Make __aarch64_cpu_features unconditionally available. This permits the
unconditional use of this global inside __arm_get_current_vg, which was
introduced in r16-7637-g41b4a73f370116.
For now this global is only initialised when <sys/auxv.h> is available,
but we can extend this in future to support other ways of initialising
the bits used for SME support, and use this remove __aarch64_have_sme.
This approach was recently adopted by LLVM.
This patch does introduce an inconsistency with __aarch64_have_sme when
<sys/auxv.h> is unavailable. However, this doesn't introduce any
regressions, because one of the following conditions will hold:
1. SVE is enabled at compile time whenever we use a streaming or
streaming compatible function. In this case the compiler won't need to
use __arm_get_current_vg, so it doesn't matter if it gives the wrong
answer.
2. There is a use of a streaming or streaming compatible function when
we don't know whether SVE is enabled. In order to get correct DWARF
unwind information, we then have to be able to test for SVE availability
at runtime. This isn't possible until a working __arm_get_current_vg
implementation is available, so the configuration has never (yet) been
supported.
libgcc/ChangeLog:
PR target/124333
* config/aarch64/cpuinfo.c: Define __aarch64_cpu_features
unconditionally.
---
Evgeny/Saurabh: Can you confirm that this does fix the mingw build?
Is this ok for master?
Thanks, and sorry for the breakage,
Alice
diff --git a/libgcc/config/aarch64/cpuinfo.c b/libgcc/config/aarch64/cpuinfo.c
index
849c67fdc3b97d77079b1930429e730f0f50ed05..93d9491f7a488e7da890d9f3f942e1c5cc4bf834
100644
--- a/libgcc/config/aarch64/cpuinfo.c
+++ b/libgcc/config/aarch64/cpuinfo.c
@@ -24,6 +24,13 @@
#include "common/config/aarch64/cpuinfo.h"
+/* Architecture features used in Function Multi Versioning, and also in some
+ SME support routines. */
+struct {
+ unsigned long long features;
+ /* As features grows new fields could be added. */
+} __aarch64_cpu_features __attribute__((visibility("hidden"), nocommon));
+
#if __has_include(<sys/auxv.h>)
#include <sys/auxv.h>
@@ -40,12 +47,6 @@ typedef struct __ifunc_arg_t {
unsigned long _hwcap4;
} __ifunc_arg_t;
-/* Architecture features used in Function Multi Versioning. */
-struct {
- unsigned long long features;
- /* As features grows new fields could be added. */
-} __aarch64_cpu_features __attribute__((visibility("hidden"), nocommon));
-
#define _IFUNC_ARG_HWCAP (1ULL << 62)
#define AT_HWCAP 16
#define AT_HWCAP2 26
