ix86 specific mcount entry point which preserves all registers.

1 files changed, 65 insertions, 0 deletions

diff --git a/sysdeps/i386/i386-mcount.S b/sysdeps/i386/i386-mcount.S
new file mode 100644
index 0000000000..60d52e98fa
--- /dev/null
+++ b/sysdeps/i386/i386-mcount.S
@@ -0,0 +1,65 @@
+/* i386-specific implemetation of profiling support.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <sysdep.h>
+
+/* We need a special version of the `mcount' function since for ix86 it
+   must not clobber any register.  This has several reasons:
+     - there is a bug in gcc as of version 2.7.2.2 which prohibits the
+       use of profiling together with nested functions
+     - the ELF `fixup' function uses GCC's regparm feature
+     - some (future) systems might want to pass parameters in registers.  */
+
+	ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(_mcount)
+	ASM_TYPE_DIRECTIVE(C_SYMBOL_NAME(_mcount), @function)
+	.align ALIGNARG(4)
+C_LABEL(_mcount)
+	/* Save the caller-clobbered registers.  */
+	pushl %eax
+	pushl %ecx
+	pushl %edx
+
+	movl 12(%esp), %eax
+	movl 4(%ebp), %ecx
+	pushl %eax
+	pushl %ecx
+
+#ifdef PIC
+	call 1f
+1:	popl %ecx
+	addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %ecx
+	movl C_SYMBOL_NAME(__mcount_internal@GOTOFF)(%ecx), %eax
+	call *%eax
+#else
+	call C_SYMBOL_NAME(__mcount_internal)
+#endif
+	popl %ecx
+	popl %eax	/* Pop the parameters.  */
+
+	/* Pop the saved registers.  Please note that `mcount' has no
+	   return value.  */
+	popl %edx
+	popl %ecx
+	popl %eax
+	ret
+	ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(_mcount))
+
+#undef mcount
+weak_alias(_mcount, mcount)