[llvm] [CoroFrame][NFC] Remove code duplication in insertSpills (PR #177367)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Felipe de Azevedo Piovezan (felipepiovezan)

<details>
<summary>Changes</summary>

This commit removes a duplicated loop looking through loads when finding dbg records associated with a Value.

---
Full diff: https://github.com/llvm/llvm-project/pull/177367.diff


1 Files Affected:

- (modified) llvm/lib/Transforms/Coroutines/CoroFrame.cpp (+34-34) 


``````````diff
diff --git a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
index 539f5178245fd..37ec45ad790c2 100644
--- a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
@@ -1056,6 +1056,36 @@ static Value *createGEPToFramePointer(const FrameDataInfo &FrameData,
   return GEP;
 }
 
+/// Find dbg.declare or dbg.declare_value records referencing `Def`. If none are
+/// found, walk up the load chain to find one.
+template <DbgVariableRecord::LocationType record_type>
+static TinyPtrVector<DbgVariableRecord *>
+findDbgRecordsThroughLoads(Function &F, Value *Def) {
+  if (!F.getSubprogram())
+    return {};
+
+  static_assert(record_type == DbgVariableRecord::LocationType::Declare ||
+                record_type == DbgVariableRecord::LocationType::DeclareValue);
+  constexpr auto FindFunc =
+      record_type == DbgVariableRecord::LocationType::Declare
+          ? findDVRDeclares
+          : findDVRDeclareValues;
+
+  TinyPtrVector<DbgVariableRecord *> Records = FindFunc(Def);
+  Value *CurDef = Def;
+  while (Records.empty() && isa<LoadInst>(CurDef)) {
+    auto *LdInst = cast<LoadInst>(CurDef);
+    if (!LdInst->getType()->isPointerTy())
+      break;
+    CurDef = LdInst->getPointerOperand();
+    if (!isa<AllocaInst, LoadInst>(CurDef))
+      break;
+    Records = FindFunc(CurDef);
+  }
+
+  return Records;
+}
+
 // Replace all alloca and SSA values that are accessed across suspend points
 // with GetElementPointer from coroutine frame + loads and stores. Create an
 // AllocaSpillBB that will become the new entry block for the resume parts of
@@ -1114,23 +1144,8 @@ static void insertSpills(const FrameDataInfo &FrameData, coro::Shape &Shape) {
               SpillAlignment, E.first->getName() + Twine(".reload"));
         }
 
-        TinyPtrVector<DbgVariableRecord *> DVRs = findDVRDeclares(Def);
-        // Try best to find dbg.declare. If the spill is a temp, there may not
-        // be a direct dbg.declare. Walk up the load chain to find one from an
-        // alias.
-        if (F->getSubprogram()) {
-          auto *CurDef = Def;
-          while (DVRs.empty() && isa<LoadInst>(CurDef)) {
-            auto *LdInst = cast<LoadInst>(CurDef);
-            // Only consider ptr to ptr same type load.
-            if (LdInst->getPointerOperandType() != LdInst->getType())
-              break;
-            CurDef = LdInst->getPointerOperand();
-            if (!isa<AllocaInst, LoadInst>(CurDef))
-              break;
-            DVRs = findDVRDeclares(CurDef);
-          }
-        }
+        TinyPtrVector<DbgVariableRecord *> DVRs = findDbgRecordsThroughLoads<
+            DbgVariableRecord::LocationType::Declare>(*F, Def);
 
         auto SalvageOne = [&](DbgVariableRecord *DDI) {
           // This dbg.declare is preserved for all coro-split function
@@ -1150,23 +1165,8 @@ static void insertSpills(const FrameDataInfo &FrameData, coro::Shape &Shape) {
       }
 
       TinyPtrVector<DbgVariableRecord *> DVRDeclareValues =
-          findDVRDeclareValues(Def);
-      // Try best to find dbg.declare_value. If the spill is a temp, there may
-      // not be a direct dbg.declare_value. Walk up the load chain to find one
-      // from an alias.
-      if (F->getSubprogram()) {
-        auto *CurDef = Def;
-        while (DVRDeclareValues.empty() && isa<LoadInst>(CurDef)) {
-          auto *LdInst = cast<LoadInst>(CurDef);
-          // Only consider ptr to ptr same type load.
-          if (LdInst->getPointerOperandType() != LdInst->getType())
-            break;
-          CurDef = LdInst->getPointerOperand();
-          if (!isa<AllocaInst, LoadInst>(CurDef))
-            break;
-          DVRDeclareValues = findDVRDeclareValues(CurDef);
-        }
-      }
+          findDbgRecordsThroughLoads<
+              DbgVariableRecord::LocationType::DeclareValue>(*F, Def);
 
       auto SalvageOneCoro = [&](auto *DDI) {
         // This dbg.declare_value is preserved for all coro-split function

``````````

</details>


https://github.com/llvm/llvm-project/pull/177367