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iosllvmxcode5neonarm64

Unknown register name "q0" in asm (arm64)

I'm currently trying to compile my lib for the new arm64 arch. I have a bunch of NEON assembly and for all of them I receive an error

Unknown register name "q0" in asm.

Even if I write smth simple as this:

asm (
     ""
     :
     :
     : "q0", "q1", "q2", "q3"
     );

I thought arm64 supports NEON. Am i missing something ?

Solution

  • “v0”:

    scanon$ cat bar.c
int foo(void) {
  __asm__("":::"q0");
  return 0;
}
scanon$ xcrun -sdk iphoneos clang bar.c -arch arm64 -c
bar.c:2:16: error: unknown register name 'q0' in asm
  __asm__("":::"q0");
               ^
1 error generated.
scanon$ cat foo.c
int foo(void) {
  __asm__("":::"v0");
  return 0;
}
scanon$ xcrun -sdk iphoneos clang foo.c -arch arm64 -c
scanon$

    arm64 is a new ISA. The actual NEON instructions and register layout are entirely new. You will need to re-write or adapt assembly code for the new architecture.