diff --git a/libc/Android.mk b/libc/Android.mk
index 31807dd..d277551 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -515,7 +515,10 @@
 libc_common_cflags += -DTARGET_USES_LOGD
 endif
 
-use_clang := false
+use_clang := $(USE_CLANG_PLATFORM_BUILD)
+ifeq ($(use_clang),)
+  use_clang := false
+endif
 
 # Try to catch typical 32-bit assumptions that break with 64-bit pointers.
 libc_common_cflags += \
@@ -751,6 +754,13 @@
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := $(libc_upstream_openbsd_src_files)
+ifneq (,$(filter $(TARGET_ARCH),x86 x86_64))
+  # Clang has wrong long double size or LDBL_MANT_DIG, http://b/17163651.
+  LOCAL_CLANG := false
+else
+  LOCAL_CLANG := $(use_clang)
+endif
+
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
     -Wno-sign-compare -Wno-uninitialized -Wno-unused-parameter \
@@ -764,7 +774,6 @@
 LOCAL_CPPFLAGS := $(libc_common_cppflags)
 LOCAL_C_INCLUDES := $(libc_common_c_includes)
 LOCAL_MODULE := libc_openbsd
-LOCAL_CLANG := $(use_clang)
 LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
 LOCAL_SYSTEM_SHARED_LIBRARIES :=
 
@@ -783,6 +792,13 @@
 
 LOCAL_SRC_FILES_32 := $(libc_upstream_openbsd_gdtoa_src_files_32)
 LOCAL_SRC_FILES_64 := $(libc_upstream_openbsd_gdtoa_src_files_64)
+ifneq (,$(filter $(TARGET_ARCH),x86 x86_64))
+  # Clang has wrong long double size or LDBL_MANT_DIG, http://b/17163651.
+  LOCAL_CLANG := false
+else
+  LOCAL_CLANG := $(use_clang)
+endif
+
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
     -Wno-sign-compare -Wno-uninitialized \
@@ -796,7 +812,6 @@
 LOCAL_CPPFLAGS := $(libc_common_cppflags)
 LOCAL_C_INCLUDES := $(libc_common_c_includes)
 LOCAL_MODULE := libc_gdtoa
-LOCAL_CLANG := $(use_clang)
 LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
 LOCAL_SYSTEM_SHARED_LIBRARIES :=
 
@@ -814,6 +829,11 @@
 LOCAL_CFLAGS := $(libc_common_cflags) \
     -Wframe-larger-than=2048 \
 
+ifeq ($(TARGET_ARCH),x86_64)
+  # Clang assembler has problem with ssse3-strcmp-slm.S, http://b/17302991
+  LOCAL_CLANG_ASFLAGS += -no-integrated-as
+endif
+
 LOCAL_CONLYFLAGS := $(libc_common_conlyflags)
 LOCAL_CPPFLAGS := $(libc_common_cppflags)
 LOCAL_C_INCLUDES := $(libc_common_c_includes)