iOS 11 - Xcode 9.0 Beta 3 error: Use of undeclared identifier 'vabs_s8'

Question

Xcode gives me this weird error: Use of undeclared identifier 'vabs_s8'

File path: /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.0.sdk/usr/include/simd/common.h

This file is included by GameKit framework: GameKit.h => simd.h => vector.h => common.h

Any suggestions how to fix this?

did you add any third party framework in project ? – KKRocks Jul 17 '17 at 13:12 — KKRocks, Jul 17 '17 at 13:12
No, it compiles on Xcode 8.3.3 but not on Xcode 9 - beta. – fmor Jul 17 '17 at 13:14 — fmor, Jul 17 '17 at 13:14

score 0 · Answer 1 · answered Feb 21 '18 at 16:35

0

This error is to do with the architecture your targeting. A simple workaround is to place these at the top of common.h file.

#undef arm64 #undef arm

answered Feb 21 '18 at 16:35

user3276251

11
3

score 0 · Answer 2 · answered Jun 22 '18 at 11:17

As you've noticed,gamekit includes simd/common.h in which ‘vabs_s8()’ function is undeclared.

Naturally, simd/common.h includes simd/base.h -> and -> simd/base.h includes arm_neon.h if ARM_NEON is defined. In arm_neon.h we have the declaration of ‘vabs_s8()’ function.

So if vabs_s8 is undeclared means the header is not included which means __ARM_NEON__ is not defined.

__ARM_NEON__ is enabled by default if you target armv7/arm64, so this means there might be something wrong with your project settings.

Solution: One of our programmers found out that adding "-mfpu=neon" in Other C Flags fixes this issue.

iOS 11 - Xcode 9.0 Beta 3 error: Use of undeclared identifier 'vabs_s8'

2 Answers2