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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
..
ABI f2fs-for-4.21-rc1 2018-12-31 09:41:37 -08:00
accelerators
accounting psi: cgroup support 2018-10-26 16:26:32 -07:00
acpi
admin-guide A handful of late-arriving documentation fixes. 2019-01-05 18:35:02 -08:00
aoe
arm ARM: 8833/1: Ensure that NEON code always compiles with Clang 2019-02-12 15:20:09 +00:00
arm64 arm64 festive updates for 4.21 2018-12-25 17:41:56 -08:00
auxdisplay
backlight
block block: update sysfs documentation 2018-12-16 19:53:06 -07:00
blockdev zram: writeback throttle 2018-12-28 12:11:49 -08:00
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-08-07 11:02:05 -07:00
bus-devices
cdrom Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
cgroup-v1 Merge branch 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2018-10-25 17:15:46 -07:00
cma
connector
console Documentation: corrections to console/console.txt 2018-08-10 16:09:40 -06:00
core-api A handful of late-arriving documentation fixes. 2019-01-05 18:35:02 -08:00
cpu-freq Documentation: cpu-freq: Frequencies aren't always sorted 2018-11-07 13:29:04 +01:00
cpuidle Documentation: admin-guide: PM: Add cpuidle document 2018-12-03 10:03:36 +01:00
crypto crypto: skcipher - remove remnants of internal IV generators 2018-12-23 11:52:45 +08:00
dev-tools A fairly normal cycle for documentation stuff. We have a new 2018-12-29 11:21:49 -08:00
device-mapper Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
devicetree hwspinlock updates for v4.21 2019-01-06 11:37:44 -08:00
doc-guide doc:process: add links where missing 2018-12-06 10:21:19 -07:00
driver-api pci-v4.21-changes 2019-01-05 17:57:34 -08:00
driver-model dma-mapping: remove dmam_{declare,release}_coherent_memory 2019-01-04 09:03:17 +01:00
early-userspace Correct gen_init_cpio tool's documentation 2018-11-25 12:25:53 -07:00
EDID Docs/EDID: Calculate CRC while building the code 2018-11-06 07:36:22 -07:00
extcon
fault-injection
fb This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
features Xtensa updates for v4.21: 2018-12-29 09:40:40 -08:00
filesystems Add Adiantum support for fscrypt 2019-01-06 12:21:11 -08:00
firmware_class
fmc Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
fpga
gpio Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
gpu A fairly normal cycle for documentation stuff. We have a new 2018-12-29 11:21:49 -08:00
hid HID: doc: fix wrong data structure reference for UHID_OUTPUT 2018-12-18 14:55:22 +01:00
hwmon hwmon: Introduce SENSOR_DEVICE_ATTR_{RO, RW, WO} and variants 2018-12-16 15:13:22 -08:00
i2c i2c: add i2c bus driver for NVIDIA GPU 2018-11-09 17:46:43 +01:00
ia64
ide Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
iio
infiniband
input Input: add REL_WHEEL_HI_RES and REL_HWHEEL_HI_RES 2018-12-07 16:27:11 +01:00
ioctl seccomp: add a return code to trap to userspace 2018-12-11 16:28:41 -08:00
isdn Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
kbuild kbuild: generate asm-generic wrappers if mandatory headers are missing 2019-01-06 09:46:51 +09:00
kdump
kernel-hacking
laptops platform-drivers-x86 for v4.20-1 2018-11-01 08:42:21 -07:00
leds Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
lightnvm
livepatch
locking This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
m68k Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
maintainer
md
media A fairly normal cycle for documentation stuff. We have a new 2018-12-29 11:21:49 -08:00
memory-devices
mic
mips Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
misc-devices
mmc Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
mtd Documentation: mtd: remove stale pxa3xx NAND controller documentation 2018-09-04 23:37:38 +02:00
namespaces
netlabel Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
networking Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-01-03 12:53:47 -08:00
nfc
nios2
nvdimm libnvdimm/security: Add documentation for nvdimm security support 2018-12-21 12:44:41 -08:00
nvmem Documentation: nvmem: document cell tables and lookup entries 2018-09-28 15:14:54 +02:00
openrisc
parisc Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
PCI pci-v4.20-changes 2018-10-25 06:50:48 -07:00
pcmcia pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function 2018-08-18 12:30:42 -07:00
perf Documentation: perf: Add documentation for ThunderX2 PMU uncore driver 2018-12-06 12:29:47 +00:00
phy
platform
power Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
powerpc powerpc/fadump: Reservationless firmware assisted dump 2018-12-21 11:32:49 +11:00
pps
process docs: fix Co-Developed-by docs 2019-01-04 13:13:48 -08:00
pti
ptp
rapidio
RCU doc: Fix "struction" typo in RCU memory-ordering documentation 2018-11-12 08:56:25 -08:00
riscv
s390 Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
scheduler This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
scsi SCSI misc on 20181224 2018-12-28 14:48:06 -08:00
security Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-01-02 09:43:14 -08:00
serial Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
sh sh: remove board_time_init() callback 2018-12-18 16:13:04 +01:00
sound Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
sparc
sphinx
sphinx-static docs: improve readability for people with poorer eyesight 2018-10-07 09:16:50 -06:00
spi Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
sysctl kernel/sysctl: add panic_print into sysctl 2019-01-04 13:13:47 -08:00
target
thermal Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
timers Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
trace Tracing changes for v4.21: 2018-12-31 11:46:59 -08:00
translations doc🇮🇹 add some process/* translations 2018-12-06 10:11:40 -07:00
usb Documentation/usb: Fix typo 2018-11-26 16:56:34 +01:00
userspace-api Merge branch 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-01-02 09:48:13 -08:00
virtual x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID 2018-12-14 17:59:54 +01:00
vm A fairly normal cycle for documentation stuff. We have a new 2018-12-29 11:21:49 -08:00
w1 Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
watchdog watchdog: docs: kernel-api: don't reference removed functions 2018-12-24 13:15:06 +01:00
wimax
x86 A fairly normal cycle for documentation stuff. We have a new 2018-12-29 11:21:49 -08:00
xilinx Documentation: xilinx: Add documentation for eemi APIs 2018-10-09 13:26:05 +02:00
xtensa
.gitignore
atomic_bitops.txt
atomic_t.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
Changes
clearing-warn-once.txt
CodingStyle
conf.py This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt dma-mapping: deprecate dma_zalloc_coherent 2018-12-20 08:14:09 +01:00
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf
dontdiff
efi-stub.txt efi_stub: update documentation on dtb= parameter 2018-09-09 14:46:44 -06:00
eisa.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt
highuid.txt
hw_random.txt
hwspinlock.txt
index.rst docs: tidy up TOCs and refs to license-rules.rst 2018-08-31 16:50:50 -06:00
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
isa.txt
isapnp.txt
kernel-per-CPU-kthreads.txt doc: Update removal of RCU-bh/sched update machinery 2018-08-30 10:59:48 -07:00
kobject.txt kref/kobject: Improve documentation 2018-12-06 13:57:03 +01:00
kprobes.txt
kref.txt
ldm.txt
lockup-watchdogs.txt
logo.gif
logo.txt
lsm.txt
lzo.txt
mailbox.txt
Makefile kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
memory-barriers.txt Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
men-chameleon-bus.txt
nommu-mmap.txt
ntb.txt
numastat.txt
padata.txt
parport-lowlevel.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pnp.txt
preempt-locking.txt Documentation: preempt-locking: Use better example 2018-10-12 11:35:47 -06:00
pwm.txt
rbtree.txt
remoteproc.txt
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt
SAK.txt
sgi-ioc4.txt
siphash.txt
SM501.txt
smsc_ece1099.txt
speculation.txt
static-keys.txt Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
SubmittingPatches
svga.txt
switchtec.txt NTB: switchtec_ntb: Update switchtec documentation with prerequisites for NTB 2018-10-11 11:28:53 -05:00
sync_file.txt
tee.txt
this_cpu_ops.txt
unaligned-memory-access.txt
vfio-mediated-device.txt
vfio.txt
video-output.txt
xillybus.txt
xz.txt
zorro.txt