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1.1 ! root 1: ! 2: # bignum add routine ! 3: # basic data representation is each bigit is a positive number ! 4: # less than 2^30, except for the leading bigit, which is in ! 5: # the range -2^30 < x < 2^30. ! 6: ! 7: .globl _adbig ! 8: .globl Bexport ! 9: .globl backfr ! 10: # ! 11: # Initialization section ! 12: # ! 13: _adbig: .word 0x0fc0 #save registers 6-11 ! 14: movl 4(ap),r1 #arg1 = addr of 1st bignum ! 15: movl 8(ap),r2 #arg2 = addr of 2nd bignum ! 16: clrl r5 #r5 = carry ! 17: movl $0xC0000000,r4 #r4 = clear constant. ! 18: movl sp,r10 #save start address of bignum on stack. ! 19: #note well that this is 4 above the actual ! 20: #low order word. ! 21: # ! 22: # first loop is to waltz through both bignums adding ! 23: # bigits, pushing them onto stack. ! 24: # ! 25: loop1: addl3 (r1),(r2),r0 #add bigits ! 26: addl2 r5,r0 #add carry ! 27: bicl3 r4,r0,-(sp) #save sum, no overflow possible ! 28: extv $30,$2,r0,r5 #sign extend two high order bits ! 29: #to be next carry. ! 30: movl 4(r1),r1 #get cdr ! 31: bleq out1 #negative indicates end of list. ! 32: movl 4(r2),r2 #get cdr of second bignum ! 33: bgtr loop1 #if neither list at end, do it again ! 34: # ! 35: # second loop propagates carries through higher order words. ! 36: # It assumes remaining list in r1. ! 37: # ! 38: loop2: addl3 (r1),r5,r0 #add bigits and carry ! 39: bicl3 r4,r0,-(sp) #save sum, no overflow possible ! 40: extv $30,$2,r0,r5 #sign extend two high order bits ! 41: #to be next carry. ! 42: movl 4(r1),r1 #get cdr ! 43: out2: bgtr loop2 #negative indicates end of list. ! 44: out2a: pushl r5 ! 45: # ! 46: # suppress unnecessary leading zeroes and -1's ! 47: # ! 48: iexport:movl sp,r11 #more set up for output routine ! 49: ckloop: ! 50: Bexport:tstl (r11) #look at leading bigit ! 51: bgtr copyit #if positive, can allocate storage etc. ! 52: blss negchk #if neg, still a chance we can get by ! 53: cmpl r11,r10 #check to see that ! 54: bgeq copyit #we don't pop everything off of stack ! 55: tstl (r11)+ #incr r11 ! 56: brb ckloop #examine next ! 57: negchk: ! 58: mcoml (r11),r3 #r3 is junk register ! 59: bneq copyit #short test for -1 ! 60: tstl 4(r11) #examine next bigit ! 61: beql copyit #if zero must must leave as is. ! 62: cmpl r11,r10 #check to see that ! 63: bgeq copyit #we don't pop everything off of stack ! 64: tstl (r11)+ #incr r11 ! 65: bisl2 r4,(r11) #set high order two bits ! 66: brb negchk #try to supress more leading -1's ! 67: # ! 68: # The following code is an error exit from the first loop ! 69: # and is out of place to avoid a jump around a jump. ! 70: # ! 71: out1: movl 4(r2),r1 #get next addr of list to continue. ! 72: brb out2 #if second list simult. exhausted, do ! 73: #right thing. ! 74: # ! 75: # loop3 is a faster version of loop2 when carries are no ! 76: # longer necessary. ! 77: # ! 78: loop3a: pushl (r1) #get datum ! 79: loop3: movl 4(r1),r1 #get cdr ! 80: bgtr loop3a #if not at end get next cell ! 81: brb out2a ! 82: ! 83: # ! 84: # create linked list representation of bignum ! 85: # ! 86: copyit: subl3 r11,r10,r2 #see if we can get away with allocating an int ! 87: bneq on1 #test for having popped everything ! 88: subl3 $4,r10,r11 #if so, fix up pointer to bottom ! 89: brb intout #and allocate int. ! 90: on1: cmpl r2,$4 #if = 4, then can do ! 91: beql intout ! 92: calls $0,_newsdot #get new cell for new bignum ! 93: backfr: movl r0,(r6)+ #push address of cell on ! 94: #arg stack to save from garbage collection. ! 95: #There is guaranteed to be slop for a least one ! 96: #push without checking. ! 97: movl r0,r8 #r8 = result of adbig ! 98: loop4: movl -(r10),(r0) #save bigit ! 99: movl r0,r9 #r9 = old cell, to link ! 100: cmpl r10,r11 #have we copy'ed all the bigits? ! 101: bleq done ! 102: calls $0,_newsdot #get new cell for new bignum ! 103: movl r0,4(r9) #link new cell to old ! 104: brb loop4 ! 105: done: ! 106: clrl 4(r9) #indicate end of list with 0 ! 107: movl -(r6),r0 #give resultant address. ! 108: ret ! 109: # ! 110: # export integer ! 111: # ! 112: intout: pushl (r11) ! 113: calls $1,_inewint ! 114: ret ! 115: .globl _mulbig ! 116: # ! 117: # bignum multiplication routine ! 118: # ! 119: # Initialization section ! 120: # ! 121: _mulbig:.word 0x0fc0 #save regs 6-11 ! 122: movl 4(ap),r1 #get address of first bignum ! 123: movl sp,r11 #save top of 1st bignum ! 124: mloop1: pushl (r1) #get bigit ! 125: movl 4(r1),r1 #get cdr ! 126: bgtr mloop1 #repeat if not done ! 127: movl sp,r10 #save bottom of 1st bignum, top of 2nd bignum ! 128: ! 129: movl 8(ap),r1 #get address of 2nd bignum ! 130: mloop2: pushl (r1) #get bigit ! 131: movl 4(r1),r1 #get cdr ! 132: bgtr mloop2 #repeat if not done ! 133: movl sp,r9 #save bottom of 2nd bignum ! 134: subl3 r9,r11,r6 #r6 contains sum of lengths of bignums ! 135: subl2 r6,sp ! 136: movl sp,r8 #save bottom of product bignum ! 137: # ! 138: # Actual multiplication ! 139: # ! 140: m1: movc5 $0,(r8),$0,r6,(r8)#zap out stack space ! 141: movl r9,r7 #r7 = &w[j +n] (+4 for a.d.) through calculation ! 142: subl3 $4,r10,r4 #r4 = &v[j] ! 143: ! 144: m3: movl r7,r5 #r7 = &w[j+n] ! 145: subl3 $4,r11,r3 #r3 = &u[i] ! 146: clrl r2 #clear carry. ! 147: ! 148: m4: addl2 -(r5),r2 #add w[i + j] to carry (no ofl poss) ! 149: emul (r3),(r4),r2,r0 #r0 = u[i] * v[j] + sext(carry) ! 150: extzv $0,$30,r0,(r5) #get new bigit ! 151: extv $30,$32,r0,r2 #get new carry ! 152: ! 153: m5: acbl r10,$-4,r3,m4 #r3 =- 4; if(r3 >= r10) goto m4; r10 = &[u1]; ! 154: movl r2,-(r5) #save w[j] = carry ! 155: ! 156: m6: subl2 $4,r7 #add just &w[j+n] (+4 for autodec) ! 157: acbl r9,$-4,r4,m3 #r4 =- 4; if(r4>=r9) goto m5; r9 = &v[1] ! 158: ! 159: movl r9,r10 #set up for output routine ! 160: movl $0xC0000000,r4 #r4 = clear constant. ! 161: movq 20(fp),r6 #restor _np and _lbot ! ! 162: brw iexport #do it!
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