* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (nextafterl): Remove

	unused ily variable.  Fix nextafterl on +-__LDBL_MAX__ and +-Inf.
	Remove unreachable code at the end.

	* sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c: Correct description of
	ldbl-128ibm in comment.
	(fpclassifyl): Correct classification of denormals.
	* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (nextafterl): Correct
	return value for MIN denormal. Rewrite using long double math too
	correctly handle denormals and canonicalize the results.

1 files changed, 54 insertions, 43 deletions

diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
index 4f8aa7dec1..39d0e6a5e3 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
@@ -35,7 +35,7 @@ static char rcsid[] = "$NetBSD: $";
 	long double x,y;
 #endif
 {
-	int64_t hx,hy,ihx,ihy,ilx,ily;
+	int64_t hx,hy,ihx,ihy,ilx;
 	u_int64_t lx,ly;
 
 	GET_LDOUBLE_WORDS64(hx,lx,x);
@@ -43,7 +43,6 @@ static char rcsid[] = "$NetBSD: $";
 	ihx = hx&0x7fffffffffffffffLL;		/* |hx| */
 	ilx = lx&0x7fffffffffffffffLL;		/* |lx| */
 	ihy = hy&0x7fffffffffffffffLL;		/* |hy| */
-	ily = ly&0x7fffffffffffffffLL;		/* |ly| */
 
 	if((((ihx&0x7ff0000000000000LL)==0x7ff0000000000000LL)&&
 	    ((ihx&0x000fffffffffffffLL)!=0)) ||   /* x is nan */
@@ -54,54 +53,66 @@ static char rcsid[] = "$NetBSD: $";
 	    return y;		/* x=y, return y */
 	if(ihx == 0 && ilx == 0) {			/* x == 0 */
 	    long double u;
-	    SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
-	    u = math_opt_barrier (u);
+	    hy = (hy & 0x8000000000000000ULL) | 1;
+	    SET_LDOUBLE_WORDS64(x,hy,0ULL);/* return +-minsubnormal */
+	    u = math_opt_barrier (x);
 	    u = u * u;
 	    math_force_eval (u);		/* raise underflow flag */
 	    return x;
 	}
-	if(ihx>=0) {			/* x > 0 */
-	    if(ihx>ihy||((ihx==ihy)&&(ilx>ily))) {	/* x > y, x -= ulp */
-
-	        if(ilx==0)
-		    hx--;
-		else
-		    lx--;
-	    } else {				/* x < y, x += ulp */
-	        if((hx==0x7fefffffffffffffLL)&&(lx==0x7c8ffffffffffffeLL))
-		  {
-		    SET_LDOUBLE_WORDS64(x,0x7ff0000000000000,0x8000000000000000);
-		    return x;
-		  }
-	        else if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL))
-		  {
-		    SET_LDOUBLE_WORDS64(x,0xfff0000000000000,0x8000000000000000);
-		    return x;
-		  }
-		else if((lx&0x7fffffffffffffff)==0) hx++;
-		else
-		  lx++;
+	
+	long double u;
+	if(x > y) {	/* x > y, x -= ulp */
+	    if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL))
+	      return x+x;	/* overflow, return -inf */
+	    if (hx >= 0x7ff0000000000000LL) {
+	      SET_LDOUBLE_WORDS64(u,0x7fefffffffffffffLL,0x7c8ffffffffffffeLL);
+	      return u;
 	    }
-	} else {				/* x < 0 */
-	    if(ihy>=0||ihx>ihy||((ihx==ihy)&&(ilx>ily))){/* x < y, x -= ulp */
-		if((lx&0x7fffffffffffffff)==0)
-		    hx--;
-		else
-		    lx--;
-	    } else {				/* x > y, x += ulp */
-		if((lx&0x7fffffffffffffff)==0) hx++;
-		else
-		  lx++;
+	    if(ihx <= 0x0360000000000000LL) {  /* x <= LDBL_MIN */
+	      u = math_opt_barrier (x);
+	      x -= __LDBL_DENORM_MIN__;
+	      if (ihx < 0x0360000000000000LL
+		  || (hx > 0 && (int64_t) lx <= 0)
+		  || (hx < 0 && (int64_t) lx > 1)) {
+		u = u * u;
+		math_force_eval (u);		/* raise underflow flag */
+	      }
+	      return x;
 	    }
+	    if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */
+	      SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL),0ULL);
+	      u *= 0x1.0000000000000p-105L;
+	    } else
+	      SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL)-0x0690000000000000LL,0ULL);
+	    return x - u;
+	} else {				/* x < y, x += ulp */
+	    if((hx==0x7fefffffffffffffLL)&&(lx==0x7c8ffffffffffffeLL))
+	      return x+x;	/* overflow, return +inf */
+	    if ((u_int64_t) hx >= 0xfff0000000000000ULL) {
+	      SET_LDOUBLE_WORDS64(u,0xffefffffffffffffLL,0xfc8ffffffffffffeLL);
+	      return u;
+	    }
+	    if(ihx <= 0x0360000000000000LL) {  /* x <= LDBL_MIN */
+	      u = math_opt_barrier (x);
+	      x += __LDBL_DENORM_MIN__;
+	      if (ihx < 0x0360000000000000LL
+		  || (hx > 0 && (int64_t) lx < 0 && lx != 0x8000000000000001LL)
+		  || (hx < 0 && (int64_t) lx >= 0)) {
+		u = u * u;
+		math_force_eval (u);		/* raise underflow flag */
+	      }
+	      if (x == 0.0L)	/* handle negative __LDBL_DENORM_MIN__ case */
+		x = -0.0L;
+	      return x;
+	    }
+	    if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */
+	      SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL),0ULL);
+	      u *= 0x1.0000000000000p-105L;
+	    } else
+	      SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL)-0x0690000000000000LL,0ULL);
+	    return x + u;
 	}
-	hy = hx&0x7ff0000000000000LL;
-	if(hy==0x7ff0000000000000LL) return x+x;/* overflow  */
-	if(hy==0) {
-	    long double u = x * x;		/* underflow */
-	    math_force_eval (u);		/* raise underflow flag */
-	}
-	SET_LDOUBLE_WORDS64(x,hx,lx);
-	return x;
 }
 strong_alias (__nextafterl, __nexttowardl)
 long_double_symbol (libm, __nextafterl, nextafterl);