movl #1,r0 ; return SS$_NORMAL
ret
\f
- .title (generated)
-
- .psect code,nowrt
-
-.entry BN_DIV_WORDS,^m<r2,r3,r4,r5,r6,r7,r8,r9,r10>
- subl2 #4,sp
-
- clrl r9
- movl #2,r8
-
- tstl 12(ap)
- bneq noname.2
- mnegl #1,r10
- brw noname.3
- tstl r0
- nop
-noname.2:
-
- pushl 12(ap)
- calls #1,BN_NUM_BITS_WORD
- movl r0,r7
-
- cmpl r7,#32
- beql noname.4
- ashl r7,#1,r2
- cmpl 4(ap),r2
- blequ noname.4
-
- pushl r7
- calls #1,BN_DIV_WORDS_ABORT
-noname.4:
-
- subl3 r7,#32,r7
-
- movl 12(ap),r2
- cmpl 4(ap),r2
- blssu noname.5
- subl2 r2,4(ap)
-noname.5:
-
- tstl r7
- beql noname.6
-
- ashl r7,r2,12(ap)
-
- ashl r7,4(ap),r4
- subl3 r7,#32,r3
- subl3 r3,#32,r2
- extzv r3,r2,8(ap),r2
- bisl3 r4,r2,4(ap)
-
- ashl r7,8(ap),8(ap)
-noname.6:
-
- bicl3 #65535,12(ap),r2
- extzv #16,#16,r2,r5
-
- bicl3 #-65536,12(ap),r6
-
-noname.7:
-
- moval 4(ap),r2
- movzwl 2(r2),r0
- cmpl r0,r5
- bneq noname.8
-
- movzwl #65535,r4
- brb noname.9
-noname.8:
-
- clrl r1
- movl (r2),r0
- movl r5,r2
- bgeq vcg.1
- cmpl r2,r0
- bgtru vcg.2
- incl r1
- brb vcg.2
- nop
-vcg.1:
- ediv r2,r0,r1,r0
-vcg.2:
- movl r1,r4
-noname.9:
-
-noname.10:
-
- mull3 r5,r4,r0
- subl3 r0,4(ap),r3
-
- bicl3 #65535,r3,r0
- bneq noname.13
- mull3 r6,r4,r2
- ashl #16,r3,r1
- bicl3 #65535,8(ap),r0
- extzv #16,#16,r0,r0
- addl2 r0,r1
- cmpl r2,r1
- bgtru noname.12
-noname.11:
-
- brb noname.13
- nop
-noname.12:
-
- decl r4
- brb noname.10
-noname.13:
-
- mull3 r5,r4,r1
-
- mull3 r6,r4,r0
-
- extzv #16,#16,r0,r3
-
- ashl #16,r0,r2
- bicl3 #65535,r2,r0
-
- addl2 r3,r1
-
- moval 8(ap),r3
- cmpl (r3),r0
- bgequ noname.15
- incl r1
-noname.15:
-
- subl2 r0,(r3)
-
- cmpl 4(ap),r1
- bgequ noname.16
-
- addl2 12(ap),4(ap)
-
- decl r4
-noname.16:
-
- subl2 r1,4(ap)
-
- decl r8
- beql noname.18
-noname.17:
-
- ashl #16,r4,r9
-
- ashl #16,4(ap),r2
- movzwl 2(r3),r0
- bisl2 r0,r2
- bicl3 #0,r2,4(ap)
-
- bicl3 #-65536,(r3),r0
- ashl #16,r0,(r3)
- brw noname.7
- nop
-noname.18:
+ .title vax_bn_div_words unsigned divide
+;
+; Richard Levitte 20-Nov-2000
+;
+; ULONG bn_div_words(ULONG h, ULONG l, ULONG d)
+; {
+; return ((ULONG)((((ULLONG)h)<<32)|l) / (ULLONG)d);
+; }
+;
+; Using EDIV would be very easy, if it didn't do signed calculations.
+; Therefore, som extra things have to happen around it. The way to
+; handle that is to shift all operands right one step (basically dividing
+; them by 2) and handle the different cases depending on what the lowest
+; bit of each operand was.
+;
+; To start with, let's define the following:
+;
+; a' = l & 1
+; a2 = <h,l> >> 1 # UNSIGNED shift!
+; b' = d & 1
+; b2 = d >> 1 # UNSIGNED shift!
+;
+; Now, use EDIV to calculate a quotient and a remainder:
+;
+; q'' = a2/b2
+; r'' = a2 - q''*b2
+;
+; If b' is 0, the quotient is already correct, we just need to adjust the
+; remainder:
+;
+; if (b' == 0)
+; {
+; r = 2*r'' + a'
+; q = q''
+; }
+;
+; If b' is 1, we need to do other adjustements. The first thought is the
+; following (note that r' will not always have the right value, but an
+; adjustement follows further down):
+;
+; if (b' == 1)
+; {
+; q' = q''
+; r' = a - q'*b
+;
+; However, one can note the folowing relationship:
+;
+; r'' = a2 - q''*b2
+; => 2*r'' = 2*a2 - 2*q''*b2
+; = { a = 2*a2 + a', b = 2*b2 + b' = 2*b2 + 1,
+; q' = q'' }
+; = a - a' - q'*(b - 1)
+; = a - q'*b - a' + q'
+; = r' - a' + q'
+; => r' = 2*r'' - q' + a'
+;
+; This enables us to use r'' instead of discarding and calculating another
+; modulo:
+;
+; if (b' == 1)
+; {
+; q' = q''
+; r' = (r'' << 1) - q' + a'
+;
+; Now, all we have to do is adjust r', because it might be < 0:
+;
+; while (r' < 0)
+; {
+; r' = r' + b
+; q' = q' - 1
+; }
+; }
+;
+; return q'
- bisl2 r4,r9
+h=4 ;(AP) h by value (input)
+l=8 ;(AP) l by value (input)
+d=12 ;(AP) d by value (input)
- movl r9,r10
+aprim=r5
+a2=r6
+a20=r6
+a21=r7
+bprim=r8
+b2=r9
+qprim=r10 ; initially used as q''
+rprim=r11 ; initially used as r''
-noname.3:
- movl r10,r0
- ret
- tstl r0
-\f
.psect code,nowrt
-.entry BN_ADD_WORDS,^m<r2,r3,r4,r5,r6,r7>
-
- tstl 16(ap)
- bgtr noname.21
- clrl r7
- brw noname.22
-noname.21:
-
- clrl r4
-
- tstl r0
-noname.23:
-
- movl 8(ap),r6
- addl3 r4,(r6),r2
-
- bicl2 #0,r2
-
- clrl r0
- cmpl r2,r4
- bgequ vcg.3
- incl r0
-vcg.3:
- movl r0,r4
-
- movl 12(ap),r5
- addl3 (r5),r2,r1
- bicl2 #0,r1
-
- clrl r0
- cmpl r1,r2
- bgequ vcg.4
- incl r0
-vcg.4:
- addl2 r0,r4
-
- movl 4(ap),r3
- movl r1,(r3)
-
- decl 16(ap)
- bgtr gen.1
- brw noname.25
-gen.1:
-noname.24:
-
- addl3 r4,4(r6),r2
-
- bicl2 #0,r2
-
- clrl r0
- cmpl r2,r4
- bgequ vcg.5
- incl r0
-vcg.5:
- movl r0,r4
-
- addl3 4(r5),r2,r1
- bicl2 #0,r1
-
- clrl r0
- cmpl r1,r2
- bgequ vcg.6
- incl r0
-vcg.6:
- addl2 r0,r4
-
- movl r1,4(r3)
-
- decl 16(ap)
- bleq noname.25
-noname.26:
-
- addl3 r4,8(r6),r2
-
- bicl2 #0,r2
-
- clrl r0
- cmpl r2,r4
- bgequ vcg.7
- incl r0
-vcg.7:
- movl r0,r4
-
- addl3 8(r5),r2,r1
- bicl2 #0,r1
-
- clrl r0
- cmpl r1,r2
- bgequ vcg.8
- incl r0
-vcg.8:
- addl2 r0,r4
-
- movl r1,8(r3)
-
- decl 16(ap)
- bleq noname.25
-noname.27:
-
- addl3 r4,12(r6),r2
-
- bicl2 #0,r2
-
- clrl r0
- cmpl r2,r4
- bgequ vcg.9
- incl r0
-vcg.9:
- movl r0,r4
-
- addl3 12(r5),r2,r1
- bicl2 #0,r1
-
- clrl r0
- cmpl r1,r2
- bgequ vcg.10
- incl r0
-vcg.10:
- addl2 r0,r4
+.entry bn_div_words,^m<r2,r3,r4,r5,r6,r7,r8,r9,r10,r11>
+ movl l(ap),r2
+ movl h(ap),r3
+ movl d(ap),r4
+
+ movl #0,aprim
+ movl #0,bprim
+ movl #0,r0
+
+ rotl #-1,r2,a20 ; a20 = l >> 1 (almost)
+ rotl #-1,r3,a21 ; a21 = h >> 1 (almost)
+ rotl #-1,r4,b2 ; b2 = d >> 1 (almost)
+
+ tstl a20
+ bgeq 1$
+ xorl2 #^X80000000,a20 ; fixup a20 so highest bit is 0
+ incl aprim ; a' = 1
+1$:
+ tstl a21
+ bgeq 2$
+ xorl2 #^X80000000,a20 ; fixup a20 so highest bit is 1,
+ ; since that's what was lowest in a21
+ xorl2 #^X80000000,a21 ; fixup a21 so highest bit is 1
+2$:
+ tstl b2
+ bgeq 666$ ; Uh-oh, the divisor is 0...
+ bgrt 3$
+ xorl2 #^X80000000,b2 ; fixup b2 so highest bit is 1
+ incl bprim
+3$:
+ tstl b2
+ bneq 4$ ; if b2 is 0, we know that bprim is 1
+ tstl a21
+ bneq 666$ ; if higher half isn't 0, we overflow
+ movl r0,a20 ; otherwise, we have our result
+ brb 42$
+4$:
+ ediv b2,a2,qprim,rprim
+
+ tstl bprim
+ bneq 5$ ; If b' != 0, go to the other part
+; addl3 rprim,rprim,r1
+; addl2 aprim,r1
+ brb 42$
+5$:
+ ash #1,rprim,rprim
+ subl2 qprim,rprim
+ addl2 aprim,rprim
+ bgeq 7$
+6$:
+ decl qprim
+ addl2 r4,rprim
+ blss 6$
+7$:
+; movl rprim,r1
+42$:
+ movl qprim,r0
+666$:
+ ret
+\f
+ .title vax_bn_add_words unsigned add of two arrays
+;
+; Richard Levitte 20-Nov-2000
+;
+; ULONG bn_add_words(ULONG r[], ULONG a[], ULONG b[], int n) {
+; ULONG c = 0;
+; int i;
+; for (i = 0; i < n; i++) <c,r[i]> = a[i] + b[i] + c;
+; return(c);
+; }
- movl r1,12(r3)
+r=4 ;(AP) r by reference (output)
+a=8 ;(AP) a by reference (input)
+b=12 ;(AP) b by reference (input)
+n=16 ;(AP) n by value (input)
- decl 16(ap)
- bleq noname.25
-noname.28:
- addl3 #16,r6,8(ap)
+ .psect code,nowrt
- addl3 #16,r5,12(ap)
+.entry bn_add_words,^m<r2,r3,r4,r5,r6>
- addl3 #16,r3,4(ap)
- brw noname.23
- tstl r0
-noname.25:
+ moval @r(ap),r2
+ moval @a(ap),r3
+ moval @b(ap),r4
+ movl n(ap),r5 ; assumed >0 by C code
+ clrl r0 ; c
- movl r4,r7
+ tstl r5 ; carry = 0
+ bleq 666$
-noname.22:
- movl r7,r0
- ret
- nop
+0$:
+ movl (r3)+,r6 ; carry untouched
+ addwc (r4)+,r6 ; carry used and touched
+ movl r6,(r2)+ ; carry untouched
+ sobgtr r5,0$ ; carry untouched
+ addwc #0,r0
+666$:
+ ret
\f
+ .title vax_bn_sub_words unsigned add of two arrays
+;
+; Richard Levitte 20-Nov-2000
+;
+; ULONG bn_sub_words(ULONG r[], ULONG a[], ULONG b[], int n) {
+; ULONG c = 0;
+; int i;
+; for (i = 0; i < n; i++) <c,r[i]> = a[i] - b[i] - c;
+; return(c);
+; }
-;r=4 ;(AP)
-;a=8 ;(AP)
-;b=12 ;(AP)
-;n=16 ;(AP) n by value (input)
+r=4 ;(AP) r by reference (output)
+a=8 ;(AP) a by reference (input)
+b=12 ;(AP) b by reference (input)
+n=16 ;(AP) n by value (input)
- .psect code,nowrt
-.entry BN_SUB_WORDS,^m<r2,r3,r4,r5,r6,r7>
+ .psect code,nowrt
- clrl r6
+.entry bn_sub_words,^m<r2,r3,r4,r5,r6>
- tstl 16(ap)
- bgtr noname.31
- clrl r7
- brw noname.32
- tstl r0
-noname.31:
+ moval @r(ap),r2
+ moval @a(ap),r3
+ moval @b(ap),r4
+ movl n(ap),r5 ; assumed >0 by C code
+ clrl r0 ; c
-noname.33:
+ tstl r5 ; carry = 0
+ bleq 666$
- movl 8(ap),r5
- movl (r5),r1
- movl 12(ap),r4
- movl (r4),r2
-
- movl 4(ap),r3
- subl3 r2,r1,r0
- subl2 r6,r0
- bicl3 #0,r0,(r3)
-
- cmpl r1,r2
- beql noname.34
- clrl r0
- cmpl r1,r2
- bgequ vcg.11
- incl r0
-vcg.11:
- movl r0,r6
-noname.34:
-
- decl 16(ap)
- bgtr gen.2
- brw noname.36
-gen.2:
-noname.35:
-
- movl 4(r5),r2
- movl 4(r4),r1
-
- subl3 r1,r2,r0
- subl2 r6,r0
- bicl3 #0,r0,4(r3)
-
- cmpl r2,r1
- beql noname.37
- clrl r0
- cmpl r2,r1
- bgequ vcg.12
- incl r0
-vcg.12:
- movl r0,r6
-noname.37:
-
- decl 16(ap)
- bleq noname.36
-noname.38:
-
- movl 8(r5),r1
- movl 8(r4),r2
-
- subl3 r2,r1,r0
- subl2 r6,r0
- bicl3 #0,r0,8(r3)
-
- cmpl r1,r2
- beql noname.39
- clrl r0
- cmpl r1,r2
- bgequ vcg.13
- incl r0
-vcg.13:
- movl r0,r6
-noname.39:
-
- decl 16(ap)
- bleq noname.36
-noname.40:
-
- movl 12(r5),r1
- movl 12(r4),r2
-
- subl3 r2,r1,r0
- subl2 r6,r0
- bicl3 #0,r0,12(r3)
-
- cmpl r1,r2
- beql noname.41
- clrl r0
- cmpl r1,r2
- bgequ vcg.14
- incl r0
-vcg.14:
- movl r0,r6
-noname.41:
-
- decl 16(ap)
- bleq noname.36
-noname.42:
-
- addl3 #16,r5,8(ap)
-
- addl3 #16,r4,12(ap)
-
- addl3 #16,r3,4(ap)
- brw noname.33
- tstl r0
-noname.36:
-
- movl r6,r7
-
-noname.32:
- movl r7,r0
- ret
- nop
+0$:
+ movl (r3)+,r6 ; carry untouched
+ sbwc (r4)+,r6 ; carry used and touched
+ movl r6,(r2)+ ; carry untouched
+ sobgtr r5,0$ ; carry untouched
+ addwc #0,r0
+666$:
+ ret
\f
;r=4 ;(AP)
ret
; For now, the code below doesn't work, so I end this prematurely.
-.end
-
- .title vax_bn_div64 division 64/32=>32
-;
-; r.l. 16-jan-1998
-;
-; unsigned int bn_div64(unsigned long h, unsigned long l, unsigned long d)
-; return <h,l>/d;
-;
-
- .psect code,nowrt
-
-h=4 ;(AP) by value (input)
-l=8 ;(AP) by value (input)
-d=12 ;(AP) by value (input)
-
-.entry bn_div64,^m<r2,r3,r4,r5,r6,r7,r8,r9>
-
- movl l(ap),r2 ; l
- movl h(ap),r3 ; h
- movl d(ap),r4 ; d
- clrl r5 ; q
- clrl r6 ; r
-
- ; Treat "negative" specially
- tstl r3
- blss 30$
-
- tstl r4
- beql 90$
-
- ediv r4,r2,r5,r6
- bvs 666$
-
- movl r5,r0
- ret
-
-30$:
- ; The theory here is to do some harmless shifting and a little
- ; bit of rounding (brackets are to designate when decimals are
- ; cut off):
- ;
- ; result = 2 * [ ([<h,0>/2] + [d/2]) / d ] + [ l / d ]
-
- movl #0,r7
- movl r3,r8 ; copy h
- ashq #-1,r7,r7 ; [<h,0>/2] => <r8,r7>
- bicl2 #^X80000000,r8 ; Remove "sign"
-
- movl r4,r9 ; copy d
- ashl #-1,r9,r9 ; [d/2] => r9
- bicl2 #^X80000000,r9 ; Remove "sign"
-
- addl2 r9,r7
- adwc #0,r8 ; [<h,0>/2] + [d/2] => <r8,r7>
-
- ediv r4,r7,r5,r6 ; [ ([<h,0>/2] + [d/2]) / d ] => <r5,r6>
- bvs 666$
-
- movl #0,r6
- ashq #1,r5,r5 ; 2 * [ ([<h,0>/2] + [d/2]) / d ] => r5
-
- movl #0,r3
- ediv r4,r2,r8,r9 ; [ l / d ] => <r8,r9>
-
- addl2 r8,r5 ;
- bcs 666$
-
- movl r5,r0
- ret
-
-90$:
- movl #-1,r0
- ret
-
-666$:
-
-
.end
projects / oweals / openssl.git / commitdiff