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diff -Naurd mpfr-3.1.3-a/PATCHES mpfr-3.1.3-b/PATCHES
--- mpfr-3.1.3-a/PATCHES 2015-10-29 13:47:46.735901185 +0000
+++ mpfr-3.1.3-b/PATCHES 2015-10-29 13:47:46.763900609 +0000
@@ -0,0 +1 @@
+divhigh-basecase
diff -Naurd mpfr-3.1.3-a/VERSION mpfr-3.1.3-b/VERSION
--- mpfr-3.1.3-a/VERSION 2015-07-17 08:58:21.118986898 +0000
+++ mpfr-3.1.3-b/VERSION 2015-10-29 13:47:46.763900609 +0000
@@ -1 +1 @@
-3.1.3-p4
+3.1.3-p5
diff -Naurd mpfr-3.1.3-a/src/mpfr.h mpfr-3.1.3-b/src/mpfr.h
--- mpfr-3.1.3-a/src/mpfr.h 2015-07-17 08:58:21.114986979 +0000
+++ mpfr-3.1.3-b/src/mpfr.h 2015-10-29 13:47:46.759900692 +0000
@@ -27,7 +27,7 @@
#define MPFR_VERSION_MAJOR 3
#define MPFR_VERSION_MINOR 1
#define MPFR_VERSION_PATCHLEVEL 3
-#define MPFR_VERSION_STRING "3.1.3-p4"
+#define MPFR_VERSION_STRING "3.1.3-p5"
/* Macros dealing with MPFR VERSION */
#define MPFR_VERSION_NUM(a,b,c) (((a) << 16L) | ((b) << 8) | (c))
diff -Naurd mpfr-3.1.3-a/src/mulders.c mpfr-3.1.3-b/src/mulders.c
--- mpfr-3.1.3-a/src/mulders.c 2015-06-19 19:55:10.000000000 +0000
+++ mpfr-3.1.3-b/src/mulders.c 2015-10-29 13:47:46.751900855 +0000
@@ -236,9 +236,10 @@
that in addition to the limb np[n-1] to reduce, we have at least 2
extra limbs, thus accessing np[n-3] is valid. */
- /* warning: we can have np[n-1]=d1 and np[n-2]=d0, but since {np,n} < D,
- the largest possible partial quotient is B-1 */
- if (MPFR_UNLIKELY(np[n - 1] == d1 && np[n - 2] == d0))
+ /* Warning: we can have np[n-1]>d1 or (np[n-1]=d1 and np[n-2]>=d0) here,
+ since we truncate the divisor at each step, but since {np,n} < D
+ originally, the largest possible partial quotient is B-1. */
+ if (MPFR_UNLIKELY(np[n-1] > d1 || (np[n-1] == d1 && np[n-2] >= d0)))
q2 = ~ (mp_limb_t) 0;
else
udiv_qr_3by2 (q2, q1, q0, np[n - 1], np[n - 2], np[n - 3],
diff -Naurd mpfr-3.1.3-a/src/version.c mpfr-3.1.3-b/src/version.c
--- mpfr-3.1.3-a/src/version.c 2015-07-17 08:58:21.118986898 +0000
+++ mpfr-3.1.3-b/src/version.c 2015-10-29 13:47:46.763900609 +0000
@@ -25,5 +25,5 @@
const char *
mpfr_get_version (void)
{
- return "3.1.3-p4";
+ return "3.1.3-p5";
}
diff -Naurd mpfr-3.1.3-a/tests/tdiv.c mpfr-3.1.3-b/tests/tdiv.c
--- mpfr-3.1.3-a/tests/tdiv.c 2015-06-19 19:55:10.000000000 +0000
+++ mpfr-3.1.3-b/tests/tdiv.c 2015-10-29 13:47:46.751900855 +0000
@@ -1099,6 +1099,69 @@
mpfr_set_emax (old_emax);
}
+/* Bug in mpfr_divhigh_n_basecase when all limbs of q (except the most
+ significant one) are B-1 where B=2^GMP_NUMB_BITS. Since we truncate
+ the divisor at each step, it might happen at some point that
+ (np[n-1],np[n-2]) > (d1,d0), and not only the equality.
+ Reported by Ricky Farr
+ <https://sympa.inria.fr/sympa/arc/mpfr/2015-10/msg00023.html>
+ To get a failure, a MPFR_DIVHIGH_TAB entry below the MPFR_DIV_THRESHOLD
+ limit must have a value 0. With most mparam.h files, this cannot occur. */
+static void
+test_20151023 (void)
+{
+ mpfr_prec_t p;
+ mpfr_t n, d, q, q0;
+ int inex, i;
+
+ for (p = GMP_NUMB_BITS; p <= 2000; p++)
+ {
+ mpfr_init2 (n, 2*p);
+ mpfr_init2 (d, p);
+ mpfr_init2 (q, p);
+ mpfr_init2 (q0, GMP_NUMB_BITS);
+
+ /* generate a random divisor of p bits */
+ mpfr_urandomb (d, RANDS);
+ /* generate a random quotient of GMP_NUMB_BITS bits */
+ mpfr_urandomb (q0, RANDS);
+ /* zero-pad the quotient to p bits */
+ inex = mpfr_prec_round (q0, p, MPFR_RNDN);
+ MPFR_ASSERTN(inex == 0);
+
+ for (i = 0; i < 3; i++)
+ {
+ /* i=0: try with the original quotient xxx000...000
+ i=1: try with the original quotient minus one ulp
+ i=2: try with the original quotient plus one ulp */
+ if (i == 1)
+ mpfr_nextbelow (q0);
+ else if (i == 2)
+ {
+ mpfr_nextabove (q0);
+ mpfr_nextabove (q0);
+ }
+
+ inex = mpfr_mul (n, d, q0, MPFR_RNDN);
+ MPFR_ASSERTN(inex == 0);
+ mpfr_nextabove (n);
+ mpfr_div (q, n, d, MPFR_RNDN);
+ MPFR_ASSERTN(mpfr_cmp (q, q0) == 0);
+
+ inex = mpfr_mul (n, d, q0, MPFR_RNDN);
+ MPFR_ASSERTN(inex == 0);
+ mpfr_nextbelow (n);
+ mpfr_div (q, n, d, MPFR_RNDN);
+ MPFR_ASSERTN(mpfr_cmp (q, q0) == 0);
+ }
+
+ mpfr_clear (n);
+ mpfr_clear (d);
+ mpfr_clear (q);
+ mpfr_clear (q0);
+ }
+}
+
#define TEST_FUNCTION test_div
#define TWO_ARGS
#define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), randlimb () % 100, RANDS)
@@ -1219,6 +1282,7 @@
consistency ();
test_20070603 ();
test_20070628 ();
+ test_20151023 ();
test_generic (2, 800, 50);
test_extreme ();
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