powerpc: Add HWCAP3/HWCAP4 data to TCB for Power Architecture.

This patch adds a new feature for powerpc.  In order to get faster
access to the HWCAP3/HWCAP4 masks, similar to HWCAP/HWCAP2 (i.e. for
implementing __builtin_cpu_supports() in GCC) without the overhead of
reading them from the auxiliary vector, we now reserve space for them
in the TCB.

This is an ABI change for GLIBC 2.39.

Suggested-by: Peter Bergner <bergner@linux.ibm.com>
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-start.c b/sysdeps/unix/sysv/linux/powerpc/libc-start.c
index a4705daf1c..6a00cd88cd 100644
--- a/sysdeps/unix/sysv/linux/powerpc/libc-start.c
+++ b/sysdeps/unix/sysv/linux/powerpc/libc-start.c
@@ -87,6 +87,12 @@ __libc_start_main_impl (int argc, char **argv,
       case AT_HWCAP2:
 	_dl_hwcap2 = (unsigned long int) av->a_un.a_val;
 	break;
+      case AT_HWCAP3:
+	_dl_hwcap3 = (unsigned long int) av->a_un.a_val;
+	break;
+      case AT_HWCAP4:
+	_dl_hwcap4 = (unsigned long int) av->a_un.a_val;
+	break;
       case AT_PLATFORM:
 	_dl_platform = (void *) av->a_un.a_val;
 	break;