From d2f1ffa076a99c3f6fdd282de338b67402c06312 Mon Sep 17 00:00:00 2001
From: mdw <mdw>
Date: Wed, 1 Dec 2004 01:30:06 +0000
Subject: [PATCH] Better reduction.

---
 f-niceprime.c | 9 +++++----
 f-prime.c     | 8 ++++----
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/f-niceprime.c b/f-niceprime.c
index ce96977..4c9deea 100644
--- a/f-niceprime.c
+++ b/f-niceprime.c
@@ -99,20 +99,20 @@ static mp *fsqrt(field *ff, mp *d, mp *x) {
 
 static mp *fdbl(field *ff, mp *d, mp *x) {
   fctx_niceprime *f = (fctx_niceprime *)ff; d = mp_lsl(d, x, 1);
-  if (MP_CMP(d, >, f->r.p)) d = mp_sub(d, d, f->r.p);
+  if (MP_CMP(d, >=, f->r.p)) d = mp_sub(d, d, f->r.p);
   return (d);
 }
 
 static mp *ftpl(field *ff, mp *d, mp *x) {
   fctx_niceprime *f = (fctx_niceprime *)ff; MP_DEST(d, MP_LEN(x) + 1, x->f);
-  MPX_UMULN(d->v, d->vl, x->v, x->vl, 3);
-  while (MP_CMP(d, >, f->r.p)) d = mp_sub(d, d, f->r.p);
+  MPX_UMULN(d->v, d->vl, x->v, x->vl, 3); d->f &= ~MP_UNDEF;
+  while (MP_CMP(d, >=, f->r.p)) d = mp_sub(d, d, f->r.p);
   return (d);
 }
 
 static mp *fqdl(field *ff, mp *d, mp *x) {
   fctx_niceprime *f = (fctx_niceprime *)ff; d = mp_lsl(d, x, 2);
-  while (MP_CMP(d, >, f->r.p)) d = mp_sub(d, d, f->r.p);
+  while (MP_CMP(d, >=, f->r.p)) d = mp_sub(d, d, f->r.p);
   return (d);
 }
 
@@ -157,6 +157,7 @@ field *field_niceprime(mp *p)
     return (0);
   }
   f->f.m = f->r.p;
+  f->f.q = f->r.p;
   return (&f->f);
 }
 
diff --git a/f-prime.c b/f-prime.c
index f2fd7eb..422c386 100644
--- a/f-prime.c
+++ b/f-prime.c
@@ -111,20 +111,20 @@ static mp *fsqrt(field *ff, mp *d, mp *x) {
 
 static mp *fdbl(field *ff, mp *d, mp *x) {
   fctx_prime *f = (fctx_prime *)ff; d = mp_lsl(d, x, 1);
-  if (MP_CMP(d, >, f->mm.m)) d = mp_sub(d, d, f->mm.m);
+  if (MP_CMP(d, >=, f->mm.m)) d = mp_sub(d, d, f->mm.m);
   return (d);
 }
 
 static mp *ftpl(field *ff, mp *d, mp *x) {
   fctx_prime *f = (fctx_prime *)ff; MP_DEST(d, MP_LEN(x) + 1, x->f);
-  MPX_UMULN(d->v, d->vl, x->v, x->vl, 3);
-  while (MP_CMP(d, >, f->mm.m)) d = mp_sub(d, d, f->mm.m);
+  MPX_UMULN(d->v, d->vl, x->v, x->vl, 3); d->f &= ~MP_UNDEF;
+  while (MP_CMP(d, >=, f->mm.m)) d = mp_sub(d, d, f->mm.m);
   return (d);
 }
 
 static mp *fqdl(field *ff, mp *d, mp *x) {
   fctx_prime *f = (fctx_prime *)ff; d = mp_lsl(d, x, 2);
-  while (MP_CMP(d, >, f->mm.m)) d = mp_sub(d, d, f->mm.m);
+  while (MP_CMP(d, >=, f->mm.m)) d = mp_sub(d, d, f->mm.m);
   return (d);
 }
 
-- 
2.11.0