linux/lib/raid6/Makefile
Nathan Chancellor de9c0d49d8 ARM: 8833/1: Ensure that NEON code always compiles with Clang
While building arm32 allyesconfig, I ran into the following errors:

  arch/arm/lib/xor-neon.c:17:2: error: You should compile this file with
  '-mfloat-abi=softfp -mfpu=neon'

  In file included from lib/raid6/neon1.c:27:
  /home/nathan/cbl/prebuilt/lib/clang/8.0.0/include/arm_neon.h:28:2:
  error: "NEON support not enabled"

Building V=1 showed NEON_FLAGS getting passed along to Clang but
__ARM_NEON__ was not getting defined. Ultimately, it boils down to Clang
only defining __ARM_NEON__ when targeting armv7, rather than armv6k,
which is the '-march' value for allyesconfig.

>From lib/Basic/Targets/ARM.cpp in the Clang source:

  // This only gets set when Neon instructions are actually available, unlike
  // the VFP define, hence the soft float and arch check. This is subtly
  // different from gcc, we follow the intent which was that it should be set
  // when Neon instructions are actually available.
  if ((FPU & NeonFPU) && !SoftFloat && ArchVersion >= 7) {
    Builder.defineMacro("__ARM_NEON", "1");
    Builder.defineMacro("__ARM_NEON__");
    // current AArch32 NEON implementations do not support double-precision
    // floating-point even when it is present in VFP.
    Builder.defineMacro("__ARM_NEON_FP",
                        "0x" + Twine::utohexstr(HW_FP & ~HW_FP_DP));
  }

Ard Biesheuvel recommended explicitly adding '-march=armv7-a' at the
beginning of the NEON_FLAGS definitions so that __ARM_NEON__ always gets
definined by Clang. This doesn't functionally change anything because
that code will only run where NEON is supported, which is implicitly
armv7.

Link: https://github.com/ClangBuiltLinux/linux/issues/287

Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-02-12 15:20:09 +00:00

167 lines
5.1 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_RAID6_PQ) += raid6_pq.o
raid6_pq-y += algos.o recov.o tables.o int1.o int2.o int4.o \
int8.o int16.o int32.o
raid6_pq-$(CONFIG_X86) += recov_ssse3.o recov_avx2.o mmx.o sse1.o sse2.o avx2.o avx512.o recov_avx512.o
raid6_pq-$(CONFIG_ALTIVEC) += altivec1.o altivec2.o altivec4.o altivec8.o \
vpermxor1.o vpermxor2.o vpermxor4.o vpermxor8.o
raid6_pq-$(CONFIG_KERNEL_MODE_NEON) += neon.o neon1.o neon2.o neon4.o neon8.o recov_neon.o recov_neon_inner.o
raid6_pq-$(CONFIG_S390) += s390vx8.o recov_s390xc.o
hostprogs-y += mktables
quiet_cmd_unroll = UNROLL $@
cmd_unroll = $(AWK) -f$(srctree)/$(src)/unroll.awk -vN=$(UNROLL) < $< > $@
ifeq ($(CONFIG_ALTIVEC),y)
altivec_flags := -maltivec $(call cc-option,-mabi=altivec)
ifdef CONFIG_CC_IS_CLANG
# clang ppc port does not yet support -maltivec when -msoft-float is
# enabled. A future release of clang will resolve this
# https://bugs.llvm.org/show_bug.cgi?id=31177
CFLAGS_REMOVE_altivec1.o += -msoft-float
CFLAGS_REMOVE_altivec2.o += -msoft-float
CFLAGS_REMOVE_altivec4.o += -msoft-float
CFLAGS_REMOVE_altivec8.o += -msoft-float
CFLAGS_REMOVE_altivec8.o += -msoft-float
CFLAGS_REMOVE_vpermxor1.o += -msoft-float
CFLAGS_REMOVE_vpermxor2.o += -msoft-float
CFLAGS_REMOVE_vpermxor4.o += -msoft-float
CFLAGS_REMOVE_vpermxor8.o += -msoft-float
endif
endif
# The GCC option -ffreestanding is required in order to compile code containing
# ARM/NEON intrinsics in a non C99-compliant environment (such as the kernel)
ifeq ($(CONFIG_KERNEL_MODE_NEON),y)
NEON_FLAGS := -ffreestanding
ifeq ($(ARCH),arm)
NEON_FLAGS += -march=armv7-a -mfloat-abi=softfp -mfpu=neon
endif
CFLAGS_recov_neon_inner.o += $(NEON_FLAGS)
ifeq ($(ARCH),arm64)
CFLAGS_REMOVE_recov_neon_inner.o += -mgeneral-regs-only
CFLAGS_REMOVE_neon1.o += -mgeneral-regs-only
CFLAGS_REMOVE_neon2.o += -mgeneral-regs-only
CFLAGS_REMOVE_neon4.o += -mgeneral-regs-only
CFLAGS_REMOVE_neon8.o += -mgeneral-regs-only
endif
endif
targets += int1.c
$(obj)/int1.c: UNROLL := 1
$(obj)/int1.c: $(src)/int.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
targets += int2.c
$(obj)/int2.c: UNROLL := 2
$(obj)/int2.c: $(src)/int.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
targets += int4.c
$(obj)/int4.c: UNROLL := 4
$(obj)/int4.c: $(src)/int.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
targets += int8.c
$(obj)/int8.c: UNROLL := 8
$(obj)/int8.c: $(src)/int.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
targets += int16.c
$(obj)/int16.c: UNROLL := 16
$(obj)/int16.c: $(src)/int.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
targets += int32.c
$(obj)/int32.c: UNROLL := 32
$(obj)/int32.c: $(src)/int.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_altivec1.o += $(altivec_flags)
targets += altivec1.c
$(obj)/altivec1.c: UNROLL := 1
$(obj)/altivec1.c: $(src)/altivec.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_altivec2.o += $(altivec_flags)
targets += altivec2.c
$(obj)/altivec2.c: UNROLL := 2
$(obj)/altivec2.c: $(src)/altivec.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_altivec4.o += $(altivec_flags)
targets += altivec4.c
$(obj)/altivec4.c: UNROLL := 4
$(obj)/altivec4.c: $(src)/altivec.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_altivec8.o += $(altivec_flags)
targets += altivec8.c
$(obj)/altivec8.c: UNROLL := 8
$(obj)/altivec8.c: $(src)/altivec.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_vpermxor1.o += $(altivec_flags)
targets += vpermxor1.c
$(obj)/vpermxor1.c: UNROLL := 1
$(obj)/vpermxor1.c: $(src)/vpermxor.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_vpermxor2.o += $(altivec_flags)
targets += vpermxor2.c
$(obj)/vpermxor2.c: UNROLL := 2
$(obj)/vpermxor2.c: $(src)/vpermxor.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_vpermxor4.o += $(altivec_flags)
targets += vpermxor4.c
$(obj)/vpermxor4.c: UNROLL := 4
$(obj)/vpermxor4.c: $(src)/vpermxor.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_vpermxor8.o += $(altivec_flags)
targets += vpermxor8.c
$(obj)/vpermxor8.c: UNROLL := 8
$(obj)/vpermxor8.c: $(src)/vpermxor.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_neon1.o += $(NEON_FLAGS)
targets += neon1.c
$(obj)/neon1.c: UNROLL := 1
$(obj)/neon1.c: $(src)/neon.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_neon2.o += $(NEON_FLAGS)
targets += neon2.c
$(obj)/neon2.c: UNROLL := 2
$(obj)/neon2.c: $(src)/neon.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_neon4.o += $(NEON_FLAGS)
targets += neon4.c
$(obj)/neon4.c: UNROLL := 4
$(obj)/neon4.c: $(src)/neon.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
CFLAGS_neon8.o += $(NEON_FLAGS)
targets += neon8.c
$(obj)/neon8.c: UNROLL := 8
$(obj)/neon8.c: $(src)/neon.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
targets += s390vx8.c
$(obj)/s390vx8.c: UNROLL := 8
$(obj)/s390vx8.c: $(src)/s390vx.uc $(src)/unroll.awk FORCE
$(call if_changed,unroll)
quiet_cmd_mktable = TABLE $@
cmd_mktable = $(obj)/mktables > $@
targets += tables.c
$(obj)/tables.c: $(obj)/mktables FORCE
$(call if_changed,mktable)