[lld] [lld][InstrProf] Profile guided function order (PR #96268)

[Scott Todd via llvm-commits]

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@@ -0,0 +1,413 @@
+//===- BPSectionOrderer.cpp--------------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "BPSectionOrderer.h"
+#include "InputSection.h"
+#include "lld/Common/ErrorHandler.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ProfileData/InstrProfReader.h"
+#include "llvm/Support/BalancedPartitioning.h"
+#include "llvm/Support/TimeProfiler.h"
+#include "llvm/Support/VirtualFileSystem.h"
+#include "llvm/Support/xxhash.h"
+
+#define DEBUG_TYPE "bp-section-orderer"
+using namespace llvm;
+using namespace lld::macho;
+
+/// Symbols can be appended with "(.__uniq.xxxx)?.llvm.yyyy" where "xxxx" and
+/// "yyyy" are numbers that could change between builds. We need to use the root
+/// symbol name before this suffix so these symbols can be matched with profiles
+/// which may have different suffixes.
+static StringRef getRootSymbol(StringRef Name) {
+  auto [P0, S0] = Name.rsplit(".llvm.");
+  auto [P1, S1] = P0.rsplit(".__uniq.");
+  return P1;
+}
+
+static uint64_t getRelocHash(StringRef kind, uint64_t sectionIdx,
+                             uint64_t offset, uint64_t addend) {
+  return xxHash64((kind + ": " + Twine::utohexstr(sectionIdx) + " + " +
+                   Twine::utohexstr(offset) + " + " + Twine::utohexstr(addend))
+                      .str());
+}
+
+static uint64_t
+getRelocHash(const Reloc &reloc,
+             const DenseMap<const InputSection *, uint64_t> &sectionToIdx) {
+  auto *isec = reloc.getReferentInputSection();
+  std::optional<uint64_t> sectionIdx;
+  auto sectionIdxIt = sectionToIdx.find(isec);
+  if (sectionIdxIt != sectionToIdx.end())
+    sectionIdx = sectionIdxIt->getSecond();
+  std::string kind;
+  if (isec)
+    kind = ("Section " + Twine(isec->kind())).str();
+  if (auto *sym = reloc.referent.dyn_cast<Symbol *>()) {
+    kind += (" Symbol " + Twine(sym->kind())).str();
----------------
ScottTodd wrote:

Fix: https://github.com/llvm/llvm-project/pull/100627

https://github.com/llvm/llvm-project/pull/96268