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###################################
#
# Copyright (C) 2009-2016 Free Software Foundation, Inc.
#
# Contributed by Michael Eager <eager@eagercon.com>.
#
# This file 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 3, or (at your option) any
# later version.
#
# 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.
#
# Under Section 7 of GPL version 3, you are granted additional
# permissions described in the GCC Runtime Library Exception, version
# 3.1, as published by the Free Software Foundation.
#
# You should have received a copy of the GNU General Public License and
# a copy of the GCC Runtime Library Exception along with this program;
# see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
# <http://www.gnu.org/licenses/>.
#
# modsi3.S
#
# modulo operation for 32 bit integers.
# Input : op1 in Reg r5
# op2 in Reg r6
# Output: op1 mod op2 in Reg r3
#
#######################################
.globl __modsi3
.ent __modsi3
.type __modsi3,@function
__modsi3:
.frame r1,0,r15
addik r1,r1,-16
swi r28,r1,0
swi r29,r1,4
swi r30,r1,8
swi r31,r1,12
BEQI r6,$LaDiv_By_Zero # Div_by_Zero # Division Error
BEQI r5,$LaResult_Is_Zero # Result is Zero
BGEId r5,$LaR5_Pos
ADD r28,r5,r0 # Get the sign of the result [ Depends only on the first arg]
RSUBI r5,r5,0 # Make r5 positive
$LaR5_Pos:
BGEI r6,$LaR6_Pos
RSUBI r6,r6,0 # Make r6 positive
$LaR6_Pos:
ADDIK r3,r0,0 # Clear mod
ADDIK r30,r0,0 # clear div
BLTId r5,$LaDIV2 # If r5 is still negative (0x80000000), skip
# the first bit search.
ADDIK r29,r0,32 # Initialize the loop count
# First part try to find the first '1' in the r5
$LaDIV1:
ADD r5,r5,r5 # left shift logical r5
BGEID r5,$LaDIV1 #
ADDIK r29,r29,-1
$LaDIV2:
ADD r5,r5,r5 # left shift logical r5 get the '1' into the Carry
ADDC r3,r3,r3 # Move that bit into the Mod register
rSUB r31,r6,r3 # Try to subtract (r30 a r6)
BLTi r31,$LaMOD_TOO_SMALL
OR r3,r0,r31 # Move the r31 to mod since the result was positive
ADDIK r30,r30,1
$LaMOD_TOO_SMALL:
ADDIK r29,r29,-1
BEQi r29,$LaLOOP_END
ADD r30,r30,r30 # Shift in the '1' into div
BRI $LaDIV2 # Div2
$LaLOOP_END:
BGEI r28,$LaRETURN_HERE
BRId $LaRETURN_HERE
rsubi r3,r3,0 # Negate the result
$LaDiv_By_Zero:
$LaResult_Is_Zero:
or r3,r0,r0 # set result to 0 [Both mod as well as div are 0]
$LaRETURN_HERE:
# Restore values of CSRs and that of r3 and the divisor and the dividend
lwi r28,r1,0
lwi r29,r1,4
lwi r30,r1,8
lwi r31,r1,12
rtsd r15,8
addik r1,r1,16
.end __modsi3
.size __modsi3, . - __modsi3
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