diff --git a/core/combo/darwin-x86.mk b/core/combo/darwin-x86.mk
index 2150960..47f5ccd 100644
--- a/core/combo/darwin-x86.mk
+++ b/core/combo/darwin-x86.mk
@@ -29,6 +29,7 @@
         -o $@ \
         $(PRIVATE_LDFLAGS) \
         $(if $(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES),-all_load) \
+        $(TARGET_FDO_LIB) \
         $(TARGET_LIBGCC)
 endef
 
@@ -42,6 +43,7 @@
         $(PRIVATE_LDLIBS) \
         $(call normalize-target-libraries,$(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
         $(call normalize-target-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
+        $(TARGET_FDO_LIB) \
         $(TARGET_LIBGCC)
 endef
 
@@ -55,6 +57,7 @@
         $(PRIVATE_LDLIBS) \
         $(call normalize-target-libraries,$(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
         $(call normalize-target-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
+        $(TARGET_FDO_LIB) \
         $(TARGET_LIBGCC)
 endef
 
@@ -94,4 +97,3 @@
 endef
 
 endif
-
diff --git a/core/combo/linux-arm.mk b/core/combo/linux-arm.mk
index c0a530f..44d3540 100644
--- a/core/combo/linux-arm.mk
+++ b/core/combo/linux-arm.mk
@@ -135,6 +135,37 @@
 $(combo_target)LIBGCC := $(shell $($(combo_target)CC) $($(combo_target)GLOBAL_CFLAGS) -print-libgcc-file-name)
 endif
 
+# Define FDO (Feedback Directed Optimization) options.
+
+TARGET_FDO_CFLAGS:=
+TARGET_FDO_LIB:=
+
+target_libgcov := $(shell $($(combo_target)CC) $($(combo_target)GLOBAL_CFLAGS) \
+        --print-file-name=libgcov.a)
+ifneq ($(strip $(BUILD_FDO_INSTRUMENT)),)
+  # Set BUILD_FDO_INSTRUMENT=true to turn on FDO instrumentation.
+  # The profile will be generated on /data/local/tmp/profile on the device.
+  TARGET_FDO_CFLAGS := -fprofile-generate=/data/local/tmp/profile -DANDROID_FDO
+  TARGET_FDO_LIB := $(target_libgcov)
+else
+  # If BUILD_FDO_INSTRUMENT is turned off, then consider doing the FDO optimizations.
+  # Set TARGET_FDO_PROFILE_PATH to set a custom profile directory for your build.
+  ifeq ($(strip $(TARGET_FDO_PROFILE_PATH)),)
+    TARGET_FDO_PROFILE_PATH := fdo/profiles/$(TARGET_ARCH)/$(TARGET_ARCH_VARIANT)
+  else
+    ifeq ($(strip $(wildcard $(TARGET_FDO_PROFILE_PATH))),)
+      $(warning Custom TARGET_FDO_PROFILE_PATH supplied, but directory does not exist. Turn off FDO.)
+    endif
+  endif
+
+  # If the FDO profile directory can't be found, then FDO is off.
+  ifneq ($(strip $(wildcard $(TARGET_FDO_PROFILE_PATH))),)
+    TARGET_FDO_CFLAGS := -fprofile-use=$(TARGET_FDO_PROFILE_PATH) -DANDROID_FDO
+    TARGET_FDO_LIB := $(target_libgcov)
+  endif
+endif
+
+
 # unless CUSTOM_KERNEL_HEADERS is defined, we're going to use
 # symlinks located in out/ to point to the appropriate kernel
 # headers. see 'config/kernel_headers.make' for more details
@@ -185,6 +216,7 @@
 	-o $@ \
 	$(PRIVATE_LDFLAGS) \
 	$(TARGET_GLOBAL_LDFLAGS) \
+	$(TARGET_FDO_LIB) \
 	$(TARGET_LIBGCC)
 endef
 
@@ -202,6 +234,7 @@
 	$(call normalize-target-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
 	$(PRIVATE_LDFLAGS) \
 	$(TARGET_GLOBAL_LDFLAGS) \
+	$(TARGET_FDO_LIB) \
 	$(TARGET_LIBGCC) \
 	$(TARGET_CRTEND_O)
 endef
@@ -216,6 +249,7 @@
 	$(TARGET_GLOBAL_LDFLAGS) \
 	$(PRIVATE_ALL_OBJECTS) \
 	$(call normalize-target-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
+	$(TARGET_FDO_LIB) \
 	$(TARGET_LIBGCC) \
 	$(TARGET_CRTEND_O)
 endef