Revert: '[Squashed] Hell lot of optimization with a hell lot of commits'

LPAE indicates better instructions can be used when atomicity guarantees are
needed. However, LPAE's presence isn't advertised by clang/GCC. We fake an
ARM feature to advertise its presence on architectures where it is.
Also, add a TODO documenting that cortex-a15 is not the correct CPU variant
for krait.

Change-Id: I02a1248025c32d94eca0bc8a249dc524f1ac9c36
Signed-off-by: Chet Kener <[email protected]>

Conflicts:
	core/combo/arch/arm/armv7-a-neon.mk

OptiPop Optimizations V2

* A squash of al lof the optimizations added since November 2014.  This the build setup I find works best for my Nexus 5 after hundreds of hours of testing.

Options you can enable in bashrc using exports or BoardConfig.mk by just adding as follows:

GRAPHITE_OPTS=true - Enables Graphite Optimizations

STRICT_ALIASING=true - Enabled Strict Aliasing Optimizations

USE_O3_OPTIMIZATIONS=true - Enables Clang and GCC -O3 Optimizations

USE_HOST_4_8=true - Switches from default Host GCC 4.6 Toolchain to the latest Google GCC 4.8 Host Toolchain

KRAIT_TUNINGS=true - Enables cortex-a15 tunings that work well with krait CPUs

ENABLE_GCCONLY=true - Enables many extra GCC Flags for things built with GCC (and also avoids clang because these flags are not supported by clang)

TARGET_USE_PIPE=true - Enable pipe flags which by my testing speed up the build by 5 minutes on regular hard drives (not really needed on SSD)

FLOOP_NEST_OPTIMIZE=true - Very Aggressive Optimization which I enabled for ART/Bionic learn more here: http://en.wikipedia.org/wiki/Loop_nest_optimization

Signed-off-by: Chet Kener <[email protected]>

Add Toolchain Version to Lunch Menu

Signed-off-by: Chet Kener <[email protected]>

armv7-a: More Specific Tunings per CPU

* Also add some substitutions and ignores for clang.

Signed-off-by: Chet Kener <[email protected]>

Conflicts:
	core/combo/arch/arm/armv7-a-neon.mk

Disable Strict on Linker

Signed-off-by: Chet Kener <[email protected]>

Fix Graphite Compile

Signed-off-by: Chet Kener <[email protected]>

Restore Missing -fgraphite-identity

* Somehow this went missing when copying grpahite flags from Kernel to ROM.  Thanks to @ImTheReas0n for noticing so we can have the best optimization possible.

Signed-off-by: Chet Kener <[email protected]>

Fix Graphite Compile on GCC 4.9

Signed-off-by: Chet Kener <[email protected]>

Update Floop Nest Optimize Module List

Signed-off-by: Chet Kener <[email protected]>

GCC 4.9

Fix Compile

Signed-off-by: Chet Kener <[email protected]>

Strict: Fix N6 Camera build

Signed-off-by: Chet Kener <[email protected]>

Fix The N6 Camera for Real!

Signed-off-by: Chet Kener <[email protected]>

optipop.mk:ffast-math:initial introduction

clang: Introduce and guard LDFlags

We have not been fully taking advantage of clang.  Let's include some linker flags that work on clang similar to what we are doing with GCC stuff.

Signed-off-by: Chet Kener <[email protected]>

host: Allow more arch flexibility

Prescott tuning may not always be the best option. Also be aware that allowing  -march=native will not work correctly with anything that is not Linux.  Mac and Windows users beware!!!

Sources: https://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html

Signed-off-by: Chet Kener <[email protected]>

arm: Update filter to 5.0

* Let's make sure we never have to worry about this

Signed-off-by: Chet Kener <[email protected]>

Remove "-g" globally

* -g is pretty worthless if you ask me.  Read here for more info https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html

Signed-off-by: Chet Kener <[email protected]>

Add krait as a CPU_VARIANT for arm flags....wtf CM

Change-Id: Ic057eff15310c91dc7dc3aff32379b99266180a5

optipop.mk :add some restrictions for graphite

Change-Id: I6c5de3c10eafbc228b7f9ea5735cf749cea747d0

optipop.mk :add some restrictions for strict

Change-Id: Ica80d34278b988c51706779a3cef992781f3ab09

Add PThread

Change-Id: I054a3e257b38fec411224953a606745a71276649

optipop:mk: remove libc_bionic and libc_dns from force disable strict

Change-Id: Id8b157d1de021e0ebc5d246a4b7cf53676eb2d5c

dumpvar:print all build optimizations

Change-Id: Icc7a6d949d412afa96aac0cf5c8c6c182aefebff

force arm-eabi-4.8 for kernel

Disable strict aliasing for malloc

Signed-off-by: CallMeAldy <[email protected]>

Author: travp624

core/binary.mk

@@ -97,8 +97,6 @@ else
   endif
 endif
 
-include $(BUILD_SYSTEM)/optipop.mk
-
 # The following LOCAL_ variables will be modified in this file.
 # Because the same LOCAL_ variables may be used to define modules for both 1st arch and 2nd arch,
 # we can't modify them in place.

core/clang/HOST_x86_common.mk

@@ -15,25 +15,14 @@ CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CFLAGS := \
   -no-integrated-as
 
 ifneq ($(strip $($(clang_2nd_arch_prefix)HOST_IS_64_BIT)),)
-ifeq ($(USE_HOST_4_8),true)
 CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS := \
   --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
   --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
   -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.8 \
   -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.8/x86_64-linux \
   -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.8/backward \
   -no-integrated-as
-else
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS := \
-  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6 \
-  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/x86_64-linux \
-  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/backward \
-  -no-integrated-as
-endif
 
-ifeq ($(USE_HOST_4_8),true)
 CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
   --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
   --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
@@ -43,35 +32,14 @@ CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
   -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/lib64/ \
   -no-integrated-as
 else
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
-  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -B$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/bin \
-  -B$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6 \
-  -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6 \
-  -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/lib64/ \
-  -no-integrated-as
-endif
-else
-ifeq ($(USE_HOST_4_8),true)
 CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS := \
   --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
   --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
   -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.8 \
   -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.8/x86_64-linux/32 \
   -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.8/backward \
   -no-integrated-as
-else
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS := \
-  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6 \
-  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/x86_64-linux/32 \
-  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/backward \
-  -no-integrated-as
-endif
 
-ifeq ($(USE_HOST_4_8),true)
 CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
   --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
   --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
@@ -80,16 +48,6 @@ CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
   -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.8/32 \
   -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/lib32/ \
   -no-integrated-as
-else
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
-  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -B$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/bin \
-  -B$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6/32 \
-  -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6/32 \
-  -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/lib32/ \
-  -no-integrated-as
-endif
 endif
 endif  # Linux
 

core/clang/arm.mk

@@ -22,19 +22,11 @@ CLANG_CONFIG_arm_UNKNOWN_CFLAGS := \
   -fno-builtin-sin \
   -fno-strict-volatile-bitfields \
   -fno-align-jumps \
-  -Wa,--noexecstack \
-  -Wno-unused-local-typedefs \
-  -fpredictive-commoning \
-  -ftree-loop-distribute-patterns \
-  -fvect-cost-model \
-  -ftree-partial-pre \
-  -fipa-cp-clone \
-  -mvectorize-with-neon-quad
+  -Wa,--noexecstack
 
 define subst-clang-incompatible-arm-flags
   $(subst -march=armv5te,-march=armv5t,\
   $(subst -march=armv5e,-march=armv5,\
-  $(subst -mfpu=neon-vfpv3,-mfpu=neon,\
-  $(subst -mfpu=neon-vfpv4,-mfpu=neon,\
-  $(1)))))
+  $(subst -mcpu=cortex-a15,-march=armv7-a,\
+  $(1))))
 endef

core/clang/arm64.mk

@@ -20,6 +20,5 @@ CLANG_CONFIG_arm64_UNKNOWN_CFLAGS := \
 
 # We don't have any arm64 flags to substitute yet.
 define subst-clang-incompatible-arm64-flags
-  $(subst -mfpu=neon-vfpv4,-mfpu=neon,\
-  $(1))
+  $(1)
 endef

core/clang/config.mk

@@ -31,15 +31,9 @@ endif
 
 # Clang flags for all host or target rules
 CLANG_CONFIG_EXTRA_ASFLAGS :=
-ifeq ($(USE_O3_OPTIMIZATIONS),true)
-CLANG_CONFIG_EXTRA_CFLAGS := -O3 -Qunused-arguments -Wno-unknown-warning-option
-CLANG_CONFIG_EXTRA_CPPFLAGS := -O3 -Qunused-arguments -Wno-unknown-warning-option -D__compiler_offsetof=__builtin_offsetof
-CLANG_CONFIG_EXTRA_LDFLAGS := -Wl,--sort-common
-else
 CLANG_CONFIG_EXTRA_CFLAGS :=
 CLANG_CONFIG_EXTRA_CPPFLAGS :=
 CLANG_CONFIG_EXTRA_LDFLAGS :=
-endif
 
 CLANG_CONFIG_EXTRA_CFLAGS += \
   -D__compiler_offsetof=__builtin_offsetof

core/combo/HOST_linux-x86.mk

@@ -18,11 +18,7 @@
 # Included by combo/select.mk
 
 ifeq ($(strip $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)),)
-ifeq ($(USE_HOST_4_8),true)
-$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.15-4.8/bin/x86_64-linux-
-else
-$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/bin/x86_64-linux-
-endif
+$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.8/bin/x86_64-linux-
 endif
 # Don't do anything if the toolchain is not there
 ifneq (,$(strip $(wildcard $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)gcc)))
@@ -32,14 +28,10 @@ $(combo_2nd_arch_prefix)HOST_AR  := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PRE
 endif # $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)gcc exists
 
 # gcc location for clang; to be updated when clang is updated
-ifeq ($(USE_HOST_4_8),true)
-$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.15-4.8/
-else
-$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/
-endif
+$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.8/
 
 # We expect SSE3 floating point math.
-$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -mstackrealign -msse3 -mfpmath=sse -m32 -Wa,--noexecstack -march=native
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -mstackrealign -msse3 -mfpmath=sse -m32 -Wa,--noexecstack -march=prescott
 $(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += -m32 -Wl,-z,noexecstack
 
 ifneq ($(strip $(BUILD_HOST_static)),)

core/combo/HOST_linux-x86_64.mk

@@ -18,11 +18,7 @@
 # Included by combo/select.mk
 
 ifeq ($(strip $(HOST_TOOLCHAIN_PREFIX)),)
-ifeq ($(USE_HOST_4_8),true)
-HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.15-4.8/bin/x86_64-linux-
-else
-HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/bin/x86_64-linux-
-endif
+HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.8/bin/x86_64-linux-
 endif
 # Don't do anything if the toolchain is not there
 ifneq (,$(strip $(wildcard $(HOST_TOOLCHAIN_PREFIX)gcc)))
@@ -32,13 +28,9 @@ HOST_AR  := $(HOST_TOOLCHAIN_PREFIX)ar
 endif # $(HOST_TOOLCHAIN_PREFIX)gcc exists
 
 # gcc location for clang; to be updated when clang is updated
-ifeq ($(USE_HOST_4_8),true)
-HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.15-4.8/
-else
-HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/
-endif
+HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.8/
 
-HOST_GLOBAL_CFLAGS += -m64 -Wa,--noexecstack -march=native
+HOST_GLOBAL_CFLAGS += -m64 -Wa,--noexecstack
 HOST_GLOBAL_LDFLAGS += -m64 -Wl,-z,noexecstack
 
 ifneq ($(strip $(BUILD_HOST_static)),)

core/combo/TARGET_linux-arm.mk

@@ -35,10 +35,10 @@ TARGET_$(combo_2nd_arch_prefix)ARCH_VARIANT := armv5te
 endif
 
 # Decouple NDK library selection with platform compiler version
-$(combo_2nd_arch_prefix)TARGET_NDK_GCC_VERSION := 4.9
+$(combo_2nd_arch_prefix)TARGET_NDK_GCC_VERSION := 4.8
 
 ifeq ($(strip $(TARGET_GCC_VERSION_EXP)),)
-$(combo_2nd_arch_prefix)TARGET_GCC_VERSION := 4.9
+$(combo_2nd_arch_prefix)TARGET_GCC_VERSION := 4.8
 else
 $(combo_2nd_arch_prefix)TARGET_GCC_VERSION := $(TARGET_GCC_VERSION_EXP)
 endif
@@ -67,13 +67,16 @@ $(combo_2nd_arch_prefix)TARGET_STRIP := $($(combo_2nd_arch_prefix)TARGET_TOOLS_P
 
 $(combo_2nd_arch_prefix)TARGET_NO_UNDEFINED_LDFLAGS := -Wl,--no-undefined
 
-ifeq ($(USE_O3_OPTIMIZATIONS),true)
-$(combo_2nd_arch_prefix)TARGET_arm_CFLAGS := -O3 -DNDEBUG -pipe -fomit-frame-pointer -funswitch-loops -fno-tree-vectorize -fno-inline-functions -fivopts -ffunction-sections -fdata-sections -frename-registers -fomit-frame-pointer -ftracer -Wno-unused-parameter -Wno-unused-but-set-variable -Wno-maybe-uninitialized
-$(combo_2nd_arch_prefix)TARGET_thumb_CFLAGS :=  -mthumb -Os -DNDEBUG -pipe -fomit-frame-pointer -fstrict-aliasing -fno-tree-vectorize -fno-inline-functions -fno-unswitch-loops -fivopts -ffunction-sections -fdata-sections -ftracer -Wno-unused-parameter -Wno-unused-but-set-variable -Wno-maybe-uninitialized -Wno-clobbered -Wno-strict-overflow
-else
-$(combo_2nd_arch_prefix)TARGET_arm_CFLAGS := -O2 -fomit-frame-pointer -fstrict-aliasing -funswitch-loops
-$(combo_2nd_arch_prefix)TARGET_thumb_CFLAGS := -mthumb -Os -fomit-frame-pointer -fno-strict-aliasing
-endif
+$(combo_2nd_arch_prefix)TARGET_arm_CFLAGS :=    -O2 \
+                        -fomit-frame-pointer \
+                        -fstrict-aliasing    \
+                        -funswitch-loops
+
+# Modules can choose to compile some source as thumb.
+$(combo_2nd_arch_prefix)TARGET_thumb_CFLAGS :=  -mthumb \
+                        -Os \
+                        -fomit-frame-pointer \
+                        -fno-strict-aliasing
 
 # Set FORCE_ARM_DEBUGGING to "true" in your buildspec.mk
 # or in your environment to force a full arm build, even for
@@ -85,14 +88,13 @@ endif
 # with -mlong-calls.  When built at -O0, those libraries are
 # too big for a thumb "BL <label>" to go from one end to the other.
 ifeq ($(FORCE_ARM_DEBUGGING),true)
-  $(combo_2nd_arch_prefix)TARGET_arm_CFLAGS += -fno-omit-frame-pointer
+  $(combo_2nd_arch_prefix)TARGET_arm_CFLAGS += -fno-omit-frame-pointer -fno-strict-aliasing
   $(combo_2nd_arch_prefix)TARGET_thumb_CFLAGS += -marm -fno-omit-frame-pointer
 endif
 
 android_config_h := $(call select-android-config-h,linux-arm)
 
 $(combo_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS += \
-                        -pipe \
 			-msoft-float \
 			-ffunction-sections \
 			-fdata-sections \
@@ -112,7 +114,7 @@ $(combo_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS += \
 # "-Wall -Werror" due to a commom idiom "ALOGV(mesg)" where ALOGV is turned
 # into no-op in some builds while mesg is defined earlier. So we explicitly
 # disable "-Wunused-but-set-variable" here.
-ifneq ($(filter 4.6 4.6.% 4.7 4.7.% 4.8 4.8.% 4.9 4.9.% 5.0 5.0.%, $($(combo_2nd_arch_prefix)TARGET_GCC_VERSION)),)
+ifneq ($(filter 4.6 4.6.% 4.7 4.7.% 4.8, $($(combo_2nd_arch_prefix)TARGET_GCC_VERSION)),)
 $(combo_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS += -fno-builtin-sin \
 			-fno-strict-volatile-bitfields
 endif
@@ -138,13 +140,16 @@ $(combo_2nd_arch_prefix)TARGET_GLOBAL_LDFLAGS += \
 
 $(combo_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS += -mthumb-interwork
 
-ifeq ($(USE_O3_OPTIMIZATIONS),true)
-$(combo_2nd_arch_prefix)TARGET_GLOBAL_CPPFLAGS += -fvisibility-inlines-hidden -O3 -DNDEBUG -pipe -fivopts -ffunction-sections -fdata-sections -funswitch-loops -fomit-frame-pointer -ftracer -Wno-unused-parameter -Wno-unused-but-set-variable -Wno-maybe-uninitialized
-$(combo_2nd_arch_prefix)TARGET_RELEASE_CFLAGS := -O3 -DNDEBUG -pipe -frerun-cse-after-loop -frename-registers -fstrict-aliasing -fivopts -ffunction-sections -fdata-sections -funswitch-loops -fomit-frame-pointer -ftracer -Wno-unused-parameter -Wno-unused-but-set-variable -Wno-maybe-uninitialized
-else
 $(combo_2nd_arch_prefix)TARGET_GLOBAL_CPPFLAGS += -fvisibility-inlines-hidden
-$(combo_2nd_arch_prefix)TARGET_RELEASE_CFLAGS := -DNDEBUG -Wstrict-aliasing=2 -fgcse-after-reload -frerun-cse-after-loop -frename-registers
-endif
+
+# More flags/options can be added here
+$(combo_2nd_arch_prefix)TARGET_RELEASE_CFLAGS := \
+			-DNDEBUG \
+			-g \
+			-Wstrict-aliasing=2 \
+			-fgcse-after-reload \
+			-frerun-cse-after-loop \
+			-frename-registers
 
 libc_root := bionic/libc
 libm_root := bionic/libm

core/combo/TARGET_linux-arm64.mk

@@ -118,7 +118,7 @@ TARGET_GLOBAL_CPPFLAGS += -fvisibility-inlines-hidden
 # More flags/options can be added here
 TARGET_RELEASE_CFLAGS := \
 			-DNDEBUG \
-			-O2 \
+			-O2 -g \
 			-Wstrict-aliasing=2 \
 			-fgcse-after-reload \
 			-frerun-cse-after-loop \

core/combo/TARGET_linux-mips.mk

@@ -113,6 +113,7 @@ $(combo_2nd_arch_prefix)TARGET_GLOBAL_CPPFLAGS += -fvisibility-inlines-hidden
 # More flags/options can be added here
 $(combo_2nd_arch_prefix)TARGET_RELEASE_CFLAGS := \
 			-DNDEBUG \
+			-g \
 			-Wstrict-aliasing=2 \
 			-fgcse-after-reload \
 			-frerun-cse-after-loop \

core/combo/TARGET_linux-mips64.mk

@@ -113,6 +113,7 @@ TARGET_GLOBAL_CPPFLAGS += -fvisibility-inlines-hidden
 # More flags/options can be added here
 TARGET_RELEASE_CFLAGS := \
 			-DNDEBUG \
+			-g \
 			-Wstrict-aliasing=2 \
 			-fgcse-after-reload \
 			-frerun-cse-after-loop \

core/combo/arch/arm/armv7-a-neon.mk

@@ -7,29 +7,22 @@ ARCH_ARM_HAVE_VFP_D32           := true
 ARCH_ARM_HAVE_NEON              := true
 
 ifneq (,$(filter cortex-a15 krait denver,$(TARGET_$(combo_2nd_arch_prefix)CPU_VARIANT)))
-        # TODO: krait is not a cortex-a15, we set the variant to cortex-a15 so that
-	#       hardware divide operations are generated. This should be removed and a
-	#       krait CPU variant added to GCC/clang.
-	arch_variant_cflags := -mcpu=cortex-a15 -mfpu=neon-vfpv4 -mvectorize-with-neon-quad
-
-        # Fake ARM compiler flags as these processors support LPAE and VFP4 which GCC/clang
-	# doesn't advertise.
-	arch_variant_cflags += -D__ARM_FEATURE_LPAE=1 -D__ARM_FEATURE_VFP4=1
-else
-ifeq ($(strip $(TARGET_$(combo_2nd_arch_prefix)CPU_VARIANT)),cortex-a9)
-	arch_variant_cflags := -mcpu=cortex-a9 -mfpu=neon
+	arch_variant_cflags := -mcpu=cortex-a15
 else
-ifneq (,$(filter cortex-a8 scorpion,$(TARGET_$(combo_2nd_arch_prefix)CPU_VARIANT)))
-	arch_variant_cflags := -mcpu=cortex-a8 -mfpu=neon
-	arch_variant_ldflags := -Wl,--fix-cortex-a8
+ifeq ($(strip $(TARGET_$(combo_2nd_arch_prefix)CPU_VARIANT)),cortex-a8)
+	arch_variant_cflags := -mcpu=cortex-a8
 else
 ifeq ($(strip $(TARGET_$(combo_2nd_arch_prefix)CPU_VARIANT)),cortex-a7)
-	arch_variant_cflags := -mcpu=cortex-a7 -mfpu=neon
+	arch_variant_cflags := -mcpu=cortex-a7
 else
-	arch_variant_cflags := -march=armv7-a -mfpu=neon
-endif
+	arch_variant_cflags := -march=armv7-a
 endif
 endif
 endif
+
 arch_variant_cflags += \
-    -mfloat-abi=softfp
+    -mfloat-abi=softfp \
+    -mfpu=neon
+
+arch_variant_ldflags := \
+	-Wl,--fix-cortex-a8

core/combo/select.mk

@@ -48,17 +48,11 @@ $(combo_var_prefix)HAVE_STRERROR_R_STRRET := 1
 $(combo_var_prefix)HAVE_STRLCPY := 0
 $(combo_var_prefix)HAVE_STRLCAT := 0
 $(combo_var_prefix)HAVE_KERNEL_MODULES := 0
-ifeq ($(USE_O3_OPTIMIZATIONS),true)
-$(combo_var_prefix)GLOBAL_CFLAGS := -O3 -DNDEBUG -pipe -fivopts -ffunction-sections -fdata-sections -funswitch-loops -fomit-frame-pointer -ftracer -Wno-unused-parameter -Wno-unused-but-set-variable -Wno-maybe-uninitialized -fno-exceptions -Wno-multichar
-$(combo_var_prefix)RELEASE_CFLAGS := -O3 -DNDEBUG -pipe -fivopts -ffunction-sections -fdata-sections -funswitch-loops -fomit-frame-pointer -ftracer -Wno-unused-parameter -Wno-unused-but-set-variable -Wno-maybe-uninitialized
-$(combo_var_prefix)GLOBAL_CPPFLAGS := -O3 -DNDEBUG -pipe -fivopts -ffunction-sections -fdata-sections -funswitch-loops -fomit-frame-pointer -ftracer -Wno-unused-parameter -Wno-unused-but-set-variable -Wno-maybe-uninitialized
-$(combo_var_prefix)GLOBAL_LDFLAGS := -Wl,-O1 -Wl,--as-needed -Wl,--relax -Wl,--sort-common -Wl,--gc-sections
-else
+
 $(combo_var_prefix)GLOBAL_CFLAGS := -fno-exceptions -Wno-multichar
-$(combo_var_prefix)RELEASE_CFLAGS := -O2 -fno-strict-aliasing
+$(combo_var_prefix)RELEASE_CFLAGS := -O2 -g -fno-strict-aliasing
 $(combo_var_prefix)GLOBAL_CPPFLAGS :=
 $(combo_var_prefix)GLOBAL_LDFLAGS :=
-endif
 $(combo_var_prefix)GLOBAL_ARFLAGS := crsPD
 $(combo_var_prefix)GLOBAL_LD_DIRS :=