/* 64 bit S/390-specific implementation of profiling support.

   Copyright (C) 2001-2018 Free Software Foundation, Inc.

   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com)

   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, see

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

/* How profiling works on 64 bit S/390:

   On the start of each function _mcount is called with the address of a

   data word in %r1 (initialized to 0, used for counting). The compiler

   with the option -p generates code of the form:

           STM    6,15,24(15)

           BRAS   13,.LTN0_0

   .LT0_0:

   .LC13:  .long  .LP0

           .data

           .align 4

   .LP0:   .long  0

           .text

   # function profiler

           stg    14,4(15)

           lg     1,.LC13-.LT0_0(13)

           brasl  14,_mcount

           lg     14,4(15)

   The _mcount implementation now has to call __mcount_internal with the

   address of .LP0 as first parameter and the return address as second

   parameter. &.LP0 was loaded to %r1 and the return address is in %r14.

   _mcount may not modify any register.  */

	.globl C_SYMBOL_NAME(_mcount)

	.type C_SYMBOL_NAME(_mcount), @function

	cfi_startproc

	.align ALIGNARG(4)

C_LABEL(_mcount)

	/* Save the caller-clobbered registers.  */

        aghi  %r15,-224

	cfi_adjust_cfa_offset (224)

        stmg  %r14,%r5,160(%r15)

	cfi_offset (r14, 0)

	cfi_offset (r15, 8)

        lg    %r2,232(%r15)       # callers address  = first parameter

        la    %r2,0(%r2)          # clear bit 0

        la    %r3,0(%r14)         # callees address  = second parameter

#ifdef PIC

	brasl %r14,__mcount_internal@PLT

#else

	brasl %r14,__mcount_internal

#endif

	/* Pop the saved registers.  Please note that `mcount' has no

	   return value.  */

	lmg   %r14,%r5,160(%r15)

        aghi   %r15,224

	cfi_adjust_cfa_offset (-224)

        br    %r14

	cfi_endproc

	ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(_mcount))

#undef mcount

weak_alias (_mcount, mcount)