[glibc] powerpc64le: Check HWCAP bits against compiler build flags

[glibc] powerpc64le: Check HWCAP bits against compiler build flags

[Florian Weimer]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=d337345ce145e23c5f3a956f349d924fdf54ce2d

commit d337345ce145e23c5f3a956f349d924fdf54ce2d
Author: Florian Weimer <fweimer@redhat.com>
Date:   Wed May 19 11:09:57 2021 +0200

    powerpc64le: Check HWCAP bits against compiler build flags
    
    When built with GCC 11.1 and -mcpu=power9, ld.so prints this error
    message when running on POWER8:
    
    Fatal glibc error: CPU lacks ISA 3.00 support (POWER9 or later required)

Diff:
---
 sysdeps/powerpc/powerpc64/le/dl-hwcap-check.h | 52 +++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/sysdeps/powerpc/powerpc64/le/dl-hwcap-check.h b/sysdeps/powerpc/powerpc64/le/dl-hwcap-check.h
new file mode 100644
index 0000000000..0437ae4d52
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/le/dl-hwcap-check.h
@@ -0,0 +1,52 @@
+/* Check for hardware capabilities after HWCAP parsing.  powerpc64le version.
+   Copyright (C) 2021 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/>.  */
+
+#ifndef _DL_HWCAP_CHECK_H
+#define _DL_HWCAP_CHECK_H
+
+#include <ldsodefs.h>
+
+static inline void
+dl_hwcap_check (void)
+{
+#ifdef _ARCH_PWR9
+  if ((GLRO (dl_hwcap2) & PPC_FEATURE2_ARCH_3_00) == 0)
+    _dl_fatal_printf ("\
+Fatal glibc error: CPU lacks ISA 3.00 support (POWER9 or later required)\n");
+#endif
+#ifdef __FLOAT128_HARDWARE__
+  if ((GLRO (dl_hwcap2) & PPC_FEATURE2_HAS_IEEE128) == 0)
+    _dl_fatal_printf ("\
+Fatal glibc error: CPU lacks float128 support (POWER 9 or later required)\n");
+#endif
+   /* This check is not actually reached when building for POWER10 and
+      running on POWER9 because there are faulting PCREL instructions
+      before this point.  */
+#if defined _ARCH_PWR10 || defined __PCREL__
+  if ((GLRO (dl_hwcap2) & PPC_FEATURE2_ARCH_3_1) == 0)
+    _dl_fatal_printf ("\
+Fatal glibc error: CPU lacks ISA 3.10 support (POWER10 or later required)\n");
+#endif
+#ifdef __MMA__
+  if ((GLRO (dl_hwcap2) & PPC_FEATURE2_MMA) == 0)
+    _dl_fatal_printf ("\
+Fatal glibc error: CPU lacks MMA support (POWER10 or later required)\n");
+#endif
+}
+
+#endif /* _DL_HWCAP_CHECK_H */