OSX/libsecurity_cryptkit/lib/giantPort_PPC.c

   1 /* Copyright (c) 1998,2011,2014 Apple Inc.  All Rights Reserved.
   2  *
   3  * NOTICE: USE OF THE MATERIALS ACCOMPANYING THIS NOTICE IS SUBJECT
   4  * TO THE TERMS OF THE SIGNED "FAST ELLIPTIC ENCRYPTION (FEE) REFERENCE
   5  * SOURCE CODE EVALUATION AGREEMENT" BETWEEN APPLE, INC. AND THE
   6  * ORIGINAL LICENSEE THAT OBTAINED THESE MATERIALS FROM APPLE,
   7  * INC.  ANY USE OF THESE MATERIALS NOT PERMITTED BY SUCH AGREEMENT WILL
   8  * EXPOSE YOU TO LIABILITY.
   9  ***************************************************************************
  10  *
  11  * giantPort_PPC.c - PPC-dependent giant definitions.
  12  *
  13  * Revision History
  14  * ----------------
  15  * 10/06/98             ap
  16  *      Changed to compile with C++.
  17  * 06 Apr 1998 at Apple
  18  *      Created.
  19  */
  20
  21 #include "feeDebug.h"
  22 #include "platform.h"
  23 #include "giantPort_PPC.h"
  24
  25 #if     !PPC_GIANT_PORT_INLINE
  26
  27
  28 /*
  29  * Multiple-precision arithmetic routines/macros.
  30  */
  31
  32 asm giantDigit giantAddDigits(
  33         register giantDigit dig1,
  34         register giantDigit dig2,
  35         register giantDigit *carry)     /* RETURNED, 0 or 1 */
  36
  37 {
  38         /*
  39          * dig1  : r3
  40          * dig2  : r4
  41          * carry : r5
  42          * sum   : r6
  43          */
  44
  45         /* sum = dig1 + dig2 */
  46         add     r6, dig1, dig2;
  47
  48         /* if((sum < dig1) || (sum < dig2)) */
  49         cmpl    crf0,0,r6,dig1
  50         bc      12,0,*+12
  51         cmpl    crf0,0,r6,dig2
  52         bc      4,0,*+16
  53
  54         /* *carry = 1; */
  55         li      r7,1
  56         stw     r7, 0(r5)
  57         b       *+12
  58
  59         /* else *carry = 0; */
  60         li      r7,0
  61         stw     r7, 0(r5)
  62
  63         /* return sum in r3 */
  64         mr.     r3,r6
  65         blr
  66 }
  67
  68 /*
  69  * Add a single digit value to a double digit accumulator in place.
  70  * Carry out of the MSD of the accumulator is not handled.
  71  * This should work any size giantDigits up to unsigned int.
  72  */
  73 asm void giantAddDouble(
  74         register giantDigit *accLow,            /* IN/OUT */
  75         register giantDigit *accHigh,           /* IN/OUT */
  76         register giantDigit val)
  77 {
  78         /*
  79          * r3 : accLow
  80          * r4 : accHi
  81          * r5 : val
  82          * r6 : sumLo
  83          * r7 : *accLow
  84          */
  85
  86         /* giantDigit sumLo = *accLow + val; */
  87         lwz     r7,0(accLow)
  88         add     r6,r7,val
  89
  90         /* if((sumLo < *accLow) || (sumLo < val)) { */
  91         cmpl     crf0,0,r6,r7
  92         bc       12,0,*+12
  93         cmpl     crf0,0,r6,val
  94         bc       4,0,*+16
  95
  96         /* (*accHigh)++; */
  97         lwz     r7, 0(accHigh)
  98         addi    r7,r7,1
  99         stw     r7, 0(accHigh)
 100
 101         /* *accLow = sumLo; */
 102         stw             r6,0(accLow)
 103         blr
 104 }
 105
 106 asm giantDigit giantSubDigits(
 107         register giantDigit a,
 108         register giantDigit b,
 109         register giantDigit *borrow)            /* RETURNED, 0 or 1 */
 110
 111 {
 112         /* a  : r3
 113            b  : r4
 114            borrow : r5
 115            diff   : r6 */
 116
 117         /* giantDigit diff = a - b; */
 118         subf    r6, b, a;
 119
 120         /* if(a < b) */
 121         cmpl    crf0,0,a,b
 122         bc      4,0,*+16
 123
 124         /* *borrow = 1; */
 125         li       r7,1
 126         stw      r7, 0(borrow)
 127         b        *+12
 128
 129         /* else *borrow = 0; */
 130         li       r7,0
 131         stw      r7, 0(borrow)
 132
 133         /* return diff in r3 */
 134         mr.      r3,r6
 135         blr
 136 }
 137
 138 asm void giantMulDigits(
 139         register giantDigit dig1,
 140         register giantDigit dig2,
 141         register giantDigit *lowProduct,        /* RETURNED, low digit */
 142         register giantDigit *hiProduct)         /* RETURNED, high digit */
 143 {
 144         /* r3 : dig1
 145            r4 : dig2
 146            r5 : lowProduct
 147            r6 : hiProduct */
 148
 149         /* dprod = (unsigned long long)dig1 * (unsigned long long)dig2; */
 150         mullw   r7, dig1, dig2  /* r7 = low(dig1 * dig2) */
 151         mulhwu  r8, dig1, dig2  /* r8 - hi(dig1 * dig2) */
 152
 153         /* *hiProduct = (giantDigit)(dprod >> GIANT_BITS_PER_DIGIT); */
 154         stw     r8, 0(hiProduct)
 155
 156         /* *lowProduct = (giantDigit)dprod; */
 157         stw     r7, 0(lowProduct)
 158         blr
 159 }
 160
 161 asm giantDigit VectorMultiply(
 162         register giantDigit plierDigit,         /* r3 */
 163         register giantDigit *candVector,        /* r4 */
 164         register unsigned candLength,           /* r5 */
 165         register giantDigit *prodVector)        /* r6 */
 166 {
 167         register unsigned candDex;                      /* index into multiplicandVector */
 168         register giantDigit lastCarry;
 169         register giantDigit prodLo;
 170         register giantDigit prodHi;
 171         register unsigned scr1;
 172         register unsigned sumLo;
 173
 174         fralloc
 175
 176     /* giantDigit lastCarry = 0; */
 177         li       lastCarry,0
 178
 179
 180         /* for(candDex=0; candDex<candLength; ++candDex) { */
 181         li       candDex,0
 182         b               _endLoop
 183
 184             /*
 185              * prod = *(candVector++) * plierDigit + *prodVector + lastCarry
 186              */
 187 _topLoop:
 188                 lwz      scr1,0(candVector)                             /* *candVector --> scr1 */
 189                 addi     candVector,candVector,4                /* candVector++ */
 190
 191                 mullw   prodLo,scr1,plierDigit  /* prodLo = low(*candVector * plierDigit) */
 192                 mulhwu  prodHi,scr1,plierDigit  /* prodHi = high(*candVector * plierDigit) */
 193
 194             /* giantAddDouble(&prodLo, &prodHi, *prodVector); */
 195                 lwz     scr1,0(prodVector)              /* *prodVector --> r9 */
 196                 add             sumLo,prodLo,scr1               /* prodLo + *prodVector --> sumLo */
 197                 cmpl    crf0,0,sumLo,prodLo             /* sumLo < prodLo? */
 198                 bc              12,0,_carry1
 199                 cmpl    crf0,0,sumLo,scr1               /* sumLo < *prodVector? */
 200                 bc              4,0,_noCar1
 201 _carry1:
 202                 addi    prodHi,prodHi,1                 /* prodHi++ */
 203 _noCar1:
 204                 mr.             prodLo,sumLo                    /* prodLo := sumLo */
 205
 206             /* giantAddDouble(&prodLo, &prodHi, lastCarry); */
 207                 add             sumLo,sumLo,lastCarry   /* sumLo += lastCarry */
 208                 cmpl    crf0,0,sumLo,prodLo             /* sumLo < prodLo? */
 209                 bc              12,0,_carry2
 210                 cmpl    crf0,0,sumLo,lastCarry  /* sumLo < lastCarry? */
 211                 bc              4,0,_noCar2
 212 _carry2:
 213                 addi    prodHi,prodHi,1                 /* prodHi++ */
 214 _noCar2:
 215                 mr.             prodLo,sumLo                    /* prodLo := sumLo */
 216
 217             /* *(prodVector++) = prodLo; */
 218                 stw      prodLo,0(prodVector)           /* prodLo --> *prodVector */
 219                 addi     prodVector,prodVector,4        /* prodVector++ */
 220
 221             /* lastCarry = prodHi; */
 222                 mr.             lastCarry,prodHi
 223
 224         /* } */
 225         addi     candDex,candDex,1                      /* candDex++ */
 226 _endLoop:
 227         cmpl     crf0,0,candDex,candLength      /* candDex < candLength? */
 228         bc       12,0,_topLoop
 229
 230         /* return lastCarry; */
 231         mr.      r3,lastCarry                           /* return lastCarry in r3 */
 232         frfree
 233         blr
 234 }
 235
 236 #endif  // PPC_GIANT_PORT_INLINE