The IRIX fix. Asm recap and corresponding declation.

[openssl.git] / crypto / bn / bn_div.c

diff --git a/crypto/bn/bn_div.c b/crypto/bn/bn_div.c
index 31062b7db263cd6a180674f1bc0f2424f07e6c46..d0b68dc246e7c6d8f24242c1e0db9fa8d6b4be75 100644 (file)
--- a/crypto/bn/bn_div.c
+++ b/crypto/bn/bn_div.c
@@ -61,6 +61,7 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
+
 /* The old slow way */
 #if 0
 int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
@@ -126,7 +127,8 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
 
 #else
 
-#if !defined(NO_ASM) && !defined(PEDANTIC) && !defined(BN_DIV3W)
+#if !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM) \
+    && !defined(PEDANTIC) && !defined(BN_DIV3W)
 # if defined(__GNUC__) && __GNUC__>=2
 #  if defined(__i386)
    /*
@@ -150,8 +152,16 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
 #  define REMAINDER_IS_ALREADY_CALCULATED
 #  endif /* __<cpu> */
 # endif /* __GNUC__ */
-#endif /* NO_ASM */
+#endif /* OPENSSL_NO_ASM */
+
 
+/* BN_div computes  dv := num / divisor,  rounding towards zero, and sets up
+ * rm  such that  dv*divisor + rm = num  holds.
+ * Thus:
+ *     dv->neg == num->neg ^ divisor->neg  (unless the result is zero)
+ *     rm->neg == num->neg                 (unless the remainder is zero)
+ * If 'dv' or 'rm' is NULL, the respective value is not returned.
+ */
 int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
           BN_CTX *ctx)
        {
@@ -180,13 +190,13 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
 
        BN_CTX_start(ctx);
        tmp=BN_CTX_get(ctx);
-       tmp->neg=0;
        snum=BN_CTX_get(ctx);
        sdiv=BN_CTX_get(ctx);
        if (dv == NULL)
                res=BN_CTX_get(ctx);
        else    res=dv;
-       if (res == NULL) goto err;
+       if (sdiv == NULL || res == NULL) goto err;
+       tmp->neg=0;
 
        /* First we normalise the numbers */
        norm_shift=BN_BITS2-((BN_num_bits(divisor))%BN_BITS2);
@@ -205,7 +215,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
        BN_init(&wnum);
        wnum.d=  &(snum->d[loop]);
        wnum.top= div_n;
-       wnum.max= snum->max+1; /* a bit of a lie */
+       wnum.dmax= snum->dmax+1; /* a bit of a lie */
 
        /* Get the top 2 words of sdiv */
        /* i=sdiv->top; */
@@ -232,12 +242,15 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
                }
        else
                res->top--;
+       if (res->top == 0)
+               res->neg = 0;
        resp--;
 
        for (i=0; i<loop-1; i++)
                {
                BN_ULONG q,l0;
-#ifdef BN_DIV3W
+#if defined(BN_DIV3W) && !defined(OPENSSL_NO_ASM)
+               BN_ULONG bn_div_3_words(BN_ULONG*,BN_ULONG,BN_ULONG);
                q=bn_div_3_words(wnump,d1,d0);
 #else
                BN_ULONG n0,n1,rem=0;
@@ -330,8 +343,13 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
                }
        if (rm != NULL)
                {
+               /* Keep a copy of the neg flag in num because if rm==num
+                * BN_rshift() will overwrite it.
+                */
+               int neg = num->neg;
                BN_rshift(rm,snum,norm_shift);
-               rm->neg=num->neg;
+               if (!BN_is_zero(rm))
+                       rm->neg = neg;
                }
        BN_CTX_end(ctx);
        return(1);
@@ -341,40 +359,3 @@ err:
        }
 
 #endif
-
-/* rem != m */
-int BN_mod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
-       {
-#if 0 /* The old slow way */
-       int i,nm,nd;
-       BIGNUM *dv;
-
-       if (BN_ucmp(m,d) < 0)
-               return((BN_copy(rem,m) == NULL)?0:1);
-
-       BN_CTX_start(ctx);
-       dv=BN_CTX_get(ctx);
-
-       if (!BN_copy(rem,m)) goto err;
-
-       nm=BN_num_bits(rem);
-       nd=BN_num_bits(d);
-       if (!BN_lshift(dv,d,nm-nd)) goto err;
-       for (i=nm-nd; i>=0; i--)
-               {
-               if (BN_cmp(rem,dv) >= 0)
-                       {
-                       if (!BN_sub(rem,rem,dv)) goto err;
-                       }
-               if (!BN_rshift1(dv,dv)) goto err;
-               }
-       BN_CTX_end(ctx);
-       return(1);
- err:
-       BN_CTX_end(ctx);
-       return(0);
-#else
-       return(BN_div(NULL,rem,m,d,ctx));
-#endif
-       }
-