[llvm] [ctx_profile] Profile reader and writer (PR #91859)

[Snehasish Kumar via llvm-commits]

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@@ -0,0 +1,167 @@
+//===- PGOCtxProfReader.cpp - Contextual Instrumentation profile reader ---===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Read a contextual profile into a datastructure suitable for maintenance
+// throughout IPO
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ProfileData/PGOCtxProfReader.h"
+#include "llvm/Bitstream/BitCodeEnums.h"
+#include "llvm/Bitstream/BitstreamReader.h"
+#include "llvm/ProfileData/InstrProf.h"
+#include "llvm/ProfileData/PGOCtxProfWriter.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/Error.h"
+
+using namespace llvm;
+
+// FIXME(#92054) - these Error handling macros are (re-)invented in a few
+// places.
+#define EXPECT_OR_RET(LHS, RHS)                                                \
+  auto LHS = RHS;                                                              \
+  if (!LHS)                                                                    \
+    return LHS.takeError();
+
+#define RET_ON_ERR(EXPR)                                                       \
+  if (auto Err = (EXPR))                                                       \
+    return Err;
+
+Expected<PGOContextualProfile &>
+PGOContextualProfile::getOrEmplace(uint32_t Index, GlobalValue::GUID G,
+                                   SmallVectorImpl<uint64_t> &&Counters) {
+  auto I = Callsites[Index].insert(
+      {G, PGOContextualProfile(G, std::move(Counters))});
+  if (!I.second)
+    return make_error<StringError>(llvm::errc::invalid_argument,
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snehasish wrote:

Can this be `instrprof_error::invalid_prof`?

https://github.com/llvm/llvm-project/pull/91859