From: Will Schmidt <will_schmidt@vnet.ibm.com>
To: libc-ports@sourceware.org
Cc: willschm@us.ibm.com
Subject: [PATCH] Powerpc: Use and override SETUP_GOT_ACCESS for ppc476
Date: Mon, 21 Nov 2011 21:25:00 -0000 [thread overview]
Message-ID: <1321910448.3416.27.camel@brimstone> (raw)
Hi,
This follows changes made in glibc (Subject "simplify code for
accessing the powerpc GOT"), which provides a simplified method
for accessing the powerpc GOT, and a way to override that access for
sub architectures. This code provides a version of SETUP_GOT_ACCESS
that is suitable for the ppc476 architecture, and overrides the
ppc_got() function to match that instruction sequence.
2011-11-21 Will Schmidt <will_schmidt@vnet.ibm.com>
* sysdeps/powerpc/powerpc32/476/dl-machine.h: New file. Add a
ppc_got_476 function.
* sysdeps/powerpc/powerpc32/476/sysdep.h: New file. Define the
SETUP_GOT_ACCESS macro for the 476 architecture.
diff --git a/sysdeps/powerpc/powerpc32/476/dl-machine.h b/sysdeps/powerpc/powerpc32/476/dl-machine.h
new file mode 100644
index 0000000..5470bae
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/476/dl-machine.h
@@ -0,0 +1,45 @@
+/* Machine-dependent ELF dynamic relocation inline functions. PowerPC version.
+ Copyright (C) 1995-2002, 2003, 2005, 2006, 2011
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <sysdeps/powerpc/powerpc32/dl-machine.h>
+
+#ifndef PPC_GOT_476_OVERRIDE
+#define PPC_GOT_476_OVERRIDE
+
+/* Return the value of the GOT pointer. */
+static inline Elf32_Addr * __attribute__ ((const))
+ppc_got_476 (void)
+{
+ Elf32_Addr *got;
+
+ asm (" bl $+8 \n"
+ "1: \n"
+ " b $+8 \n"
+ " blr \n"
+ " mflr %0 \n"
+ " addis %0,%0,_GLOBAL_OFFSET_TABLE_-1b@ha\n"
+ " addi %0,%0,_GLOBAL_OFFSET_TABLE_-1b@l\n"
+ : "=b" (got) : : "lr");
+
+ return got;
+}
+#define ppc_got() ppc_got_476()
+
+#endif /* PPC_GOT_476_OVERRIDE */
diff --git a/sysdeps/powerpc/powerpc32/476/sysdep.h b/sysdeps/powerpc/powerpc32/476/sysdep.h
new file mode 100644
index 0000000..2240207
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/476/sysdep.h
@@ -0,0 +1,45 @@
+/* Assembly macros for 32-bit PowerPC.
+ Copyright (C) 1999, 2001, 2002, 2003, 2006, 2011
+ 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, write to the Free
+ Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA
+ 02110-1301 USA. */
+
+#include <sysdeps/powerpc/powerpc32/sysdep.h>
+#include <sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h>
+
+#ifdef __ASSEMBLER__
+
+#ifdef __ELF__
+
+/* helper macro for accessing the 32-bit powerpc GOT. */
+#ifndef ACCESS_GOT_476
+#define ACCESS_GOT_476
+
+#undef SETUP_GOT_ACCESS
+
+#define SETUP_GOT_ACCESS(regname) \
+ bl $+8 ; \
+1: ; \
+ b $+8 ; \
+ blr ; \
+ mflr (regname)
+
+#endif /* ACCESS_GOT_476 */
+
+#endif /* __ELF__ */
+
+#endif /* __ASSEMBLER__ */
next reply other threads:[~2011-11-21 21:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-21 21:25 Will Schmidt [this message]
2012-01-05 15:57 ` [PATCH v2] " Will Schmidt
2012-06-13 21:41 ` Will Schmidt
2012-06-15 13:46 ` Ryan S. Arnold
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