de9c0d49d8
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> |
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.. | ||
boot | ||
common | ||
configs | ||
crypto | ||
firmware | ||
include | ||
kernel | ||
kvm | ||
lib | ||
mach-actions | ||
mach-alpine | ||
mach-artpec | ||
mach-asm9260 | ||
mach-aspeed | ||
mach-at91 | ||
mach-axxia | ||
mach-bcm | ||
mach-berlin | ||
mach-clps711x | ||
mach-cns3xxx | ||
mach-davinci | ||
mach-digicolor | ||
mach-dove | ||
mach-ebsa110 | ||
mach-efm32 | ||
mach-ep93xx | ||
mach-exynos | ||
mach-footbridge | ||
mach-gemini | ||
mach-highbank | ||
mach-hisi | ||
mach-imx | ||
mach-integrator | ||
mach-iop13xx | ||
mach-iop32x | ||
mach-iop33x | ||
mach-ixp4xx | ||
mach-keystone | ||
mach-ks8695 | ||
mach-lpc18xx | ||
mach-lpc32xx | ||
mach-mediatek | ||
mach-meson | ||
mach-mmp | ||
mach-moxart | ||
mach-mv78xx0 | ||
mach-mvebu | ||
mach-mxs | ||
mach-netx | ||
mach-nomadik | ||
mach-npcm | ||
mach-nspire | ||
mach-omap1 | ||
mach-omap2 | ||
mach-orion5x | ||
mach-oxnas | ||
mach-picoxcell | ||
mach-prima2 | ||
mach-pxa | ||
mach-qcom | ||
mach-rda | ||
mach-realview | ||
mach-rockchip | ||
mach-rpc | ||
mach-s3c24xx | ||
mach-s3c64xx | ||
mach-s5pv210 | ||
mach-sa1100 | ||
mach-shmobile | ||
mach-socfpga | ||
mach-spear | ||
mach-sti | ||
mach-stm32 | ||
mach-sunxi | ||
mach-tango | ||
mach-tegra | ||
mach-u300 | ||
mach-uniphier | ||
mach-ux500 | ||
mach-versatile | ||
mach-vexpress | ||
mach-vt8500 | ||
mach-w90x900 | ||
mach-zx | ||
mach-zynq | ||
mm | ||
net | ||
nwfpe | ||
oprofile | ||
plat-iop | ||
plat-omap | ||
plat-orion | ||
plat-pxa | ||
plat-samsung | ||
plat-versatile | ||
probes | ||
tools | ||
vdso | ||
vfp | ||
xen | ||
Kconfig | ||
Kconfig-nommu | ||
Kconfig.debug | ||
Makefile |