diff --git a/compiler-rt/lib/profile/InstrProfiling.c b/compiler-rt/lib/profile/InstrProfiling.c
index c897052d8c48..936b8def38cb 100644
--- a/compiler-rt/lib/profile/InstrProfiling.c
+++ b/compiler-rt/lib/profile/InstrProfiling.c
@@ -8,6 +8,7 @@
 \*===----------------------------------------------------------------------===*/
 
 #include "InstrProfiling.h"
+#include <string.h>
 
 /* TODO: void __llvm_pgo_get_size_for_buffer(void);  */
 
@@ -34,3 +35,10 @@ void __llvm_pgo_write_buffer(FILE *OutputFile) {
        I != E; ++I)
     writeFunction(OutputFile, I);
 }
+
+void __llvm_pgo_reset_counters(void) {
+  uint64_t *I = __llvm_pgo_counters_begin();
+  uint64_t *E = __llvm_pgo_counters_end();
+
+  memset(I, 0, sizeof(uint64_t)*(E - I));
+}
diff --git a/compiler-rt/lib/profile/InstrProfiling.h b/compiler-rt/lib/profile/InstrProfiling.h
index a3e86ca557c5..9a659c04a64e 100644
--- a/compiler-rt/lib/profile/InstrProfiling.h
+++ b/compiler-rt/lib/profile/InstrProfiling.h
@@ -37,7 +37,7 @@ typedef struct __llvm_pgo_data {
   const uint32_t NumCounters;
   const uint64_t FuncHash;
   const char *const Name;
-  const uint64_t *const Counters;
+  uint64_t *const Counters;
 } __llvm_pgo_data;
 
 /* TODO: void __llvm_pgo_get_size_for_buffer(void);  */
@@ -55,5 +55,5 @@ const __llvm_pgo_data *__llvm_pgo_data_begin();
 const __llvm_pgo_data *__llvm_pgo_data_end();
 const char *__llvm_pgo_names_begin();
 const char *__llvm_pgo_names_end();
-const uint64_t *__llvm_pgo_counters_begin();
-const uint64_t *__llvm_pgo_counters_end();
+uint64_t *__llvm_pgo_counters_begin();
+uint64_t *__llvm_pgo_counters_end();
diff --git a/compiler-rt/lib/profile/InstrProfilingPlatformDarwin.c b/compiler-rt/lib/profile/InstrProfilingPlatformDarwin.c
index de388ee5ebda..decd6b09bb3e 100644
--- a/compiler-rt/lib/profile/InstrProfilingPlatformDarwin.c
+++ b/compiler-rt/lib/profile/InstrProfilingPlatformDarwin.c
@@ -21,5 +21,5 @@ const __llvm_pgo_data *__llvm_pgo_data_begin() { return &DataStart; }
 const __llvm_pgo_data *__llvm_pgo_data_end()   { return &DataEnd; }
 const char *__llvm_pgo_names_begin() { return &NamesStart; }
 const char *__llvm_pgo_names_end()   { return &NamesEnd; }
-const uint64_t *__llvm_pgo_counters_begin() { return &CountersStart; }
-const uint64_t *__llvm_pgo_counters_end()   { return &CountersEnd; }
+uint64_t *__llvm_pgo_counters_begin() { return &CountersStart; }
+uint64_t *__llvm_pgo_counters_end()   { return &CountersEnd; }
diff --git a/compiler-rt/lib/profile/InstrProfilingPlatformOther.c b/compiler-rt/lib/profile/InstrProfilingPlatformOther.c
index d39f39f37183..dbd7d06ed1f3 100644
--- a/compiler-rt/lib/profile/InstrProfilingPlatformOther.c
+++ b/compiler-rt/lib/profile/InstrProfilingPlatformOther.c
@@ -13,8 +13,8 @@ static const __llvm_pgo_data *DataFirst = NULL;
 static const __llvm_pgo_data *DataLast = NULL;
 static const char *NamesFirst = NULL;
 static const char *NamesLast = NULL;
-static const uint64_t *CountersFirst = NULL;
-static const uint64_t *CountersLast = NULL;
+static uint64_t *CountersFirst = NULL;
+static uint64_t *CountersLast = NULL;
 
 /*!
  * \brief Register an instrumented function.
@@ -55,5 +55,5 @@ const __llvm_pgo_data *__llvm_pgo_data_begin() { return DataFirst; }
 const __llvm_pgo_data *__llvm_pgo_data_end() { return DataLast; }
 const char *__llvm_pgo_names_begin() { return NamesFirst; }
 const char *__llvm_pgo_names_end() { return NamesLast; }
-const uint64_t *__llvm_pgo_counters_begin() { return CountersFirst; }
-const uint64_t *__llvm_pgo_counters_end() { return CountersLast; }
+uint64_t *__llvm_pgo_counters_begin() { return CountersFirst; }
+uint64_t *__llvm_pgo_counters_end() { return CountersLast; }