diff --git a/runtime/libprofile/BlockProfiling.c b/runtime/libprofile/BlockProfiling.c
new file mode 100644
index 00000000000..01b80a88e01
--- /dev/null
+++ b/runtime/libprofile/BlockProfiling.c
@@ -0,0 +1,43 @@
+/*===-- BlockProfiling.c - Support library for block profiling ------------===*\
+|*
+|*                     The LLVM Compiler Infrastructure
+|*
+|* This file was developed by the LLVM research group and is distributed under
+|* the University of Illinois Open Source License. See LICENSE.TXT for details.
+|* 
+|*===----------------------------------------------------------------------===*|
+|* 
+|* This file implements the call back routines for the block profiling
+|* instrumentation pass.  This should be used with the -insert-block-profiling
+|* LLVM pass.
+|*
+\*===----------------------------------------------------------------------===*/
+
+#include "Profiling.h"
+#include <stdlib.h>
+
+static unsigned *ArrayStart;
+static unsigned NumElements;
+
+/* BlockProfAtExitHandler - When the program exits, just write out the profiling
+ * data.
+ */
+static void BlockProfAtExitHandler() {
+  /* Note that if this were doing something more intellegent with the
+     instrumentation, that we could do some computation here to expand what we
+     collected into simple block profiles.  Since we directly count each block,
+  */
+  write_profiling_data(Block, ArrayStart, NumElements);
+}
+
+
+/* llvm_start_block_profiling - This is the main entry point of the block
+ * profiling library.  It is responsible for setting up the atexit handler.
+ */
+void llvm_start_block_profiling(int argc, const char **argv,
+                                unsigned *arrayStart, unsigned numElements) {
+  save_arguments(argc, argv);
+  ArrayStart = arrayStart;
+  NumElements = numElements;
+  atexit(BlockProfAtExitHandler);
+}
diff --git a/runtime/libprofile/CommonProfiling.c b/runtime/libprofile/CommonProfiling.c
new file mode 100644
index 00000000000..ea795b6989e
--- /dev/null
+++ b/runtime/libprofile/CommonProfiling.c
@@ -0,0 +1,82 @@
+/*===-- CommonProfiling.c - Profiling support library support -------------===*\
+|*
+|*                     The LLVM Compiler Infrastructure
+|*
+|* This file was developed by the LLVM research group and is distributed under
+|* the University of Illinois Open Source License. See LICENSE.TXT for details.
+|* 
+|*===----------------------------------------------------------------------===*|
+|* 
+|* This file implements functions used by the various different types of
+|* profiling implementations.
+|*
+\*===----------------------------------------------------------------------===*/
+
+#include "Profiling.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+static int SavedArgc = 0;
+static const char **SavedArgv = 0;
+
+/* save_arguments - Save argc and argv as passed into the program for the file
+ * we output.
+ */
+void save_arguments(int argc, const char **argv) {
+  if (SavedArgv) return;  /* This can be called multiple times */
+
+  /* FIXME: this should copy the arguments out of argv into a string of our own,
+   * because the program might modify the arguments!
+   */
+  SavedArgc = argc;
+  SavedArgv = argv;
+}
+
+
+
+
+/* write_profiling_data - Write a raw block of profiling counters out to the
+ * llvmprof.out file.  Note that we allow programs to be instrumented with
+ * multiple different kinds of instrumentation.  For this reason, this function
+ * may be called more than once.
+ */
+void write_profiling_data(enum ProfilingType PT, unsigned *Start,
+                          unsigned NumElements) {
+  static int OutFile = -1;
+  int PTy;
+  
+  /* If this is the first time this function is called, open the output file for
+   * appending, creating it if it does not already exist.
+   */
+  if (OutFile == -1) {
+    off_t Offset;
+    OutFile = open("llvmprof.out", O_CREAT | O_WRONLY | O_APPEND, 0666);
+    if (OutFile == -1) {
+      perror("LLVM profiling: while opening 'llvmprof.out'");
+      return;
+    }
+
+    /* Output the command line arguments to the file. */
+    {
+      const char *Args = "";
+      int PTy = Arguments;
+      int ArgLength = strlen(Args);
+      int Zeros = 0;
+      write(OutFile, &PTy, sizeof(int));
+      write(OutFile, &ArgLength, sizeof(int));
+      write(OutFile, Args, ArgLength);
+      /* Pad out to a multiple of four bytes */
+      if (ArgLength & 3)
+        write(OutFile, &Zeros, 4-(ArgLength&3));
+    }
+  }
+ 
+  /* Write out this record! */
+  PTy = PT;
+  write(OutFile, &PTy, sizeof(int));
+  write(OutFile, Start, NumElements*sizeof(unsigned));
+}
diff --git a/runtime/libprofile/FunctionProfiling.c b/runtime/libprofile/FunctionProfiling.c
new file mode 100644
index 00000000000..8bee2f9ba62
--- /dev/null
+++ b/runtime/libprofile/FunctionProfiling.c
@@ -0,0 +1,41 @@
+/*===-- FunctionProfiling.c - Support library for function profiling ------===*\
+|*
+|*                     The LLVM Compiler Infrastructure
+|*
+|* This file was developed by the LLVM research group and is distributed under
+|* the University of Illinois Open Source License. See LICENSE.TXT for details.
+|* 
+|*===----------------------------------------------------------------------===*|
+|* 
+|* This file implements the call back routines for the function profiling
+|* instrumentation pass.  This should be used with the
+|* -insert-function-profiling LLVM pass.
+|*
+\*===----------------------------------------------------------------------===*/
+
+#include "Profiling.h"
+#include <stdlib.h>
+
+static unsigned *ArrayStart;
+static unsigned NumElements;
+
+/* FuncProfAtExitHandler - When the program exits, just write out the profiling
+ * data.
+ */
+static void FuncProfAtExitHandler() {
+  /* Just write out the data we collected.
+   */
+  write_profiling_data(Function, ArrayStart, NumElements);
+}
+
+
+/* llvm_start_func_profiling - This is the main entry point of the function
+ * profiling library.  It is responsible for setting up the atexit handler.
+ */
+void llvm_start_func_profiling(int argc, const char **argv,
+                               unsigned *arrayStart, unsigned numElements) {
+  save_arguments(argc, argv);
+  ArrayStart = arrayStart;
+  NumElements = numElements;
+  atexit(FuncProfAtExitHandler);
+}
diff --git a/runtime/libprofile/Makefile b/runtime/libprofile/Makefile
new file mode 100644
index 00000000000..87badfec026
--- /dev/null
+++ b/runtime/libprofile/Makefile
@@ -0,0 +1,17 @@
+##===- runtime/libprofile/Makefile -------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file was developed by the LLVM research group and is distributed under
+# the University of Illinois Open Source License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL = ../..
+BYTECODE_LIBRARY=1
+SHARED_LIBRARY=1
+#DONT_BUILD_RELINKED=1
+LIBRARYNAME=profile_rt
+EXPORTED_SYMBOL_FILE = $(SourceDir)/exported_symbols.lst
+
+include $(LEVEL)/Makefile.common
+
diff --git a/runtime/libprofile/Profiling.h b/runtime/libprofile/Profiling.h
new file mode 100644
index 00000000000..bb7cc8bc96c
--- /dev/null
+++ b/runtime/libprofile/Profiling.h
@@ -0,0 +1,34 @@
+/*===-- Profiling.h - Profiling support library support routines --*- C -*-===*\
+|*
+|*                     The LLVM Compiler Infrastructure
+|*
+|* This file was developed by the LLVM research group and is distributed under
+|* the University of Illinois Open Source License. See LICENSE.TXT for details.
+|* 
+|*===----------------------------------------------------------------------===*|
+|* 
+|* This file defines functions shared by the various different profiling
+|* implementations.
+|*
+\*===----------------------------------------------------------------------===*/
+
+#ifndef PROFILING_H
+#define PROFILING_H
+
+/* save_arguments - Save argc and argv as passed into the program for the file
+ * we output.
+ */
+void save_arguments(int argc, const char **argv);
+
+enum ProfilingType {
+  Arguments = 1,   /* The command line argument block */
+  Function  = 2,   /* Function profiling information  */
+  Block     = 3,   /* Block profiling information     */
+  Edge      = 4,   /* Edge profiling information      */
+  Path      = 5    /* Path profiling information      */
+};
+
+void write_profiling_data(enum ProfilingType PT, unsigned *Start,
+                          unsigned NumElements);
+
+#endif
diff --git a/runtime/libprofile/exported_symbols.lst b/runtime/libprofile/exported_symbols.lst
new file mode 100644
index 00000000000..faed3efd203
--- /dev/null
+++ b/runtime/libprofile/exported_symbols.lst
@@ -0,0 +1,3 @@
+
+llvm_start_func_profiling
+llvm_start_block_profiling