powerpc64le: Add glibc-hwcaps support

The "power10" and "power9" subdirectories are selected in a way
that matches the -mcpu=power10 and -mcpu=power9 options of GCC.

elf/Makefile

@@ -1832,7 +1832,7 @@ $(objpfx)argv0test.out: tst-rtld-argv0.sh $(objpfx)ld.so \
 # glibc-hwcaps mechanism for this architecture).  Used to obtain test
 # coverage for some glibc-hwcaps tests for the widest possible range
 # of systems.
-glibc-hwcaps-first-subdirs-for-tests = x86-64-v2
+glibc-hwcaps-first-subdirs-for-tests = power9 x86-64-v2
 
 # The test modules are parameterized by preprocessor macros.
 LDFLAGS-libmarkermod1-1.so += -Wl,-soname,libmarkermod1.so

elf/tst-glibc-hwcaps-cache.script

@@ -5,6 +5,12 @@ cp $B/elf/libmarkermod2-1.so $L/libmarkermod2.so
 cp $B/elf/libmarkermod3-1.so $L/libmarkermod3.so
 cp $B/elf/libmarkermod4-1.so $L/libmarkermod4.so
 
+mkdirp 0770 $L/glibc-hwcaps/power9
+cp $B/elf/libmarkermod2-2.so $L/glibc-hwcaps/power9/libmarkermod2.so
+mkdirp 0770 $L/glibc-hwcaps/power10
+cp $B/elf/libmarkermod3-2.so $L/glibc-hwcaps/power9/libmarkermod3.so
+cp $B/elf/libmarkermod3-3.so $L/glibc-hwcaps/power10/libmarkermod3.so
+
 mkdirp 0770 $L/glibc-hwcaps/x86-64-v2
 cp $B/elf/libmarkermod2-2.so $L/glibc-hwcaps/x86-64-v2/libmarkermod2.so
 mkdirp 0770 $L/glibc-hwcaps/x86-64-v3

sysdeps/powerpc/powerpc64/le/Makefile

@@ -188,3 +188,31 @@ ifeq ($(subdir),nptl)
 CFLAGS-tst-thread_local1.cc += -mno-float128
 CFLAGS-tst-minstack-throw.cc += -mno-float128
 endif
+
+ifeq ($(subdir),elf)
+$(objpfx)tst-glibc-hwcaps: \
+  $(objpfx)libmarkermod2-1.so $(objpfx)libmarkermod3-1.so
+$(objpfx)tst-glibc-hwcaps.out: \
+  $(objpfx)libmarkermod2.so \
+    $(objpfx)glibc-hwcaps/power9/libmarkermod2.so \
+  $(objpfx)libmarkermod3.so \
+    $(objpfx)glibc-hwcaps/power9/libmarkermod3.so \
+    $(objpfx)glibc-hwcaps/power10/libmarkermod3.so \
+
+$(objpfx)glibc-hwcaps/power9/libmarkermod2.so: $(objpfx)libmarkermod2-2.so
+	$(make-target-directory)
+	cp $< $@
+$(objpfx)glibc-hwcaps/power9/libmarkermod3.so: $(objpfx)libmarkermod3-2.so
+	$(make-target-directory)
+	cp $< $@
+$(objpfx)glibc-hwcaps/power10/libmarkermod3.so: $(objpfx)libmarkermod3-3.so
+	$(make-target-directory)
+	cp $< $@
+
+ifeq (no,$(build-hardcoded-path-in-tests))
+# This is an ld.so.cache test, and RPATH/RUNPATH in the executable
+# interferes with its test objectives.
+tests-container += tst-glibc-hwcaps-cache
+endif
+
+endif # $(subdir) == elf

sysdeps/powerpc/powerpc64/le/dl-hwcaps-subdirs.c

@@ -0,0 +1,46 @@
+/* Architecture-specific glibc-hwcaps subdirectories.  powerpc64le version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <dl-hwcaps.h>
+#include <ldsodefs.h>
+
+const char _dl_hwcaps_subdirs[] = "power10:power9";
+enum { subdirs_count = 2 }; /* Number of components in _dl_hwcaps_subdirs.  */
+
+uint32_t
+_dl_hwcaps_subdirs_active (void)
+{
+  int active = 0;
+
+  /* Test in reverse preference order.  Altivec and VSX are implied by
+     the powerpc64le ABI definition.  */
+
+  /* POWER9.  GCC enables float128 hardware support for -mcpu=power9.  */
+  if ((GLRO (dl_hwcap2) & PPC_FEATURE2_ARCH_3_00) == 0
+      || (GLRO (dl_hwcap2) & PPC_FEATURE2_HAS_IEEE128) == 0)
+    return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
+  ++active;
+
+  /* POWER10.  GCC defines __MMA__ for -mcpu=power10.  */
+  if ((GLRO (dl_hwcap2) & PPC_FEATURE2_ARCH_3_1) == 0
+      || (GLRO (dl_hwcap2) & PPC_FEATURE2_MMA) == 0)
+    return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
+  ++active;
+
+  return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
+}

sysdeps/powerpc/powerpc64/le/tst-glibc-hwcaps.c

@@ -0,0 +1,54 @@
+/* glibc-hwcaps subdirectory test.  powerpc64le version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <string.h>
+#include <support/check.h>
+#include <sys/auxv.h>
+#include <sys/param.h>
+
+extern int marker2 (void);
+extern int marker3 (void);
+
+/* Return the POWER level, 8 for the baseline.  */
+static int
+compute_level (void)
+{
+  const char *platform = (const char *) getauxval (AT_PLATFORM);
+  if (strcmp (platform, "power8") == 0)
+    return 8;
+  if (strcmp (platform, "power9") == 0)
+    return 9;
+  if (strcmp (platform, "power10") == 0)
+    return 10;
+  printf ("warning: unrecognized AT_PLATFORM value: %s\n", platform);
+  /* Assume that the new platform supports POWER10.  */
+  return 10;
+}
+
+static int
+do_test (void)
+{
+  int level = compute_level ();
+  printf ("info: detected POWER level: %d\n", level);
+  TEST_COMPARE (marker2 (), MIN (level - 7, 2));
+  TEST_COMPARE (marker3 (), MIN (level - 7, 3));
+  return 0;
+}
+
+#include <support/test-driver.c>