Make profiling actually work. The gcc compiler emits a call to the

_mcount() stub when profiling is enabled. Emit this code sequence
for assembly routines as welli (MCOUNT definition in <machine/asm.h>.
We do not pass the GOT entry however as the 4th argument, because it's
not used. The _mcount() stub calls __mcount(), which does the actual
work. Define _MCOUNT_DECL to define __mcount. We do not have an
implementation of mcount(), so we define MCOUNT as empty, but have a
weak alias to _mcount() in _mcount.S.
Note that the _mcount() stub in the kernel is slightly different from
the stub in userland. This is because we do not have to worry about
nested routines in the kernel.

2 files changed, 79 insertions, 4 deletions

diff --git a/lib/libc/ia64/gen/Makefile.inc b/lib/libc/ia64/gen/Makefile.inc
index 1eb7264..5358ea8 100644
--- a/lib/libc/ia64/gen/Makefile.inc
+++ b/lib/libc/ia64/gen/Makefile.inc
@@ -1,10 +1,10 @@
 # $FreeBSD$
 
 SRCS+=	__divdf3.S __divdi3.S __divsf3.S __divsi3.S __moddi3.S __modsi3.S \
-	__udivdi3.S __udivsi3.S __umoddi3.S __umodsi3.S _setjmp.S fabs.S \
-	_set_tp.c flt_rounds.c fpgetmask.c fpgetround.c fpsetmask.c \
-	fpsetround.c infinity.c \
-	ldexp.c makecontext.c modf.c setjmp.S signalcontext.c sigsetjmp.S
+	__udivdi3.S __udivsi3.S __umoddi3.S __umodsi3.S _mcount.S _set_tp.c \
+	_setjmp.S fabs.S flt_rounds.c fpgetmask.c fpgetround.c fpsetmask.c \
+	fpsetround.c infinity.c ldexp.c makecontext.c modf.c setjmp.S \
+	signalcontext.c sigsetjmp.S
 
 # The following may go away if function _Unwind_FindTableEntry()
 # will be part of GCC.
diff --git a/lib/libc/ia64/gen/_mcount.S b/lib/libc/ia64/gen/_mcount.S
new file mode 100644
index 0000000..d9e9b76
--- /dev/null
+++ b/lib/libc/ia64/gen/_mcount.S
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2004 Marcel Moolenaar
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <machine/asm.h>
+__FBSDID("$FreeBSD$");
+
+	.text
+
+/*
+ * Important registers:
+ *	r8	structure return address
+ *	r15	static link (nested routines)
+ *	rp	our return address
+ *	in0	caller's ar.pfs
+ *	in1	caller's gp
+ *	in2	caller's rp
+ *	in3	GOT entry
+ *	ar.pfs	our pfs
+ */
+ENTRY_NOPROFILE(_mcount, 4)
+	alloc		loc0 = ar.pfs, 4, 4, 2, 0
+	mov		loc1 = r8
+	mov		loc2 = rp
+	mov		loc3 = r15
+	;;
+	mov		out0 = in2
+	mov		out1 = rp
+	br.call.sptk	rp = __mcount
+	;;
+1:
+	mov		gp = in1
+	mov		r14 = ip
+	mov		b7 = loc2
+	;;
+	add		r14 = 2f - 1b, r14
+	mov		ar.pfs = loc0
+	mov		rp = in2
+	;;
+	mov		r15 = loc3
+	mov		b7 = r14
+	mov		b6 = loc2
+	mov		r8 = loc1
+	mov		r14 = in0
+	br.ret.sptk	b7
+	;;
+2:
+	mov		ar.pfs = r14
+	br.sptk		b6
+	;;
+END(_mcount)
+
+WEAK_ALIAS(mcount, _mcount)