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/* Machine-specific calling sequence for `mcount' profiling function. alpha
Copyright (C) 1995-2022 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 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
<https://www.gnu.org/licenses/>. */
/* 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 a0..a5 as they may
contain function arguments. To work correctly with frame- less
functions, it is also necessary to preserve ra. Finally, division
routines are invoked with a special calling convention and the
compiler treats those calls as if they were instructions. In
particular, it doesn't save any of the temporary registers (caller
saved registers). It is therefore necessary to preserve all
caller-saved registers as well.
Upon entering _mcount, register $at holds the return address and ra
holds the return address of the function's caller (selfpc and frompc,
respectively in gmon.c language...). */
#include <sysdep.h>
.set noat
.set noreorder
LEAF(_mcount, 0xb0)
subq sp, 0xb0, sp
.prologue 0
stq a0, 0x00(sp)
mov ra, a0 # a0 = caller-pc
stq a1, 0x08(sp)
mov $at, a1 # a1 = self-pc
stq $at, 0x10(sp)
stq a2, 0x18(sp)
stq a3, 0x20(sp)
stq a4, 0x28(sp)
stq a5, 0x30(sp)
stq ra, 0x38(sp)
stq gp, 0x40(sp)
br gp, 1f
1: ldgp gp, 0(gp)
stq t0, 0x48(sp)
stq t1, 0x50(sp)
stq t2, 0x58(sp)
stq t3, 0x60(sp)
stq t4, 0x68(sp)
stq t5, 0x70(sp)
stq t6, 0x78(sp)
stq t7, 0x80(sp)
stq t8, 0x88(sp)
stq t9, 0x90(sp)
stq t10, 0x98(sp)
stq t11, 0xa0(sp)
stq v0, 0xa8(sp)
jsr ra, __mcount
ldq a0, 0x00(sp)
ldq a1, 0x08(sp)
ldq $at, 0x10(sp) # restore self-pc
ldq a2, 0x18(sp)
ldq a3, 0x20(sp)
ldq a4, 0x28(sp)
ldq a5, 0x30(sp)
ldq ra, 0x38(sp)
ldq gp, 0x40(sp)
mov $at, pv # make pv point to return address
ldq t0, 0x48(sp) # this is important under OSF/1 to
ldq t1, 0x50(sp) # ensure that the code that we return
ldq t2, 0x58(sp) # can correctly compute its gp
ldq t3, 0x60(sp)
ldq t4, 0x68(sp)
ldq t5, 0x70(sp)
ldq t6, 0x78(sp)
ldq t7, 0x80(sp)
ldq t8, 0x88(sp)
ldq t9, 0x90(sp)
ldq t10, 0x98(sp)
ldq t11, 0xa0(sp)
ldq v0, 0xa8(sp)
addq sp, 0xb0, sp
ret zero,($at),1
END(_mcount)
weak_alias (_mcount, mcount)
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