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+/* PowerPC-specific implementation of profiling support.
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ 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 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. */
+
+/* This would be bad. */
+#ifdef PROF
+#undef PROF
+#endif
+
+#include <sysdep.h>
+
+/* We do profiling as described in the SYSV ELF ABI, _mcount is called
+ with the address of a data word in r0 (that is different for every
+ routine, initialised to 0, and otherwise unused). The caller has put
+ the address the caller will return to in the usual place on the stack,
+ 4(%r1). _mcount is responsible for ensuring that when it returns no
+ argument-passing registers are disturbed, and that the LR is set back
+ to (what the caller sees as) 4(%r1).
+
+ This is intended so that the following code can be inserted at the
+ front of any routine without changing the routine:
+
+ .data
+ .align 2
+ 0: .long 0
+ .previous
+ mflr %r0
+ lis %r11,0b@ha
+ stw %r0,4(%r1)
+ addi %r0,%r11,0b@l
+ bl _mcount
+*/
+
+ENTRY(_mcount)
+ stwu %r1,-48(%r1)
+/* We need to save the parameter-passing registers. */
+ stw %r3, 12(%r1)
+ stw %r4, 16(%r1)
+ stw %r5, 20(%r1)
+ stw %r6, 24(%r1)
+ mflr %r4
+ lwz %r3, 52(%r1)
+ mfcr %r5
+ stw %r7, 28(%r1)
+ stw %r8, 32(%r1)
+ stw %r9, 36(%r1)
+ stw %r10,40(%r1)
+ stw %r4, 44(%r1)
+ stw %r5, 8(%r1)
+ bl JUMPTARGET(__mcount_internal)
+ /* Restore the registers... */
+ lwz %r6, 8(%r1)
+ lwz %r0, 44(%r1)
+ lwz %r3, 12(%r1)
+ mtctr %r0
+ lwz %r4, 16(%r1)
+ mtcrf 0xff,%r6
+ lwz %r5, 20(%r1)
+ lwz %r6, 24(%r1)
+ lwz %r0, 52(%r1)
+ lwz %r7, 28(%r1)
+ lwz %r8, 32(%r1)
+ mtlr %r0
+ lwz %r9, 36(%r1)
+ lwz %r10,40(%r1)
+ /* ...unwind the stack frame, and return to your usual programming. */
+ addi %r1,%r1,48
+ bctr
+END(_mcount)