kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC

arch/arc/Makefile overrides -O2 with -O3. This is the only user of
ARCH_CFLAGS. There is no user of ARCH_CPPFLAGS or ARCH_AFLAGS.
My plan is to remove ARCH_{CPP,A,C}FLAGS after refactoring the ARC
Makefile.

Currently, ARC has no way to enable -Wmaybe-uninitialized because both
-O3 and -Os disable it. Enabling it will be useful for compile-testing.
This commit allows allmodconfig (, which defaults to -O2) to enable it.

Add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y to all the defconfig files
in arch/arc/configs/ in order to keep the current config settings.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/Makefile b/Makefile
index 97f5d12547086f92682128ee428c4eda172c93af..c27bc98ad28bf1972e764b25a22581adf80fd12e 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -723,10 +723,12 @@ KBUILD_CFLAGS     += $(call cc-disable-warning, format-truncation)
 KBUILD_CFLAGS  += $(call cc-disable-warning, format-overflow)
 KBUILD_CFLAGS  += $(call cc-disable-warning, address-of-packed-member)
 
-ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS  += -Os
-else
-KBUILD_CFLAGS   += -O2
+ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
+KBUILD_CFLAGS += -O2
+else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
+KBUILD_CFLAGS += -O3
+else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
+KBUILD_CFLAGS += -Os
 endif
 
 ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED

diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index ee6d1184c2b1b557fef8bef69a1ae9cf2c90daa3..f1c44cccf8d6c4b6f85be7c13e319cfbcf9068d6 100644 (file)
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -48,14 +48,6 @@ endif
 cfi := $(call as-instr,.cfi_startproc\n.cfi_endproc,-DARC_DW2_UNWIND_AS_CFI)
 cflags-$(CONFIG_ARC_DW2_UNWIND)                += -fasynchronous-unwind-tables $(cfi)
 
-ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
-# Generic build system uses -O2, we want -O3
-# Note: No need to add to cflags-y as that happens anyways
-#
-# Disable the false maybe-uninitialized warings gcc spits out at -O3
-ARCH_CFLAGS += -O3 $(call cc-disable-warning,maybe-uninitialized,)
-endif
-
 # small data is default for elf32 tool-chain. If not usable, disable it
 # This also allows repurposing GP as scratch reg to gcc reg allocator
 disable_small_data := y

diff --git a/arch/arc/configs/axs101_defconfig b/arch/arc/configs/axs101_defconfig
index e31a8ebc3eccb0b628f71ea86d6632976154f360..0016149f958304a2420817650846eb4eafec81bd 100644 (file)
--- a/arch/arc/configs/axs101_defconfig
+++ b/arch/arc/configs/axs101_defconfig
@@ -9,6 +9,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

diff --git a/arch/arc/configs/axs103_defconfig b/arch/arc/configs/axs103_defconfig
index e0e8567f0d7585587ff4eee641f0fc814c8b1c77..5b031582a1cf8bad73f836f02d47380e6a557083 100644 (file)
--- a/arch/arc/configs/axs103_defconfig
+++ b/arch/arc/configs/axs103_defconfig
@@ -9,6 +9,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

diff --git a/arch/arc/configs/axs103_smp_defconfig b/arch/arc/configs/axs103_smp_defconfig
index fcbc952bc75bb973a941a829dad2db4443c0d824..d4eec39e0112c4e8511a046b64f05ea20dc417c3 100644 (file)
--- a/arch/arc/configs/axs103_smp_defconfig
+++ b/arch/arc/configs/axs103_smp_defconfig
@@ -9,6 +9,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

diff --git a/arch/arc/configs/haps_hs_defconfig b/arch/arc/configs/haps_hs_defconfig
index 436f2135bdc168fdf1edee8f88925719a30e3011..47ff8a97e42da648ca0ebdd990015444cf7864cd 100644 (file)
--- a/arch/arc/configs/haps_hs_defconfig
+++ b/arch/arc/configs/haps_hs_defconfig
@@ -10,6 +10,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_EXPERT=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_COMPAT_BRK is not set

diff --git a/arch/arc/configs/haps_hs_smp_defconfig b/arch/arc/configs/haps_hs_smp_defconfig
index 33a787c375e2e53437420e8df509117e2979e1e0..9685fd5f57a48229629295852688b7a723894a45 100644 (file)
--- a/arch/arc/configs/haps_hs_smp_defconfig
+++ b/arch/arc/configs/haps_hs_smp_defconfig
@@ -10,6 +10,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

diff --git a/arch/arc/configs/hsdk_defconfig b/arch/arc/configs/hsdk_defconfig
index 403125d9c9a344f28091273f33d52a2215d6772c..9b9a74444ce27455dd5f403e476de3b78d771a23 100644 (file)
--- a/arch/arc/configs/hsdk_defconfig
+++ b/arch/arc/configs/hsdk_defconfig
@@ -9,6 +9,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
 CONFIG_BLK_DEV_RAM=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

diff --git a/arch/arc/configs/nps_defconfig b/arch/arc/configs/nps_defconfig
index f0a077c00efa82099478c823502ce5aa2999e658..5978d4d7d5b0791c883c47d7834e664d8cd496cd 100644 (file)
--- a/arch/arc/configs/nps_defconfig
+++ b/arch/arc/configs/nps_defconfig
@@ -6,6 +6,7 @@ CONFIG_HIGH_RES_TIMERS=y
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_SYSCTL_SYSCALL=y
 # CONFIG_EPOLL is not set
 # CONFIG_SIGNALFD is not set

diff --git a/arch/arc/configs/nsim_700_defconfig b/arch/arc/configs/nsim_700_defconfig
index de398c7b10b317f568e98fac2ff599fdce5faacf..2b9b11474640c94cfb41fa4c950269d9a343f2ec 100644 (file)
--- a/arch/arc/configs/nsim_700_defconfig
+++ b/arch/arc/configs/nsim_700_defconfig
@@ -10,6 +10,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

diff --git a/arch/arc/configs/nsim_hs_defconfig b/arch/arc/configs/nsim_hs_defconfig
index 2dbd34a9ff0772b9a9cf2649f4a27558ac323def..bab3dd25584162915fa312e7e8f2bfb5f25270e7 100644 (file)
--- a/arch/arc/configs/nsim_hs_defconfig
+++ b/arch/arc/configs/nsim_hs_defconfig
@@ -10,6 +10,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

diff --git a/arch/arc/configs/nsim_hs_smp_defconfig b/arch/arc/configs/nsim_hs_smp_defconfig
index c7135f1e2583f02e9ca4e9cf60423cff901b98df..90d2d50fb8dc5d430d483a7bb5e2d368c48e7644 100644 (file)
--- a/arch/arc/configs/nsim_hs_smp_defconfig
+++ b/arch/arc/configs/nsim_hs_smp_defconfig
@@ -8,6 +8,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

diff --git a/arch/arc/configs/nsimosci_defconfig b/arch/arc/configs/nsimosci_defconfig
index 385a71d3c4785405b01c300b57758fac4159046d..5dd470b6609ebf2e061e1b48e98c86f5ef175056 100644 (file)
--- a/arch/arc/configs/nsimosci_defconfig
+++ b/arch/arc/configs/nsimosci_defconfig
@@ -10,6 +10,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

diff --git a/arch/arc/configs/nsimosci_hs_defconfig b/arch/arc/configs/nsimosci_hs_defconfig
index 248a2c3bdc12987ae8d39b5edef42245824f5259..3532e86f7bff690b4906d8c7f9ea8e9d6a5db117 100644 (file)
--- a/arch/arc/configs/nsimosci_hs_defconfig
+++ b/arch/arc/configs/nsimosci_hs_defconfig
@@ -10,6 +10,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

diff --git a/arch/arc/configs/nsimosci_hs_smp_defconfig b/arch/arc/configs/nsimosci_hs_smp_defconfig
index 1a4bc7b660fb5dbc2d8e3611fa5350f9de2d32d9..d90448bee064f3604631966dcd0e67253a44226f 100644 (file)
--- a/arch/arc/configs/nsimosci_hs_smp_defconfig
+++ b/arch/arc/configs/nsimosci_hs_smp_defconfig
@@ -8,6 +8,7 @@ CONFIG_IKCONFIG_PROC=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_COMPAT_BRK is not set
 CONFIG_KPROBES=y

diff --git a/arch/arc/configs/tb10x_defconfig b/arch/arc/configs/tb10x_defconfig
index dc739bd093e31956782f8b808e60f1f64102b0cb..3a138f8c729945f644ad9f9a63c800337bdb12d0 100644 (file)
--- a/arch/arc/configs/tb10x_defconfig
+++ b/arch/arc/configs/tb10x_defconfig
@@ -14,6 +14,7 @@ CONFIG_INITRAMFS_SOURCE="../tb10x-rootfs.cpio"
 CONFIG_INITRAMFS_ROOT_UID=2100
 CONFIG_INITRAMFS_ROOT_GID=501
 # CONFIG_RD_GZIP is not set
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_SYSCTL_SYSCALL=y
 CONFIG_KALLSYMS_ALL=y
 # CONFIG_AIO is not set

diff --git a/arch/arc/configs/vdk_hs38_defconfig b/arch/arc/configs/vdk_hs38_defconfig
index 0c3b214168197d1c709e4f428d4d02a4b93d4a5a..d7c858df520cc07a0e22c8e3f0777356274d7002 100644 (file)
--- a/arch/arc/configs/vdk_hs38_defconfig
+++ b/arch/arc/configs/vdk_hs38_defconfig
@@ -4,6 +4,7 @@ CONFIG_HIGH_RES_TIMERS=y
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

diff --git a/arch/arc/configs/vdk_hs38_smp_defconfig b/arch/arc/configs/vdk_hs38_smp_defconfig
index f9ad9d3ee702d961da37d09f8c697175ce764d33..015c1d43889e6937073f3014cae500f372667091 100644 (file)
--- a/arch/arc/configs/vdk_hs38_smp_defconfig
+++ b/arch/arc/configs/vdk_hs38_smp_defconfig
@@ -4,6 +4,7 @@ CONFIG_HIGH_RES_TIMERS=y
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_BLK_DEV_INITRD=y
+CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

diff --git a/init/Kconfig b/init/Kconfig
index 149efd82447ff1d9d6a5f14cb9a22b1eebebe49d..92118505dd33f4779becf187e0e335ef52d63565 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1209,14 +1209,22 @@ choice
        default CC_OPTIMIZE_FOR_PERFORMANCE
 
 config CC_OPTIMIZE_FOR_PERFORMANCE
-       bool "Optimize for performance"
+       bool "Optimize for performance (-O2)"
        help
          This is the default optimization level for the kernel, building
          with the "-O2" compiler flag for best performance and most
          helpful compile-time warnings.
 
+config CC_OPTIMIZE_FOR_PERFORMANCE_O3
+       bool "Optimize more for performance (-O3)"
+       depends on ARC
+       imply CC_DISABLE_WARN_MAYBE_UNINITIALIZED  # avoid false positives
+       help
+         Choosing this option will pass "-O3" to your compiler to optimize
+         the kernel yet more for performance.
+
 config CC_OPTIMIZE_FOR_SIZE
-       bool "Optimize for size"
+       bool "Optimize for size (-Os)"
        imply CC_DISABLE_WARN_MAYBE_UNINITIALIZED  # avoid false positives
        help
          Choosing this option will pass "-Os" to your compiler resulting