Initial effort at adding profiling support.

1 files changed, 54 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/i386/mcount.S b/libc/sysdeps/linux/i386/mcount.S
new file mode 100644
index 000000000..704a7b851
--- /dev/null
+++ b/libc/sysdeps/linux/i386/mcount.S
@@ -0,0 +1,54 @@
+/* i386-specific implemetation of profiling support.
+   Copyright (C) 1997, 2002 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 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.  */
+
+
+/* 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.  */
+
+        .globl _mcount
+	.type _mcount,@function;
+	.align 1<<4
+_mcount:
+	/* Save the caller-clobbered registers.  */
+	pushl %eax
+	pushl %ecx
+	pushl %edx
+
+	movl 12(%esp), %edx
+	movl 4(%ebp), %eax
+
+	/* No need to access the PLT or GOT, __mcount_internal is an
+	   internal function and we can make a relative call.  */
+	call __mcount_internal
+
+	/* Pop the saved registers.  Please note that `mcount' has no
+	   return value.  */
+	popl %edx
+	popl %ecx
+	popl %eax
+	ret
+	.size _mcount,.-_mcount;
+
+#undef mcount
+.weak mcount ; mcount = _mcount