gcc 11.3.0 on macOS/Apple Silicon and SHA-3 instructions-CodePudding

I have gcc 11.3.0 installed using Homebrew on a MacBook Air with Apple Silicon M1 CPU. The binary is the aarch64 native version, not Rosetta emulated. The installed OS is macOS Monterey 12.3.

I'm having an issue compiling a program which uses the ARMv8.2-A SHA-3 extension instructions, which are supported by the M1 CPU. This is a minimal reproducible example:

#include <arm_neon.h>

int main() {
    uint64x2_t a = {0}, b = {0}, c = {0};
    veor3q_u64(a, b, c);
    return 0;
}

This code compiles just fine with the Apple supplied clang compiler.

I compiled it using the following command line for gcc 11:

gcc-11 -o test test.c -march=armv8-a sha3

This results in the following error:

In file included from test.c:1:
test.c: In function 'main':
/opt/homebrew/Cellar/gcc/11.3.0/lib/gcc/11/gcc/aarch64-apple-darwin21/11/include/arm_neon.h:32320:1: error: inlining failed in call to 'always_inline' 'veor3q_u64': target specific option mismatch
32320 | veor3q_u64 (uint64x2_t __a, uint64x2_t __b, uint64x2_t __c)
      | ^~~~~~~~~~
test.c:5:5: note: called from here
    5 |     veor3q_u64(a, b, c);
      |     ^~~~~~~~~~~~~~~~~~~

Is this a bug in this particular hardware/software combination, or is there some command-line option I can pass to gcc to make this particular program compile?

CodePudding user response：

Solved the problem. It turns out that gcc requires -march=armv8.2-a sha3 rather than just -march=armv8-a sha3 to compile this intrinsic. Indeed, in gcc's version of arm_neon.h, one can find this right before the block of intrinsics which includes veor3q_u64:

#pragma GCC target ("arch=armv8.2-a sha3")