Bug 1194073 - removing mp_sqrt, r=rbarnes

try: -b do -p linux64-asan -u cipher

--HG--
extra : rebase_source : d2262d0dc6ca0ed3ca1a153a4ef6a9769612758c

lib/freebl/mpi/README

@@ -234,7 +234,6 @@ mp_div(a, b, q, r)      - computes q, r such that a = bq + r
 mp_div_2d(a, d, q, r)   - computes q = a / 2^d, r = a % 2^d
 mp_expt(a, b, c)        - computes c = a ** b
 mp_2expt(a, k)          - computes a = 2^k
-mp_sqrt(a, c)           - computes c = floor(sqrt(a))
 
 The mp_div_2d() function efficiently computes division by powers of
 two.  Either the q or r parameter may be NULL, in which case that

lib/freebl/mpi/mpi-test.c

@@ -1181,39 +1181,6 @@ test_2expt(void)
 
 /*------------------------------------------------------------------------*/
 
-int
-test_sqrt(void)
-{
-    mp_int a;
-    int res = 0;
-
-    mp_init(&a);
-    mp_read_radix(&a, mp9, 16);
-    mp_sqrt(&a, &a);
-    mp_toradix(&a, g_intbuf, 16);
-
-    if (strcmp(g_intbuf, t_mp9) != 0) {
-        reason("error: computed %s, expected %s\n", g_intbuf, t_mp9);
-        res = 1;
-        goto CLEANUP;
-    }
-
-    mp_read_radix(&a, mp15, 16);
-    mp_sqrt(&a, &a);
-    mp_toradix(&a, g_intbuf, 16);
-
-    if (strcmp(g_intbuf, t_mp15) != 0) {
-        reason("error: computed %s, expected %s\n", g_intbuf, t_mp15);
-        res = 1;
-    }
-
-CLEANUP:
-    mp_clear(&a);
-    return res;
-}
-
-/*------------------------------------------------------------------------*/
-
 int
 test_mod_d(void)
 {

lib/freebl/mpi/mpi.c

@@ -1297,88 +1297,6 @@ mp_mod_d(const mp_int *a, mp_digit d, mp_digit *c)
 
 /* }}} */
 
-/* {{{ mp_sqrt(a, b) */
-
-/*
-  mp_sqrt(a, b)
-
-  Compute the integer square root of a, and store the result in b.
-  Uses an integer-arithmetic version of Newton's iterative linear
-  approximation technique to determine this value; the result has the
-  following two properties:
-
-     b^2 <= a
-     (b+1)^2 >= a
-
-  It is a range error to pass a negative value.
- */
-mp_err
-mp_sqrt(const mp_int *a, mp_int *b)
-{
-    mp_int x, t;
-    mp_err res;
-    mp_size used;
-
-    ARGCHK(a != NULL && b != NULL, MP_BADARG);
-
-    /* Cannot take square root of a negative value */
-    if (SIGN(a) == NEG)
-        return MP_RANGE;
-
-    /* Special cases for zero and one, trivial     */
-    if (mp_cmp_d(a, 1) <= 0)
-        return mp_copy(a, b);
-
-    /* Initialize the temporaries we'll use below  */
-    if ((res = mp_init_size(&t, USED(a))) != MP_OKAY)
-        return res;
-
-    /* Compute an initial guess for the iteration as a itself */
-    if ((res = mp_init_copy(&x, a)) != MP_OKAY)
-        goto X;
-
-    used = MP_USED(&x);
-    if (used > 1) {
-        s_mp_rshd(&x, used / 2);
-    }
-
-    for (;;) {
-        /* t = (x * x) - a */
-        if ((res = mp_copy(&x, &t)) != MP_OKAY ||
-            (res = mp_sqr(&t, &t)) != MP_OKAY ||
-            (res = mp_sub(&t, a, &t)) != MP_OKAY)
-            goto CLEANUP;
-
-        /* t = t / 2x       */
-        s_mp_mul_2(&x);
-        if ((res = mp_div(&t, &x, &t, NULL)) != MP_OKAY)
-            goto CLEANUP;
-        s_mp_div_2(&x);
-
-        /* Terminate the loop, if the quotient is zero */
-        if (mp_cmp_z(&t) == MP_EQ)
-            break;
-
-        /* x = x - t       */
-        if ((res = mp_sub(&x, &t, &x)) != MP_OKAY)
-            goto CLEANUP;
-    }
-
-    /* Copy result to output parameter */
-    MP_CHECKOK(mp_sub_d(&x, 1, &x));
-    s_mp_exch(&x, b);
-
-CLEANUP:
-    mp_clear(&x);
-X:
-    mp_clear(&t);
-
-    return res;
-
-} /* end mp_sqrt() */
-
-/* }}} */
-
 /* }}} */
 
 /*------------------------------------------------------------------------*/

lib/freebl/mpi/mpi.h

@@ -196,7 +196,6 @@ mp_err mp_div(const mp_int *a, const mp_int *b, mp_int *q, mp_int *r);
 mp_err mp_div_2d(const mp_int *a, mp_digit d, mp_int *q, mp_int *r);
 mp_err mp_expt(mp_int *a, mp_int *b, mp_int *c);
 mp_err mp_2expt(mp_int *a, mp_digit k);
-mp_err mp_sqrt(const mp_int *a, mp_int *b);
 
 /* Modular arithmetic      */
 #if MP_MODARITH

lib/freebl/mpi/tests/mptest-3.c

@@ -17,7 +17,6 @@
 
 #include "mpi.h"
 
-#define SQRT 1 /* define nonzero to get square-root test  */
 #define EXPT 0 /* define nonzero to get exponentiate test */
 
 int
@@ -97,21 +96,6 @@ main(int argc, char *argv[])
     mp_print(&c, stdout);
     fputc('\n', stdout);
 
-#if SQRT
-    printf("\nc = sqrt(a)\n");
-    if ((res = mp_sqrt(&a, &c)) != MP_OKAY) {
-        printf("mp_sqrt: %s\n", mp_strerror(res));
-    } else {
-        printf("c = ");
-        mp_print(&c, stdout);
-        fputc('\n', stdout);
-        mp_sqr(&c, &c);
-        printf("c^2 = ");
-        mp_print(&c, stdout);
-        fputc('\n', stdout);
-    }
-#endif
-
     mp_clear(&d);
     mp_clear(&c);
     mp_clear(&b);