x86-64 mcount implementation

1 files changed, 67 insertions, 0 deletions

diff --git a/sysdeps/x86_64/_mcount.S b/sysdeps/x86_64/_mcount.S
new file mode 100644
index 0000000000..c8fe441993
--- /dev/null
+++ b/sysdeps/x86_64/_mcount.S
@@ -0,0 +1,67 @@
+/* Machine-specific calling sequence for `mcount' profiling function.  x86-64 version.
+   Copyright (C) 2002 Free Software Foundation, Inc.
+   Contributed by Andreas Jaeger <aj@suse.de>.
+   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.  */
+
+/* Assembly stub to invoke _mcount().  Compiler generated code calls
+   this stub after executing a function's prologue and without saving any
+   registers.  It is therefore necessary to preserve %rcx, %rdx, %rsi, %rdi,
+   %r8, %r9 as they may contain function arguments.  */
+
+#include <sysdep.h>
+
+	ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(_mcount)
+	ASM_TYPE_DIRECTIVE(C_SYMBOL_NAME(_mcount), @function)
+	.align ALIGNARG(4)
+C_LABEL(_mcount)
+	/* Allocate space for 7 registers.  */
+	subq	$56,$rsp
+	movq	$rax,($rsp)
+	movq	%rcx,8($rsp)
+	movq	%rdx,16($rsp)
+	movq	%rsi,24($rsp)
+	movq	%rdi,32($rsp)
+	movq	%r8,40($rsp)
+	movq	%r9,48($rsp)
+
+	/* Setup parameter for __mcount_internal.  */
+	/* selfpc is the return address on the stack.  */
+	movq	48(%rsp),%rsi
+	/* Get frompc via the frame pointer.  */
+	movq	8(%rbp),%rdi
+#ifdef PIC
+	call C_SYMBOL_NAME(__mcount_internal)@PLT
+#else
+	call C_SYMBOL_NAME(__mcount_internal)
+#endif
+	/* Pop the saved registers.  Please note that `mcount' has no
+	   return value.  */
+	movq	($rsp),%r9
+	movq	8($rsp),%r8
+	movq	16($rsp),%rdi
+	movq	24($rsp),%rsi
+	movq	32($rsp),%rdx
+	movq	40($rsp),%rcx
+	movq	48($rsp),%rax
+	addq	$56,$rsp
+	ret
+
+	ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(_mcount))
+
+#undef mcount
+weak_alias(_mcount, mcount)