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authorEric Andersen <andersen@codepoet.org>2003-03-03 20:58:42 +0000
committerEric Andersen <andersen@codepoet.org>2003-03-03 20:58:42 +0000
commit67eff66438688fddebe41f77fd252a3b2b135271 (patch)
tree18dbee3e9afe50d27095140198e2aa34df1de061 /libc/sysdeps/linux/i386/mcount.S
parent2229d0fa131387b9b8ad16ac88347350a080aeb5 (diff)
Initial effort at adding profiling support.
Diffstat (limited to 'libc/sysdeps/linux/i386/mcount.S')
-rw-r--r--libc/sysdeps/linux/i386/mcount.S54
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