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glibc/ports/sysdeps/alpha/div_libc.h
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/* Copyright (C) 2004-2013 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 | |
<http://www.gnu.org/licenses/>. */ | |
/* Common bits for implementing software divide. */ | |
#include <sysdep.h> | |
#ifdef __linux__ | |
# include <asm/gentrap.h> | |
# include <asm/pal.h> | |
#else | |
# include <machine/pal.h> | |
#endif | |
/* These are not normal C functions. Argument registers are t10 and t11; | |
the result goes in t12; the return address is in t9. Only t12 and AT | |
may be clobbered. */ | |
#define X t10 | |
#define Y t11 | |
#define RV t12 | |
#define RA t9 | |
/* The secureplt format does not allow the division routines to be called | |
via plt; there aren't enough registers free to be clobbered. Avoid | |
setting the symbol type to STT_FUNC, so that the linker won't be tempted | |
to create a plt entry. */ | |
#define funcnoplt notype | |
/* None of these functions should use implicit anything. */ | |
.set nomacro | |
.set noat | |
/* Code fragment to invoke _mcount for profiling. This should be invoked | |
directly after allocation of the stack frame. */ | |
.macro CALL_MCOUNT | |
#ifdef PROF | |
stq ra, 0(sp) | |
stq pv, 8(sp) | |
stq gp, 16(sp) | |
cfi_rel_offset (ra, 0) | |
cfi_rel_offset (pv, 8) | |
cfi_rel_offset (gp, 16) | |
br AT, 1f | |
.set macro | |
1: ldgp gp, 0(AT) | |
mov RA, ra | |
lda AT, _mcount | |
jsr AT, (AT), _mcount | |
.set nomacro | |
ldq ra, 0(sp) | |
ldq pv, 8(sp) | |
ldq gp, 16(sp) | |
cfi_restore (ra) | |
cfi_restore (pv) | |
cfi_restore (gp) | |
/* Realign subsequent code with what we'd have without this | |
macro at all. This means aligned with one arithmetic insn | |
used within the bundle. */ | |
.align 4 | |
nop | |
#endif | |
.endm | |
/* In order to make the below work, all top-level divide routines must | |
use the same frame size. */ | |
#define FRAME 64 | |
/* Code fragment to generate an integer divide-by-zero fault. When | |
building libc.so, we arrange for there to be one copy of this code | |
placed late in the dso, such that all branches are forward. When | |
building libc.a, we use multiple copies to avoid having an out of | |
range branch. Users should jump to DIVBYZERO. */ | |
.macro DO_DIVBYZERO | |
#ifdef PIC | |
#define DIVBYZERO __divbyzero | |
.section .gnu.linkonce.t.divbyzero, "ax", @progbits | |
.globl __divbyzero | |
.type __divbyzero, @function | |
.usepv __divbyzero, no | |
.hidden __divbyzero | |
#else | |
#define DIVBYZERO $divbyzero | |
#endif | |
.align 4 | |
DIVBYZERO: | |
cfi_startproc | |
cfi_return_column (RA) | |
cfi_def_cfa_offset (FRAME) | |
mov a0, RV | |
unop | |
lda a0, GEN_INTDIV | |
call_pal PAL_gentrap | |
mov RV, a0 | |
clr RV | |
lda sp, FRAME(sp) | |
cfi_def_cfa_offset (0) | |
ret $31, (RA), 1 | |
cfi_endproc | |
.size DIVBYZERO, .-DIVBYZERO | |
.endm | |
/* Like the ev6 instructions, but fall back to stack use on prior machines. */ | |
.arch ev6 | |
.macro _ITOFS gr, fr, slot | |
#ifdef __alpha_fix__ | |
itofs \gr, \fr | |
#else | |
stl \gr, \slot(sp) | |
lds \fr, \slot(sp) | |
#endif | |
.endm | |
.macro _ITOFT gr, fr, slot | |
#ifdef __alpha_fix__ | |
itoft \gr, \fr | |
#else | |
stq \gr, \slot(sp) | |
ldt \fr, \slot(sp) | |
#endif | |
.endm | |
.macro _FTOIT fr, gr, slot | |
#ifdef __alpha_fix__ | |
ftoit \fr, \gr | |
#else | |
stt \fr, \slot(sp) | |
ldq \gr, \slot(sp) | |
#endif | |
.endm | |
/* Similarly, but move two registers. Schedules better for pre-ev6. */ | |
.macro _ITOFT2 gr1, fr1, slot1, gr2, fr2, slot2 | |
#ifdef __alpha_fix__ | |
itoft \gr1, \fr1 | |
itoft \gr2, \fr2 | |
#else | |
stq \gr1, \slot1(sp) | |
stq \gr2, \slot2(sp) | |
ldt \fr1, \slot1(sp) | |
ldt \fr2, \slot2(sp) | |
#endif | |
.endm |