xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/aarch64/sme-abi-init.c (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad)
1*5f757f3fSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
2*5f757f3fSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
3*5f757f3fSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
4*5f757f3fSDimitry Andric 
5*5f757f3fSDimitry Andric __attribute__((visibility("hidden"), nocommon))
6*5f757f3fSDimitry Andric _Bool __aarch64_has_sme_and_tpidr2_el0;
7*5f757f3fSDimitry Andric 
8*5f757f3fSDimitry Andric // We have multiple ways to check that the function has SME, depending on our
9*5f757f3fSDimitry Andric // target.
10*5f757f3fSDimitry Andric // * For Linux we can use __getauxval().
11*5f757f3fSDimitry Andric // * For newlib we can use __aarch64_sme_accessible().
12*5f757f3fSDimitry Andric 
13*5f757f3fSDimitry Andric #if defined(__linux__)
14*5f757f3fSDimitry Andric 
15*5f757f3fSDimitry Andric #ifndef AT_HWCAP2
16*5f757f3fSDimitry Andric #define AT_HWCAP2 26
17*5f757f3fSDimitry Andric #endif
18*5f757f3fSDimitry Andric 
19*5f757f3fSDimitry Andric #ifndef HWCAP2_SME
20*5f757f3fSDimitry Andric #define HWCAP2_SME (1 << 23)
21*5f757f3fSDimitry Andric #endif
22*5f757f3fSDimitry Andric 
23*5f757f3fSDimitry Andric extern unsigned long int __getauxval (unsigned long int);
24*5f757f3fSDimitry Andric 
25*5f757f3fSDimitry Andric static _Bool has_sme(void) {
26*5f757f3fSDimitry Andric   return __getauxval(AT_HWCAP2) & HWCAP2_SME;
27*5f757f3fSDimitry Andric }
28*5f757f3fSDimitry Andric 
29*5f757f3fSDimitry Andric #else  // defined(__linux__)
30*5f757f3fSDimitry Andric 
31*5f757f3fSDimitry Andric #if defined(COMPILER_RT_SHARED_LIB)
32*5f757f3fSDimitry Andric __attribute__((weak))
33*5f757f3fSDimitry Andric #endif
34*5f757f3fSDimitry Andric extern _Bool __aarch64_sme_accessible(void);
35*5f757f3fSDimitry Andric 
36*5f757f3fSDimitry Andric static _Bool has_sme(void)  {
37*5f757f3fSDimitry Andric #if defined(COMPILER_RT_SHARED_LIB)
38*5f757f3fSDimitry Andric   if (!__aarch64_sme_accessible)
39*5f757f3fSDimitry Andric     return 0;
40*5f757f3fSDimitry Andric #endif
41*5f757f3fSDimitry Andric   return __aarch64_sme_accessible();
42*5f757f3fSDimitry Andric }
43*5f757f3fSDimitry Andric 
44*5f757f3fSDimitry Andric #endif // defined(__linux__)
45*5f757f3fSDimitry Andric 
46*5f757f3fSDimitry Andric #if __GNUC__ >= 9
47*5f757f3fSDimitry Andric #pragma GCC diagnostic ignored "-Wprio-ctor-dtor"
48*5f757f3fSDimitry Andric #endif
49*5f757f3fSDimitry Andric __attribute__((constructor(90)))
50*5f757f3fSDimitry Andric static void init_aarch64_has_sme(void) {
51*5f757f3fSDimitry Andric   __aarch64_has_sme_and_tpidr2_el0 = has_sme();
52*5f757f3fSDimitry Andric }
53