[memprof] Introduce memprof::LinearFrameId (NFC)

[kazutakahirata]

This patch introduces memprof::LinearFrameId, which is a frame version
of memprof::LinearCallStackId.

[llvmbot]

@llvm/pr-subscribers-pgo

Author: Kazu Hirata (kazutakahirata)

Changes

This patch introduces memprof::LinearFrameId, which is a frame version
of memprof::LinearCallStackId.

---

Full diff: https://github.com/llvm/llvm-project/pull/94057.diff

2 Files Affected:

• (modified) llvm/include/llvm/ProfileData/MemProf.h (+2)
• (modified) llvm/lib/ProfileData/InstrProfWriter.cpp (+6-4)

diff --git a/llvm/include/llvm/ProfileData/MemProf.h b/llvm/include/llvm/ProfileData/MemProf.h
index 2a7c853cade66..5b0d1c867b202 100644
--- a/llvm/include/llvm/ProfileData/MemProf.h
+++ b/llvm/include/llvm/ProfileData/MemProf.h
@@ -188,6 +188,8 @@ struct PortableMemInfoBlock {
 
 // A type representing the id generated by hashing the contents of the Frame.
 using FrameId = uint64_t;
+// A type representing the id to index into the frame array.
+using LinearFrameId = uint32_t;
 // Describes a call frame for a dynamic allocation context. The contents of
 // the frame are populated by symbolizing the stack depot call frame from the
 // compiler runtime.
diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
index 9b12922427779..e58e6b8acfc81 100644
--- a/llvm/lib/ProfileData/InstrProfWriter.cpp
+++ b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -491,11 +491,12 @@ static uint64_t writeMemProfFrames(
 
 // Serialize MemProfFrameData.  Return the mapping from FrameIds to their
 // indexes within the frame array.
-static llvm::DenseMap<memprof::FrameId, uint32_t> writeMemProfFrameArray(
+static llvm::DenseMap<memprof::FrameId, memprof::LinearFrameId>
+writeMemProfFrameArray(
     ProfOStream &OS,
     llvm::MapVector<memprof::FrameId, memprof::Frame> &MemProfFrameData) {
   // Mappings from FrameIds to array indexes.
-  llvm::DenseMap<memprof::FrameId, uint32_t> MemProfFrameIndexes;
+  llvm::DenseMap<memprof::FrameId, memprof::LinearFrameId> MemProfFrameIndexes;
 
   // Sort the FrameIDs for stability.
   std::vector<std::pair<memprof::FrameId, const memprof::Frame *>> FrameIdOrder;
@@ -541,7 +542,8 @@ writeMemProfCallStackArray(
     ProfOStream &OS,
     llvm::MapVector<memprof::CallStackId, llvm::SmallVector<memprof::FrameId>>
         &MemProfCallStackData,
-    llvm::DenseMap<memprof::FrameId, uint32_t> &MemProfFrameIndexes) {
+    llvm::DenseMap<memprof::FrameId, memprof::LinearFrameId>
+        &MemProfFrameIndexes) {
   llvm::DenseMap<memprof::CallStackId, memprof::LinearCallStackId>
       MemProfCallStackIndexes;
 
@@ -710,7 +712,7 @@ static Error writeMemProfV3(ProfOStream &OS,
     Schema = memprof::getFullSchema();
   writeMemProfSchema(OS, Schema);
 
-  llvm::DenseMap<memprof::FrameId, uint32_t> MemProfFrameIndexes =
+  llvm::DenseMap<memprof::FrameId, memprof::LinearFrameId> MemProfFrameIndexes =
       writeMemProfFrameArray(OS, MemProfData.FrameData);
 
   uint64_t CallStackPayloadOffset = OS.tell();