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/* Assembly functions for the Xtensa version of libgcc1.
Copyright (C) 2001, 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
Contributed by Bob Wilson (bwilson@tensilica.com) at Tensilica.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file into combinations with other programs,
and to distribute those combinations without any restriction coming
from the use of this file. (The General Public License restrictions
do apply in other respects; for example, they cover modification of
the file, and distribution when not linked into a combine
executable.)
GCC 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 General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#include "xtensa-config.h"
# Define macros for the ABS and ADDX* instructions to handle cases
# where they are not included in the Xtensa processor configuration.
.macro do_abs dst, src, tmp
#if XCHAL_HAVE_ABS
abs \dst, \src
#else
neg \tmp, \src
movgez \tmp, \src, \src
mov \dst, \tmp
#endif
.endm
.macro do_addx2 dst, as, at, tmp
#if XCHAL_HAVE_ADDX
addx2 \dst, \as, \at
#else
slli \tmp, \as, 1
add \dst, \tmp, \at
#endif
.endm
.macro do_addx4 dst, as, at, tmp
#if XCHAL_HAVE_ADDX
addx4 \dst, \as, \at
#else
slli \tmp, \as, 2
add \dst, \tmp, \at
#endif
.endm
.macro do_addx8 dst, as, at, tmp
#if XCHAL_HAVE_ADDX
addx8 \dst, \as, \at
#else
slli \tmp, \as, 3
add \dst, \tmp, \at
#endif
.endm
# Define macros for leaf function entry and return, supporting either the
# standard register windowed ABI or the non-windowed call0 ABI. These
# macros do not allocate any extra stack space, so they only work for
# leaf functions that do not need to spill anything to the stack.
.macro leaf_entry reg, size
#if XCHAL_HAVE_WINDOWED && !__XTENSA_CALL0_ABI__
entry \reg, \size
#else
/* do nothing */
#endif
.endm
.macro leaf_return
#if XCHAL_HAVE_WINDOWED && !__XTENSA_CALL0_ABI__
retw
#else
ret
#endif
.endm
#ifdef L_mulsi3
.align 4
.global __mulsi3
.type __mulsi3,@function
__mulsi3:
leaf_entry sp, 16
#if XCHAL_HAVE_MUL16
or a4, a2, a3
srai a4, a4, 16
bnez a4, .LMUL16
mul16u a2, a2, a3
leaf_return
.LMUL16:
srai a4, a2, 16
srai a5, a3, 16
mul16u a7, a4, a3
mul16u a6, a5, a2
mul16u a4, a2, a3
add a7, a7, a6
slli a7, a7, 16
add a2, a7, a4
#elif XCHAL_HAVE_MAC16
mul.aa.hl a2, a3
mula.aa.lh a2, a3
rsr a5, ACCLO
umul.aa.ll a2, a3
rsr a4, ACCLO
slli a5, a5, 16
add a2, a4, a5
#else /* !XCHAL_HAVE_MUL16 && !XCHAL_HAVE_MAC16 */
# Multiply one bit at a time, but unroll the loop 4x to better
# exploit the addx instructions and avoid overhead.
# Peel the first iteration to save a cycle on init.
# Avoid negative numbers.
xor a5, a2, a3 # top bit is 1 iff one of the inputs is negative
do_abs a3, a3, a6
do_abs a2, a2, a6
# Swap so the second argument is smaller.
sub a7, a2, a3
mov a4, a3
movgez a4, a2, a7 # a4 = max(a2, a3)
movltz a3, a2, a7 # a3 = min(a2, a3)
movi a2, 0
extui a6, a3, 0, 1
movnez a2, a4, a6
do_addx2 a7, a4, a2, a7
extui a6, a3, 1, 1
movnez a2, a7, a6
do_addx4 a7, a4, a2, a7
extui a6, a3, 2, 1
movnez a2, a7, a6
do_addx8 a7, a4, a2, a7
extui a6, a3, 3, 1
movnez a2, a7, a6
bgeui a3, 16, .Lmult_main_loop
neg a3, a2
movltz a2, a3, a5
leaf_return
.align 4
.Lmult_main_loop:
srli a3, a3, 4
slli a4, a4, 4
add a7, a4, a2
extui a6, a3, 0, 1
movnez a2, a7, a6
do_addx2 a7, a4, a2, a7
extui a6, a3, 1, 1
movnez a2, a7, a6
do_addx4 a7, a4, a2, a7
extui a6, a3, 2, 1
movnez a2, a7, a6
do_addx8 a7, a4, a2, a7
extui a6, a3, 3, 1
movnez a2, a7, a6
bgeui a3, 16, .Lmult_main_loop
neg a3, a2
movltz a2, a3, a5
#endif /* !XCHAL_HAVE_MUL16 && !XCHAL_HAVE_MAC16 */
leaf_return
.size __mulsi3,.-__mulsi3
#endif /* L_mulsi3 */
# Define a macro for the NSAU (unsigned normalize shift amount)
# instruction, which computes the number of leading zero bits,
# to handle cases where it is not included in the Xtensa processor
# configuration.
.macro do_nsau cnt, val, tmp, a
#if XCHAL_HAVE_NSA
nsau \cnt, \val
#else
mov \a, \val
movi \cnt, 0
extui \tmp, \a, 16, 16
bnez \tmp, 0f
movi \cnt, 16
slli \a, \a, 16
0:
extui \tmp, \a, 24, 8
bnez \tmp, 1f
addi \cnt, \cnt, 8
slli \a, \a, 8
1:
movi \tmp, __nsau_data
extui \a, \a, 24, 8
add \tmp, \tmp, \a
l8ui \tmp, \tmp, 0
add \cnt, \cnt, \tmp
#endif /* !XCHAL_HAVE_NSA */
.endm
#ifdef L_nsau
.section .rodata
.align 4
.global __nsau_data
.type __nsau_data,@object
__nsau_data:
#if !XCHAL_HAVE_NSA
.byte 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4
.byte 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3
.byte 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2
.byte 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2
.byte 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
.byte 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
.byte 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
.byte 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
.byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
.byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
.byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
.byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
.byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
.byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
.byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
.byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
#endif /* !XCHAL_HAVE_NSA */
.size __nsau_data,.-__nsau_data
.hidden __nsau_data
#endif /* L_nsau */
#ifdef L_udivsi3
.align 4
.global __udivsi3
.type __udivsi3,@function
__udivsi3:
leaf_entry sp, 16
bltui a3, 2, .Lle_one # check if the divisor <= 1
mov a6, a2 # keep dividend in a6
do_nsau a5, a6, a2, a7 # dividend_shift = nsau(dividend)
do_nsau a4, a3, a2, a7 # divisor_shift = nsau(divisor)
bgeu a5, a4, .Lspecial
sub a4, a4, a5 # count = divisor_shift - dividend_shift
ssl a4
sll a3, a3 # divisor <<= count
movi a2, 0 # quotient = 0
# test-subtract-and-shift loop; one quotient bit on each iteration
#if XCHAL_HAVE_LOOPS
loopnez a4, .Lloopend
#endif /* XCHAL_HAVE_LOOPS */
.Lloop:
bltu a6, a3, .Lzerobit
sub a6, a6, a3
addi a2, a2, 1
.Lzerobit:
slli a2, a2, 1
srli a3, a3, 1
#if !XCHAL_HAVE_LOOPS
addi a4, a4, -1
bnez a4, .Lloop
#endif /* !XCHAL_HAVE_LOOPS */
.Lloopend:
bltu a6, a3, .Lreturn
addi a2, a2, 1 # increment quotient if dividend >= divisor
.Lreturn:
leaf_return
.Lle_one:
beqz a3, .Lerror # if divisor == 1, return the dividend
leaf_return
.Lspecial:
# return dividend >= divisor
bltu a6, a3, .Lreturn0
movi a2, 1
leaf_return
.Lerror:
# just return 0; could throw an exception
.Lreturn0:
movi a2, 0
leaf_return
.size __udivsi3,.-__udivsi3
#endif /* L_udivsi3 */
#ifdef L_divsi3
.align 4
.global __divsi3
.type __divsi3,@function
__divsi3:
leaf_entry sp, 16
xor a7, a2, a3 # sign = dividend ^ divisor
do_abs a6, a2, a4 # udividend = abs(dividend)
do_abs a3, a3, a4 # udivisor = abs(divisor)
bltui a3, 2, .Lle_one # check if udivisor <= 1
do_nsau a5, a6, a2, a8 # udividend_shift = nsau(udividend)
do_nsau a4, a3, a2, a8 # udivisor_shift = nsau(udivisor)
bgeu a5, a4, .Lspecial
sub a4, a4, a5 # count = udivisor_shift - udividend_shift
ssl a4
sll a3, a3 # udivisor <<= count
movi a2, 0 # quotient = 0
# test-subtract-and-shift loop; one quotient bit on each iteration
#if XCHAL_HAVE_LOOPS
loopnez a4, .Lloopend
#endif /* XCHAL_HAVE_LOOPS */
.Lloop:
bltu a6, a3, .Lzerobit
sub a6, a6, a3
addi a2, a2, 1
.Lzerobit:
slli a2, a2, 1
srli a3, a3, 1
#if !XCHAL_HAVE_LOOPS
addi a4, a4, -1
bnez a4, .Lloop
#endif /* !XCHAL_HAVE_LOOPS */
.Lloopend:
bltu a6, a3, .Lreturn
addi a2, a2, 1 # increment quotient if udividend >= udivisor
.Lreturn:
neg a5, a2
movltz a2, a5, a7 # return (sign < 0) ? -quotient : quotient
leaf_return
.Lle_one:
beqz a3, .Lerror
neg a2, a6 # if udivisor == 1, then return...
movgez a2, a6, a7 # (sign < 0) ? -udividend : udividend
leaf_return
.Lspecial:
bltu a6, a3, .Lreturn0 # if dividend < divisor, return 0
movi a2, 1
movi a4, -1
movltz a2, a4, a7 # else return (sign < 0) ? -1 : 1
leaf_return
.Lerror:
# just return 0; could throw an exception
.Lreturn0:
movi a2, 0
leaf_return
.size __divsi3,.-__divsi3
#endif /* L_divsi3 */
#ifdef L_umodsi3
.align 4
.global __umodsi3
.type __umodsi3,@function
__umodsi3:
leaf_entry sp, 16
bltui a3, 2, .Lle_one # check if the divisor is <= 1
do_nsau a5, a2, a6, a7 # dividend_shift = nsau(dividend)
do_nsau a4, a3, a6, a7 # divisor_shift = nsau(divisor)
bgeu a5, a4, .Lspecial
sub a4, a4, a5 # count = divisor_shift - dividend_shift
ssl a4
sll a3, a3 # divisor <<= count
# test-subtract-and-shift loop
#if XCHAL_HAVE_LOOPS
loopnez a4, .Lloopend
#endif /* XCHAL_HAVE_LOOPS */
.Lloop:
bltu a2, a3, .Lzerobit
sub a2, a2, a3
.Lzerobit:
srli a3, a3, 1
#if !XCHAL_HAVE_LOOPS
addi a4, a4, -1
bnez a4, .Lloop
#endif /* !XCHAL_HAVE_LOOPS */
.Lloopend:
.Lspecial:
bltu a2, a3, .Lreturn
sub a2, a2, a3 # subtract once more if dividend >= divisor
.Lreturn:
leaf_return
.Lle_one:
# the divisor is either 0 or 1, so just return 0.
# someday we may want to throw an exception if the divisor is 0.
movi a2, 0
leaf_return
.size __umodsi3,.-__umodsi3
#endif /* L_umodsi3 */
#ifdef L_modsi3
.align 4
.global __modsi3
.type __modsi3,@function
__modsi3:
leaf_entry sp, 16
mov a7, a2 # save original (signed) dividend
do_abs a2, a2, a4 # udividend = abs(dividend)
do_abs a3, a3, a4 # udivisor = abs(divisor)
bltui a3, 2, .Lle_one # check if udivisor <= 1
do_nsau a5, a2, a6, a8 # udividend_shift = nsau(udividend)
do_nsau a4, a3, a6, a8 # udivisor_shift = nsau(udivisor)
bgeu a5, a4, .Lspecial
sub a4, a4, a5 # count = udivisor_shift - udividend_shift
ssl a4
sll a3, a3 # udivisor <<= count
# test-subtract-and-shift loop
#if XCHAL_HAVE_LOOPS
loopnez a4, .Lloopend
#endif /* XCHAL_HAVE_LOOPS */
.Lloop:
bltu a2, a3, .Lzerobit
sub a2, a2, a3
.Lzerobit:
srli a3, a3, 1
#if !XCHAL_HAVE_LOOPS
addi a4, a4, -1
bnez a4, .Lloop
#endif /* !XCHAL_HAVE_LOOPS */
.Lloopend:
.Lspecial:
bltu a2, a3, .Lreturn
sub a2, a2, a3 # subtract once more if udividend >= udivisor
.Lreturn:
bgez a7, .Lpositive
neg a2, a2 # if (dividend < 0), return -udividend
.Lpositive:
leaf_return
.Lle_one:
# udivisor is either 0 or 1, so just return 0.
# someday we may want to throw an exception if udivisor is 0.
movi a2, 0
leaf_return
.size __modsi3,.-__modsi3
#endif /* L_modsi3 */
#include "ieee754-df.S"
#include "ieee754-sf.S"
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