[llvm] [LLVM][DWARF] Make dwarf::getDebugNamesBucketCount return a pair. (PR #83047)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-binary-utilities

Author: None (cmtice)

<details>
<summary>Changes</summary>

llvm::dwarf::getDebugNamesBucketCount directly returns the bucket count, via return statement, but it also returns the hash count via a parameter. This changes the function to return them both as a std::pair, in the return statement. It also changes the name of the function to make it clear it returns both values.

---
Full diff: https://github.com/llvm/llvm-project/pull/83047.diff


2 Files Affected:

- (modified) llvm/include/llvm/BinaryFormat/Dwarf.h (+8-7) 
- (modified) llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp (+3-1) 


``````````diff
diff --git a/llvm/include/llvm/BinaryFormat/Dwarf.h b/llvm/include/llvm/BinaryFormat/Dwarf.h
index 44c0030251b37e..e2d79785162e37 100644
--- a/llvm/include/llvm/BinaryFormat/Dwarf.h
+++ b/llvm/include/llvm/BinaryFormat/Dwarf.h
@@ -616,20 +616,21 @@ enum AcceleratorTable {
 // Uniquify the string hashes and calculate the bucket count for the
 // DWARF v5 Accelerator Table. NOTE: This function effectively consumes the
 // 'hashes' input parameter.
-inline uint32_t getDebugNamesBucketCount(MutableArrayRef<uint32_t> hashes,
-                                         uint32_t &uniqueHashCount) {
-  uint32_t BucketCount = 0;
+inline std::pair<uint32_t, uint32_t> getDebugNamesBucketAndHashCount(
+    MutableArrayRef<uint32_t> hashes) {
+  uint32_t uniqueHashCount = 0;
+  uint32_t bucketCount = 0;
 
   sort(hashes);
   uniqueHashCount = llvm::unique(hashes) - hashes.begin();
   if (uniqueHashCount > 1024)
-    BucketCount = uniqueHashCount / 4;
+    bucketCount = uniqueHashCount / 4;
   else if (uniqueHashCount > 16)
-    BucketCount = uniqueHashCount / 2;
+    bucketCount = uniqueHashCount / 2;
   else
-    BucketCount = std::max<uint32_t>(uniqueHashCount, 1);
+    bucketCount = std::max<uint32_t>(uniqueHashCount, 1);
 
-  return BucketCount;
+  return {bucketCount, uniqueHashCount};
 }
 
 // Constants for the GNU pubnames/pubtypes extensions supporting gdb index.
diff --git a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
index 23fc9b2e0410e0..94e9d5e9cb77ce 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
@@ -38,7 +38,9 @@ void AccelTableBase::computeBucketCount() {
   for (const auto &E : Entries)
     Uniques.push_back(E.second.HashValue);
 
-  BucketCount = llvm::dwarf::getDebugNamesBucketCount(Uniques, UniqueHashCount);
+  auto counts = llvm::dwarf::getDebugNamesBucketAndHashCount(Uniques);
+  BucketCount = counts.first;
+  UniqueHashCount = counts.second;
 }
 
 void AccelTableBase::finalize(AsmPrinter *Asm, StringRef Prefix) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/83047