ARM NEON code in Xcode Project - iOS

I'm trying to run NEON code in my Xcode project for school purposes. I'm using Xcode 7, LLVM 7.0 and using a device to execute the program.

I have a .s file in the project with the code. If I run just ARM code it works perfectly, but when I add a single NEON line of code (like in the code snippet) I get the following message:

AssemblyTest.s:22:5: error: unrecognized instruction mnemonic
    vmul.f32 q14, q8, q8
    ^

The test code I'm using is

.globl  _addInts
.align  2

_addInts:
.cfi_startproc
sub sp, sp, #16

str w0, [sp, #12]
str w1, [sp, #8]

add  w0, w0, w1
add sp, sp, #16

vmul.f32 q14, q8, q8 // --- This is the NEON line

ret

.cfi_endproc

Is there any compiler flag I should add to the project? Does LLVM support NEON instructions set?

Thanks!!

Solution

As Notlikethat points out you're mixing AArch32 and AArch64.. For example vmul.f32 qx,qy,qz (AArch32) is performing a two float multiply from 64 bit Q registers. While fmul vx.4s,vy.4s,vz.4s (AArch64) is performing 4 float multiplies from 128 bit V registers.

You can mix both architectures in a project by separating them using #ifdefs:

#ifdef __arm__ //AArch32
#ifdef __arm64__ //AArch64

Compile the following using architecture: arm64 in xcode and you're OK. You need to modify the fmul to something useful ;)

sub sp, sp, #16
str w0, [sp, #12]
str w1, [sp, #8]
add  w0, w0, w1
add sp, sp, #16
fmul v14.4s, v8.4s, v9.4s

Good luck.