[llvm] [NFC] Refactor the SelectionDAG::getMemcmp etc with a existing helper function getRuntimeCallSDValueHelper (PR #184200)

[zhijian lin via llvm-commits]

https://github.com/diggerlin updated https://github.com/llvm/llvm-project/pull/184200

>From c7c9130e38c3966b2a79a6ce8f62d1800e2c4271 Mon Sep 17 00:00:00 2001
From: zhijian <zhijian at ca.ibm.com>
Date: Fri, 27 Feb 2026 15:39:24 +0000
Subject: [PATCH 1/2] refactor the code using a helper function

---
 .../lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 61 ++-----------------
 1 file changed, 6 insertions(+), 55 deletions(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 4a2bd811b5214..f1a36b2bc2497 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -9406,84 +9406,35 @@ std::pair<SDValue, SDValue> SelectionDAG::getMemccpy(SDValue Chain,
 std::pair<SDValue, SDValue>
 SelectionDAG::getMemcmp(SDValue Chain, const SDLoc &dl, SDValue Mem0,
                         SDValue Mem1, SDValue Size, const CallInst *CI) {
-  RTLIB::LibcallImpl MemcmpImpl = Libcalls->getLibcallImpl(RTLIB::MEMCMP);
-  if (MemcmpImpl == RTLIB::Unsupported)
-    return {};
-
   PointerType *PT = PointerType::getUnqual(*getContext());
   TargetLowering::ArgListTy Args = {
       {Mem0, PT},
       {Mem1, PT},
       {Size, getDataLayout().getIntPtrType(*getContext())}};
-
-  TargetLowering::CallLoweringInfo CLI(*this);
-  bool IsTailCall =
-      isInTailCallPositionWrapper(CI, this, /*AllowReturnsFirstArg*/ true);
-
-  CLI.setDebugLoc(dl)
-      .setChain(Chain)
-      .setLibCallee(
-          Libcalls->getLibcallImplCallingConv(MemcmpImpl),
-          Type::getInt32Ty(*getContext()),
-          getExternalSymbol(MemcmpImpl, TLI->getPointerTy(getDataLayout())),
-          std::move(Args))
-      .setTailCall(IsTailCall);
-
-  return TLI->LowerCallTo(CLI);
+  return getRuntimeCallSDValueHelper(Chain, dl, std::move(Args), CI,
+                                     RTLIB::MEMCMP, this, TLI);
 }
 
 std::pair<SDValue, SDValue> SelectionDAG::getStrcpy(SDValue Chain,
                                                     const SDLoc &dl,
                                                     SDValue Dst, SDValue Src,
                                                     const CallInst *CI) {
-  RTLIB::LibcallImpl LCImpl = Libcalls->getLibcallImpl(RTLIB::STRCPY);
-  if (LCImpl == RTLIB::Unsupported)
-    return {};
-
   PointerType *PT = PointerType::getUnqual(*getContext());
   TargetLowering::ArgListTy Args = {{Dst, PT}, {Src, PT}};
-
-  TargetLowering::CallLoweringInfo CLI(*this);
-  bool IsTailCall =
-      isInTailCallPositionWrapper(CI, this, /*AllowReturnsFirstArg=*/true);
-
-  CLI.setDebugLoc(dl)
-      .setChain(Chain)
-      .setLibCallee(
-          Libcalls->getLibcallImplCallingConv(LCImpl), CI->getType(),
-          getExternalSymbol(LCImpl, TLI->getPointerTy(getDataLayout())),
-          std::move(Args))
-      .setTailCall(IsTailCall);
-
-  return TLI->LowerCallTo(CLI);
+  return getRuntimeCallSDValueHelper(Chain, dl, std::move(Args), CI,
+                                     RTLIB::STRCPY, this, TLI);
 }
 
 std::pair<SDValue, SDValue> SelectionDAG::getStrlen(SDValue Chain,
                                                     const SDLoc &dl,
                                                     SDValue Src,
                                                     const CallInst *CI) {
-  RTLIB::LibcallImpl StrlenImpl = Libcalls->getLibcallImpl(RTLIB::STRLEN);
-  if (StrlenImpl == RTLIB::Unsupported)
-    return {};
-
   // Emit a library call.
   TargetLowering::ArgListTy Args = {
       {Src, PointerType::getUnqual(*getContext())}};
-
+  return getRuntimeCallSDValueHelper(Chain, dl, std::move(Args), CI,
+                                     RTLIB::STRLEN, this, TLI);
   TargetLowering::CallLoweringInfo CLI(*this);
-  bool IsTailCall =
-      isInTailCallPositionWrapper(CI, this, /*AllowReturnsFirstArg*/ true);
-
-  CLI.setDebugLoc(dl)
-      .setChain(Chain)
-      .setLibCallee(Libcalls->getLibcallImplCallingConv(StrlenImpl),
-                    CI->getType(),
-                    getExternalSymbol(
-                        StrlenImpl, TLI->getProgramPointerTy(getDataLayout())),
-                    std::move(Args))
-      .setTailCall(IsTailCall);
-
-  return TLI->LowerCallTo(CLI);
 }
 
 SDValue SelectionDAG::getMemcpy(

>From 1c4f51395dc7e29472bfeacd308e5fed7c794df4 Mon Sep 17 00:00:00 2001
From: zhijian <zhijian at ca.ibm.com>
Date: Tue, 3 Mar 2026 14:58:31 +0000
Subject: [PATCH 2/2] delete dead code

---
 llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index f1a36b2bc2497..9eb70cb2d3e9a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -9434,7 +9434,6 @@ std::pair<SDValue, SDValue> SelectionDAG::getStrlen(SDValue Chain,
       {Src, PointerType::getUnqual(*getContext())}};
   return getRuntimeCallSDValueHelper(Chain, dl, std::move(Args), CI,
                                      RTLIB::STRLEN, this, TLI);
-  TargetLowering::CallLoweringInfo CLI(*this);
 }
 
 SDValue SelectionDAG::getMemcpy(