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>

5 files changed, 14 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/dl-parse_auxv.h b/sysdeps/unix/sysv/linux/dl-parse_auxv.h
index e3d758b..ea2a58e 100644
--- a/sysdeps/unix/sysv/linux/dl-parse_auxv.h
+++ b/sysdeps/unix/sysv/linux/dl-parse_auxv.h
@@ -47,6 +47,8 @@ void _dl_parse_auxv (ElfW(auxv_t) *av, dl_parse_auxv_t auxv_values)
   GLRO(dl_platform) = (void *) auxv_values[AT_PLATFORM];
   GLRO(dl_hwcap) = auxv_values[AT_HWCAP];
   GLRO(dl_hwcap2) = auxv_values[AT_HWCAP2];
+  GLRO(dl_hwcap3) = auxv_values[AT_HWCAP3];
+  GLRO(dl_hwcap4) = auxv_values[AT_HWCAP4];
   GLRO(dl_clktck) = auxv_values[AT_CLKTCK];
   GLRO(dl_fpu_control) = auxv_values[AT_FPUCW];
   _dl_random = (void *) auxv_values[AT_RANDOM];
diff --git a/sysdeps/unix/sysv/linux/dl-sysdep.c b/sysdeps/unix/sysv/linux/dl-sysdep.c
index ad3692d..e1b14e9 100644
--- a/sysdeps/unix/sysv/linux/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/dl-sysdep.c
@@ -197,6 +197,8 @@ _dl_show_auxv (void)
 	  [AT_SYSINFO_EHDR - 2] =	{ "SYSINFO_EHDR:      0x", hex },
 	  [AT_RANDOM - 2] =		{ "RANDOM:            0x", hex },
 	  [AT_HWCAP2 - 2] =		{ "HWCAP2:            0x", hex },
+	  [AT_HWCAP3 - 2] =		{ "HWCAP3:            0x", hex },
+	  [AT_HWCAP4 - 2] =		{ "HWCAP4:            0x", hex },
 	  [AT_MINSIGSTKSZ - 2] =	{ "MINSIGSTKSZ:       ", dec },
 	  [AT_L1I_CACHESIZE - 2] =	{ "L1I_CACHESIZE:     ", dec },
 	  [AT_L1I_CACHEGEOMETRY - 2] =	{ "L1I_CACHEGEOMETRY: 0x", hex },
diff --git a/sysdeps/unix/sysv/linux/powerpc/cpu-features.c b/sysdeps/unix/sysv/linux/powerpc/cpu-features.c
index 8e8a5ec..a947d62 100644
--- a/sysdeps/unix/sysv/linux/powerpc/cpu-features.c
+++ b/sysdeps/unix/sysv/linux/powerpc/cpu-features.c
@@ -94,6 +94,8 @@ init_cpu_features (struct cpu_features *cpu_features, uint64_t hwcaps[])
      which are set by __tcb_parse_hwcap_and_convert_at_platform.  */
   cpu_features->hwcap = hwcaps[0];
   cpu_features->hwcap2 = hwcaps[1];
+  cpu_features->hwcap3 = hwcaps[2];
+  cpu_features->hwcap4 = hwcaps[3];
   /* Default is to use aligned memory access on optimized function unless
      tunables is enable, since for this case user can explicit disable
      unaligned optimizations.  */
diff --git a/sysdeps/unix/sysv/linux/powerpc/cpu-features.h b/sysdeps/unix/sysv/linux/powerpc/cpu-features.h
index 1294f0b..e9eb6a1 100644
--- a/sysdeps/unix/sysv/linux/powerpc/cpu-features.h
+++ b/sysdeps/unix/sysv/linux/powerpc/cpu-features.h
@@ -26,6 +26,8 @@ struct cpu_features
   bool use_cached_memopt;
   unsigned long int hwcap;
   unsigned long int hwcap2;
+  unsigned long int hwcap3;
+  unsigned long int hwcap4;
 };
 
 static const char hwcap_names[] = {
diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-start.c b/sysdeps/unix/sysv/linux/powerpc/libc-start.c
index a4705da..6a00cd8 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;