On 23/07/2025 09:45, Yury Khrustalev wrote:
gcc/testsuite/ChangeLog:
* g++.target/aarch64/mv-cpu-features.C: new test.
---
.../g++.target/aarch64/mv-cpu-features.C | 65 +++++++++++++++++++
1 file changed, 65 insertions(+)
create mode 100644 gcc/testsuite/g++.target/aarch64/mv-cpu-features.C
diff --git a/gcc/testsuite/g++.target/aarch64/mv-cpu-features.C
b/gcc/testsuite/g++.target/aarch64/mv-cpu-features.C
new file mode 100644
index 00000000000..00a0cf1ecc4
--- /dev/null
+++ b/gcc/testsuite/g++.target/aarch64/mv-cpu-features.C
@@ -0,0 +1,65 @@
+/* { dg-do run } */
+/* { dg-require-ifunc "" } */
+/* { dg-options "-Wno-experimental-fmv-target" } */
+
+#include <cstdint>
+#include <sys/auxv.h>
+
+__attribute__((target_version ("default")))
+int foo ()
+{
+ return 0;
+}
+
+__attribute__((target_version ("rng")))
+int foo ()
+{
+ return 1;
+}
+
+__attribute__((target_version ("lse")))
+int foo ()
+{
+ return 2;
+}
+
+typedef struct {
+ uint64_t size;
+ uint64_t hwcap;
+ uint64_t hwcap2;
+ uint64_t hwcap3;
+ uint64_t hwcap4;
+} ifunc_arg_t;
+
+int impl ()
+{
+ return 0;
+}
+
+#ifndef _IFUNC_ARG_HWCAP
+#define _IFUNC_ARG_HWCAP (1ULL << 62)
+#endif
+
+extern "C" void
+__init_cpu_features_resolver (unsigned long hwcap, const ifunc_arg_t *arg);
+
+extern "C" void *
+fun_resolver (uint64_t a0, const ifunc_arg_t *a1)
+{
+ ifunc_arg_t arg = {};
+ arg.size = sizeof (ifunc_arg_t);
+ arg.hwcap = HWCAP_ATOMICS;
+ arg.hwcap2 = HWCAP2_RNG;
+ __init_cpu_features_resolver (arg.hwcap | _IFUNC_ARG_HWCAP, &arg);
+ return (void *)(uintptr_t)impl;
+}
+
+extern "C" int fun (void) __attribute__((ifunc ("fun_resolver")));
+
+int main ()
+{
+ int res = fun ();
+ if (res == 0 && foo () == 2)
+ return 0;
Hi Yury,
The FMV part of this test doesn't seem quite right.
For FMV it is using the auto-generated resolver, which will use
__init_cpu_features_resolver and get a real read on the host's arch.
This test then seems to check that the lse version is selected. So it
seems like this would only work on systems with lse?
The ifunc part looks good to my eye.
Thanks,
Alfie
+ return 1;
+}
