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###################################
#
# Copyright 2009, 2010 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/>.
#
# umodsi3.asm
#
# Unsigned modulo operation for 32 bit integers.
# Input : op1 in Reg r5
# op2 in Reg r6
# Output: op1 mod op2 in Reg r3
#
#######################################
.globl __umodsi3
.ent __umodsi3
.type __umodsi3,@function
__umodsi3:
.frame r1,0,r15
addik r1,r1,-12
swi r29,r1,0
swi r30,r1,4
swi r31,r1,8
BEQI r6,$LaDiv_By_Zero # Div_by_Zero # Division Error
BEQId r5,$LaResult_Is_Zero # Result is Zero
ADDIK r3,r0,0 # Clear div
ADDIK r30,r0,0 # clear mod
ADDIK r29,r0,32 # Initialize the loop count
# Check if r6 and r5 are equal # if yes, return 0
rsub r18,r5,r6
beqi r18,$LaRETURN_HERE
# Check if (uns)r6 is greater than (uns)r5. In that case, just return r5
xor r18,r5,r6
bgeid r18,16
addik r3,r5,0
blti r6,$LaRETURN_HERE
bri $LCheckr6
rsub r18,r5,r6 # MICROBLAZEcmp
bgti r18,$LaRETURN_HERE
# If r6 [bit 31] is set, then return result as r5-r6
$LCheckr6:
bgtid r6,$LaDIV0
addik r3,r0,0
addik r18,r0,0x7fffffff
and r5,r5,r18
and r6,r6,r18
brid $LaRETURN_HERE
rsub r3,r6,r5
# First part: try to find the first '1' in the r5
$LaDIV0:
BLTI r5,$LaDIV2
$LaDIV1:
ADD r5,r5,r5 # left shift logical r5
BGEID r5,$LaDIV1 #
ADDIK r29,r29,-1
$LaDIV2:
ADD r5,r5,r5 # left shift logical r5 get the '1' into the Carry
ADDC r3,r3,r3 # Move that bit into the Mod register
rSUB r31,r6,r3 # Try to subtract (r3 a r6)
BLTi r31,$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:
BRI $LaRETURN_HERE
$LaDiv_By_Zero:
$LaResult_Is_Zero:
or r3,r0,r0 # set result to 0
$LaRETURN_HERE:
# Restore values of CSRs and that of r3 and the divisor and the dividend
lwi r29,r1,0
lwi r30,r1,4
lwi r31,r1,8
rtsd r15,8
addik r1,r1,12
.end __umodsi3
.size __umodsi3, . - __umodsi3
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