // arg unlike memset.