diff --git a/core/config.mk b/core/config.mk
index 0b2e6b3684..80f74871bf 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -494,39 +494,53 @@ ALLOW_MISSING_DEPENDENCIES := true
 endif
 .KATI_READONLY := ALLOW_MISSING_DEPENDENCIES
 
-#
-# Tools that are prebuilts for TARGET_BUILD_APPS
-#
 prebuilt_sdk_tools := prebuilts/sdk/tools
 prebuilt_sdk_tools_bin := $(prebuilt_sdk_tools)/$(HOST_OS)/bin
 
-AIDL := $(HOST_OUT_EXECUTABLES)/aidl
-AAPT := $(HOST_OUT_EXECUTABLES)/aapt
-AAPT2 := $(HOST_OUT_EXECUTABLES)/aapt2
-ZIPALIGN := $(HOST_OUT_EXECUTABLES)/zipalign
-SIGNAPK_JAR := $(HOST_OUT_JAVA_LIBRARIES)/signapk$(COMMON_JAVA_PACKAGE_SUFFIX)
-SIGNAPK_JNI_LIBRARY_PATH := $(HOST_OUT_SHARED_LIBRARIES)
-LLVM_RS_CC := $(HOST_OUT_EXECUTABLES)/llvm-rs-cc
-BCC_COMPAT := $(HOST_OUT_EXECUTABLES)/bcc_compat
-DEPMOD := $(HOST_OUT_EXECUTABLES)/depmod
+USE_PREBUILT_SDK_TOOLS_IN_PLACE := true
 
-#TODO: use a smaller -Xmx value for most libraries;
-#      only core.jar and framework.jar need a heap this big.
-ifndef DX_ALT_JAR
-DX := $(HOST_OUT_EXECUTABLES)/dx
-DX_COMMAND := $(DX) -JXms16M -JXmx2048M
+#
+# Tools that are prebuilts for TARGET_BUILD_APPS
+#
+ifeq (,$(TARGET_BUILD_APPS)$(filter true,$(TARGET_BUILD_PDK)))
+  AIDL := $(HOST_OUT_EXECUTABLES)/aidl
+  AAPT := $(HOST_OUT_EXECUTABLES)/aapt
+  AAPT2 := $(HOST_OUT_EXECUTABLES)/aapt2
+  MAINDEXCLASSES := $(HOST_OUT_EXECUTABLES)/mainDexClasses
+  SIGNAPK_JAR := $(HOST_OUT_JAVA_LIBRARIES)/signapk$(COMMON_JAVA_PACKAGE_SUFFIX)
+  SIGNAPK_JNI_LIBRARY_PATH := $(HOST_OUT_SHARED_LIBRARIES)
+  ZIPALIGN := $(HOST_OUT_EXECUTABLES)/zipalign
+
+  ifndef DX_ALT_JAR
+    DX := $(HOST_OUT_EXECUTABLES)/dx
+    DX_COMMAND := $(DX) -JXms16M -JXmx2048M
+  else
+    DX := $(DX_ALT_JAR)
+    DX_COMMAND := $(JAVA) -Xms16M -Xmx2048M -jar $(DX)
+  endif
+else # TARGET_BUILD_APPS || TARGET_BUILD_PDK
+  AIDL := $(prebuilt_sdk_tools_bin)/aidl
+  AAPT := $(prebuilt_sdk_tools_bin)/aapt
+  AAPT2 := $(prebuilt_sdk_tools_bin)/aapt2
+  DX := $(prebuilt_sdk_tools)/dx
+  DX_COMMAND := $(DX) -JXms16M -JXmx2048M
+  MAINDEXCLASSES := $(prebuilt_sdk_tools)/mainDexClasses
+  ZIPALIGN := $(prebuilt_sdk_tools_bin)/zipalign
+  SIGNAPK_JAR := $(prebuilt_sdk_tools)/lib/signapk$(COMMON_JAVA_PACKAGE_SUFFIX)
+  SIGNAPK_JNI_LIBRARY_PATH := $(prebuilt_sdk_tools)/$(HOST_OS)/lib64
+endif # TARGET_BUILD_APPS || TARGET_BUILD_PDK
+
+ifeq (,$(TARGET_BUILD_APPS))
+  # Use RenderScript prebuilts for unbundled builds but not PDK builds
+  LLVM_RS_CC := $(HOST_OUT_EXECUTABLES)/llvm-rs-cc
+  BCC_COMPAT := $(HOST_OUT_EXECUTABLES)/bcc_compat
 else
-DX := $(DX_ALT_JAR)
-DX_COMMAND := $(JAVA) -Xms16M -Xmx2048M -jar $(DX)
-endif
+  LLVM_RS_CC := $(prebuilt_sdk_tools_bin)/llvm-rs-cc
+  BCC_COMPAT := $(prebuilt_sdk_tools_bin)/bcc_compat
+endif # TARGET_BUILD_PDK
 
-MAINDEXCLASSES := $(HOST_OUT_EXECUTABLES)/mainDexClasses
-
-SOONG_ZIP := $(SOONG_HOST_OUT_EXECUTABLES)/soong_zip
-ZIP2ZIP := $(SOONG_HOST_OUT_EXECUTABLES)/zip2zip
-FILESLIST := $(SOONG_HOST_OUT_EXECUTABLES)/fileslist
-
-SOONG_JAVAC_WRAPPER := $(SOONG_HOST_OUT_EXECUTABLES)/soong_javac_wrapper
+prebuilt_sdk_tools :=
+prebuilt_sdk_tools_bin :=
 
 # Always use prebuilts for ckati and makeparallel
 prebuilt_build_tools := prebuilts/build-tools
@@ -535,38 +549,18 @@ prebuilt_build_tools_bin := $(prebuilt_build_tools)/$(HOST_PREBUILT_TAG)/bin
 else
 prebuilt_build_tools_bin := $(prebuilt_build_tools)/$(HOST_PREBUILT_TAG)/asan/bin
 endif
+
 ACP := $(prebuilt_build_tools_bin)/acp
 CKATI := $(prebuilt_build_tools_bin)/ckati
+DEPMOD := $(HOST_OUT_EXECUTABLES)/depmod
+FILESLIST := $(SOONG_HOST_OUT_EXECUTABLES)/fileslist
 IJAR := $(prebuilt_build_tools_bin)/ijar
 MAKEPARALLEL := $(prebuilt_build_tools_bin)/makeparallel
+SOONG_JAVAC_WRAPPER := $(SOONG_HOST_OUT_EXECUTABLES)/soong_javac_wrapper
+SOONG_ZIP := $(SOONG_HOST_OUT_EXECUTABLES)/soong_zip
+ZIP2ZIP := $(SOONG_HOST_OUT_EXECUTABLES)/zip2zip
 ZIPTIME := $(prebuilt_build_tools_bin)/ziptime
 
-USE_PREBUILT_SDK_TOOLS_IN_PLACE := true
-
-# Override the definitions above for unbundled and PDK builds
-ifneq (,$(TARGET_BUILD_APPS)$(filter true,$(TARGET_BUILD_PDK)))
-AIDL := $(prebuilt_sdk_tools_bin)/aidl
-AAPT := $(prebuilt_sdk_tools_bin)/aapt
-AAPT2 := $(prebuilt_sdk_tools_bin)/aapt2
-ZIPALIGN := $(prebuilt_sdk_tools_bin)/zipalign
-SIGNAPK_JAR := $(prebuilt_sdk_tools)/lib/signapk$(COMMON_JAVA_PACKAGE_SUFFIX)
-# Use 64-bit libraries unconditionally because 32-bit JVMs are no longer supported
-SIGNAPK_JNI_LIBRARY_PATH := $(prebuilt_sdk_tools)/$(HOST_OS)/lib64
-
-DX := $(prebuilt_sdk_tools)/dx
-DX_COMMAND := $(DX) -JXms16M -JXmx2048M
-MAINDEXCLASSES := $(prebuilt_sdk_tools)/mainDexClasses
-
-# Don't use prebuilts in PDK
-ifneq ($(TARGET_BUILD_PDK),true)
-LLVM_RS_CC := $(prebuilt_sdk_tools_bin)/llvm-rs-cc
-BCC_COMPAT := $(prebuilt_sdk_tools_bin)/bcc_compat
-endif # TARGET_BUILD_PDK
-endif # TARGET_BUILD_APPS || TARGET_BUILD_PDK
-prebuilt_sdk_tools :=
-prebuilt_sdk_tools_bin :=
-
-
 # ---------------------------------------------------------------
 # Generic tools.
 JACK := $(HOST_OUT_EXECUTABLES)/jack