1 ; $NetBSD: milli_tiny.S,v 1.1 2014/02/24 07:23:43 skrll Exp $ 2 3 ; Copyright (c) 2003 ITOH Yasufumi. 4 ; All rights reserved. 5 ; 6 ; Redistribution and use in source and binary forms, with or without 7 ; modification, are permitted provided that the following conditions 8 ; are met: 9 ; 1. Redistributions of source code must retain the above copyright 10 ; notice, this list of conditions and the following disclaimer. 11 ; 2. Redistributions in binary forms are unlimited. 12 ; 13 ; THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' 14 ; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 ; THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 ; PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS 17 ; BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 ; CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 ; SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 ; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 ; CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 ; ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 ; THE POSSIBILITY OF SUCH DAMAGE. 24 25 ; millicode library, optimized for size 26 27 .level 1.0 28 .code 29 .align 4 30 31 ; $$divU unsigned division, return quotient 32 ; 33 ; inputs: 34 ; %r26 dividend 35 ; %r25 divisor 36 ; %r31 return address 37 ; outputs: 38 ; %r29 quotient 39 ; %r1, %r25, %r26 undefined 40 .export $$divU,millicode 41 $$divU: 42 .proc 43 .callinfo millicode,no_unwind 44 .entry 45 comb,<,n %r25,0,bigdivisor_divU ; special case (>=0x80000000) 46 bl sub_divU,%r29 47 subt,= %r0,%r25,%r1 ; trap divide by 0, negate 48 49 bv %r0(%r31) ; return millicode 50 .exit 51 addc %r26,%r26,%r29 ; fix quotient 52 bigdivisor_divU: 53 comclr,<< %r26,%r25,%r29 ; if dividend >= divisor 54 ldi 1,%r29 ; quotient is 1 55 bv,n %r0(%r31) ; return millicode 56 .procend 57 58 ; Note this is not a normal subroutine 59 ; r29: return address 60 sub_divU: 61 stwm %r19,64(%sp) 62 ldi 31,%r19 63 64 ds %r0,%r1,%r0 65 addc %r26,%r26,%r26 66 ds %r0,%r25,%r1 67 loop_sub_divU: ; addc/ds 31 times 68 addc %r26,%r26,%r26 69 addib,<> -1,%r19,loop_sub_divU 70 ds %r1,%r25,%r1 71 72 bv %r0(%r29) 73 ldwm -64(%sp),%r19 74 75 ; $$remU unsigned division, return remainder 76 ; 77 ; inputs: 78 ; %r26 dividend 79 ; %r25 divisor 80 ; %r31 return address 81 ; outputs: 82 ; %r29 remainder 83 ; %r1, %r25, %r26 undefined 84 .export $$remU,millicode 85 $$remU: 86 .proc 87 .callinfo millicode,no_unwind 88 .entry 89 comb,<,n %r25,0,bigdivisor_remU ; special case (>=0x80000000) 90 bl sub_divU,%r29 91 subt,= %r0,%r25,%r1 ; trap divide by 0, negate 92 93 comclr,>= %r1,%r0,%r0 94 addl %r1,%r25,%r1 ; fix remainder 95 bv %r0(%r31) ; return millicode 96 .exit 97 copy %r1,%r29 ; the return value is remainder 98 bigdivisor_remU: 99 sub,>>= %r26,%r25,%r29 ; if dividend < divisor 100 copy %r26,%r29 ; the remainder is dividend 101 bv,n %r0(%r31) ; return millicode 102 .procend 103 104 ; $$mulU unsigned multiplication 105 ; 106 ; inputs: 107 ; %r26 multiplicand 108 ; %r25 multiplier 109 ; %r31 return address 110 ; outputs: 111 ; %r29 product 112 ; %r1, %r25, %r26 undefined 113 .export $$mulU,millicode 114 .export $$mulI,millicode 115 $$mulU: 116 $$mulI: ; XXX actually wrong (not signed) but works for small positive numbers 117 .proc 118 .callinfo frame=0,no_calls,millicode 119 .entry 120 copy %r0,%r29 121 ldi 32,%r1 ; loop counter 122 123 add,nuv %r25,%r25,%r25 ; shift left, skip next if not C 124 loop_mul: 125 sh1add,tr %r29,%r26,%r29 ; shift left and add, skip next 126 sh1add %r29,%r0,%r29 ; shift left only 127 addib,<>,n -1,%r1,loop_mul ; check loop condition 128 add,nuv %r25,%r25,%r25 ; shift left, skip next if not C 129 .exit 130 bv,n %r0(%r31) ; return millicode 131 .procend 132
Indexes created Wed Sep 24 15:09:51 GMT 2025