Index: include/sanitizer/coverage_interface.h
===================================================================
--- include/sanitizer/coverage_interface.h
+++ include/sanitizer/coverage_interface.h
@@ -23,6 +23,11 @@
   void __sanitizer_cov_init();
   // Record and dump coverage info.
   void __sanitizer_cov_dump();
+
+  //  Dump collected coverage info. Sorts pcs by module into individual
+  //  .sancov files.
+  void __sanitizer_dump_coverage(const uintptr_t *pcs, uintptr_t len);
+
   // Open <name>.sancov.packed in the coverage directory and return the file
   // descriptor. Returns -1 on failure, or if coverage dumping is disabled.
   // This is intended for use by sandboxing code.
Index: lib/sanitizer_common/CMakeLists.txt
===================================================================
--- lib/sanitizer_common/CMakeLists.txt
+++ lib/sanitizer_common/CMakeLists.txt
@@ -53,6 +53,7 @@
 set(SANITIZER_LIBCDEP_SOURCES
   sanitizer_common_libcdep.cc
   sanitizer_coverage_libcdep.cc
+  sanitizer_coverage_libcdep_new.cc
   sanitizer_coverage_mapping_libcdep.cc
   sanitizer_linux_libcdep.cc
   sanitizer_posix_libcdep.cc
Index: lib/sanitizer_common/sanitizer_addrhashmap.h
===================================================================
--- lib/sanitizer_common/sanitizer_addrhashmap.h
+++ lib/sanitizer_common/sanitizer_addrhashmap.h
@@ -73,6 +73,8 @@
 
     ~Handle();
     T *operator->();
+    T &operator*();
+    const T &operator*() const;
     bool created() const;
     bool exists() const;
 
@@ -136,6 +138,16 @@
   return &cell_->val;
 }
 
+template <typename T, uptr kSize>
+const T &AddrHashMap<T, kSize>::Handle::operator*() const {
+  return cell_->val;
+}
+
+template <typename T, uptr kSize>
+T &AddrHashMap<T, kSize>::Handle::operator*() {
+  return cell_->val;
+}
+
 template<typename T, uptr kSize>
 bool AddrHashMap<T, kSize>::Handle::created() const {
   return created_;
Index: lib/sanitizer_common/sanitizer_coverage_libcdep_new.cc
===================================================================
--- /dev/null
+++ lib/sanitizer_common/sanitizer_coverage_libcdep_new.cc
@@ -0,0 +1,128 @@
+//===-- sanitizer_coverage.cc ---------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Sanitizer Coverage.
+
+#include "sanitizer_addrhashmap.h"
+#include "sanitizer_common.h"
+#include "sanitizer_symbolizer.h"
+
+using namespace __sanitizer;
+
+using AddressRange = LoadedModule::AddressRange;
+
+namespace {
+
+static const u64 Magic64 = 0xC0BFFFFFFFFFFF64ULL;
+static const u64 Magic32 = 0xC0BFFFFFFFFFFF32ULL;
+static const u64 Magic = SANITIZER_WORDSIZE == 64 ? Magic64 : Magic32;
+
+struct ModuleAndRange {
+  const LoadedModule* module;
+  const AddressRange* range;
+};
+
+struct CovFile {
+  CovFile() : fd(-1), num_offsets(0), file_path(0) {}
+
+  fd_t fd;
+  uptr num_offsets;
+  char* file_path;
+};
+
+};  // namespace
+
+static fd_t OpenFile(const char* path) {
+  error_t err;
+  fd_t fd = OpenFile(path, WrOnly, &err);
+  if (fd == kInvalidFd)
+    Report("SanitizerCoverage: failed to open %s for writing (reason: %d)\n",
+           path, err);
+  return fd;
+}
+
+static void GetCoverageFilename(char* path, const char* name,
+                                const char* extension) {
+  CHECK(name);
+  internal_snprintf(path, kMaxPathLength, "%s/%s.%zd.%s",
+                    common_flags()->coverage_dir, name, internal_getpid(),
+                    extension);
+}
+
+static void SanitizerDumpCoverage(const uptr* pcs, uptr len) {
+  auto symbolizer = Symbolizer::GetOrInit();
+  if (!symbolizer) return;
+
+  InternalMmapVector<fd_t> open_files(0);
+  using CovFilesMap = AddrHashMap<CovFile, 17>;
+  CovFilesMap cov_files;
+
+  ListOfModules modules;
+  modules.init();
+  InternalMmapVector<ModuleAndRange> ranges(modules.size());
+  for (const LoadedModule& module : modules) {
+    for (const AddressRange& r : module.ranges()) {
+      ranges.push_back(ModuleAndRange {&module, &r});
+    }
+  }
+  InternalSort(&ranges, ranges.size(),
+               [](const ModuleAndRange& m1, const ModuleAndRange& m2) {
+                 return m1.range->end < m2.range->end;
+               });
+
+  for (uptr i = 0; i < len; ++i) {
+    const uptr pc = pcs[i];
+    if (!pc)
+      continue;
+
+    uptr idx = InternalBinarySearch(
+        ranges, 0, ranges.size(), pc,
+        [](const ModuleAndRange& m, uptr pc) { return pc >= m.range->end; });
+    if (idx >= ranges.size()) {
+      Printf("ERROR: bad pc %x\n", pc);
+      continue;
+    }
+
+    const ModuleAndRange& module_and_range = ranges[idx];
+    auto module = module_and_range.module;
+    auto range = module_and_range.range;
+
+    if (range->beg > pc || range->end <= pc) {
+      Printf("ERROR: bad pc %x\n", pc);
+      continue;
+    }
+
+    CovFilesMap::Handle h(&cov_files, (uptr)&module);
+    if (h.created()) {
+      h->file_path = static_cast<char*>(InternalAlloc(kMaxPathLength));
+      GetCoverageFilename(h->file_path, StripModuleName(module->full_name()),
+                          "sancov");
+      h->fd = OpenFile(h->file_path);
+      WriteToFile(h->fd, &Magic, sizeof(Magic));
+    }
+
+    const uptr offset = pc - module->base_address();
+    h->num_offsets++;
+    WriteToFile(h->fd, &offset, sizeof(offset));
+  }
+
+  for (const LoadedModule& module : modules) {
+    CovFilesMap::Handle h(&cov_files, (uptr)&module);
+    if (h.created()) continue;
+    CloseFile(h->fd);
+    VReport(1, " CovDump: %s: %zd PCs written\n", h->file_path, h->num_offsets);
+    InternalFree(h->file_path);
+  }
+}
+
+// clang-format off
+SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_coverage(  // NOLINT
+    const uptr* pcs, uptr len) {
+  return SanitizerDumpCoverage(pcs, len);
+}
+// clang-format on
Index: lib/sanitizer_common/sanitizer_interface_internal.h
===================================================================
--- lib/sanitizer_common/sanitizer_interface_internal.h
+++ lib/sanitizer_common/sanitizer_interface_internal.h
@@ -46,8 +46,11 @@
   SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
   void __sanitizer_report_error_summary(const char *error_summary);
 
-  SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump();
   SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_init();
+  SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump();
+  SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_coverage(
+      const __sanitizer::uptr *pcs, const __sanitizer::uptr len);
+
   SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov(__sanitizer::u32 *guard);
   SANITIZER_INTERFACE_ATTRIBUTE
   void __sanitizer_annotate_contiguous_container(const void *beg,