PowerPC floating point little-endian [3 of 15]

http://sourceware.org/ml/libc-alpha/2013-08/msg00083.html

Further replacement of ieee854 macros and unions.  These files also
have some optimisations for comparison against 0.0L, infinity and nan.
Since the ABI specifies that the high double of an IBM long double
pair is the value rounded to double, a high double of 0.0 means the
low double must also be 0.0.  The ABI also says that infinity and
nan are encoded in the high double, with the low double unspecified.
This means that tests for 0.0L, +/-Infinity and +/-NaN need only check
the high double.

	* sysdeps/ieee754/ldbl-128ibm/e_atan2l.c (__ieee754_atan2l): Rewrite
	all uses of ieee854 long double macros and unions.  Simplify tests
	for long doubles that are fully specified by the high double.
	* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (__ieee754_gammal_r):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c (__ieee754_ilogbl): Likewise.
	Remove dead code too.
	* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
	(__ieee754_ynl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_log10l.c (__ieee754_log10l): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_logl.c (__ieee754_logl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Likewise.
	Remove dead code too.
	* sysdeps/ieee754/ldbl-128ibm/k_tanl.c (__kernel_tanl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_expm1l.c (__expm1l): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_frexpl.c (__frexpl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_isinf_nsl.c (__isinf_nsl): Likewise.
	Simplify.
	* sysdeps/ieee754/ldbl-128ibm/s_isinfl.c (___isinfl): Likewise.
	Simplify.
	* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (__log1pl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_modfl.c (__modfl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (__nextafterl): Likewise.
	Comment on variable precision.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_remquol.c (__remquol): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_scalblnl.c (__scalblnl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c (__scalbnl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c (__tanhl): Likewise.
	* sysdeps/powerpc/fpu/libm-test-ulps: Adjust tan_towardzero ulps.

1 files changed, 35 insertions, 22 deletions

diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
index 7e581274a3..c050944c0c 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
@@ -30,27 +30,28 @@ static char rcsid[] = "$NetBSD: $";
 
 long double __nextafterl(long double x, long double y)
 {
-	int64_t hx,hy,ihx,ihy,ilx;
-	u_int64_t lx;
-	u_int64_t ly __attribute__ ((unused));
+	int64_t hx,hy,ihx,ihy;
+	uint64_t lx;
+	double xhi, xlo, yhi;
 
-	GET_LDOUBLE_WORDS64(hx,lx,x);
-	GET_LDOUBLE_WORDS64(hy,ly,y);
+	ldbl_unpack (x, &xhi, &xlo);
+	EXTRACT_WORDS64 (hx, xhi);
+	EXTRACT_WORDS64 (lx, xlo);
+	yhi = ldbl_high (y);
+	EXTRACT_WORDS64 (hy, yhi);
 	ihx = hx&0x7fffffffffffffffLL;		/* |hx| */
-	ilx = lx&0x7fffffffffffffffLL;		/* |lx| */
 	ihy = hy&0x7fffffffffffffffLL;		/* |hy| */
 
-	if((((ihx&0x7ff0000000000000LL)==0x7ff0000000000000LL)&&
-	    ((ihx&0x000fffffffffffffLL)!=0)) ||   /* x is nan */
-	   (((ihy&0x7ff0000000000000LL)==0x7ff0000000000000LL)&&
-	    ((ihy&0x000fffffffffffffLL)!=0)))     /* y is nan */
+	if((ihx>0x7ff0000000000000LL) ||	/* x is nan */
+	   (ihy>0x7ff0000000000000LL))		/* y is nan */
 	    return x+y; /* signal the nan */
 	if(x==y)
 	    return y;		/* x=y, return y */
-	if(ihx == 0 && ilx == 0) {			/* x == 0 */
-	    long double u;
+	if(ihx == 0) {				/* x == 0 */
+	    long double u;			/* return +-minsubnormal */
 	    hy = (hy & 0x8000000000000000ULL) | 1;
-	    SET_LDOUBLE_WORDS64(x,hy,0ULL);/* return +-minsubnormal */
+	    INSERT_WORDS64 (yhi, hy);
+	    x = yhi;
 	    u = math_opt_barrier (x);
 	    u = u * u;
 	    math_force_eval (u);		/* raise underflow flag */
@@ -59,10 +60,16 @@ long double __nextafterl(long double x, long double y)
 
 	long double u;
 	if(x > y) {	/* x > y, x -= ulp */
+	    /* This isn't the largest magnitude correctly rounded
+	       long double as you can see from the lowest mantissa
+	       bit being zero.  It is however the largest magnitude
+	       long double with a 106 bit mantissa, and nextafterl
+	       is insane with variable precision.  So to make
+	       nextafterl sane we assume 106 bit precision.  */
 	    if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL))
 	      return x+x;	/* overflow, return -inf */
 	    if (hx >= 0x7ff0000000000000LL) {
-	      SET_LDOUBLE_WORDS64(u,0x7fefffffffffffffLL,0x7c8ffffffffffffeLL);
+	      u = 0x1.fffffffffffff7ffffffffffff8p+1023L;
 	      return u;
 	    }
 	    if(ihx <= 0x0360000000000000LL) {  /* x <= LDBL_MIN */
@@ -77,16 +84,19 @@ long double __nextafterl(long double x, long double y)
 	      return x;
 	    }
 	    if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */
-	      SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL),0ULL);
+	      INSERT_WORDS64 (yhi, hx & (0x7ffLL<<52));
+	      u = yhi;
 	      u *= 0x1.0000000000000p-105L;
-	    } else
-	      SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL)-0x0690000000000000LL,0ULL);
+	    } else {
+	      INSERT_WORDS64 (yhi, (hx & (0x7ffLL<<52))-(0x069LL<<52));
+	      u = yhi;
+	    }
 	    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);
+	    if ((uint64_t) hx >= 0xfff0000000000000ULL) {
+	      u = -0x1.fffffffffffff7ffffffffffff8p+1023L;
 	      return u;
 	    }
 	    if(ihx <= 0x0360000000000000LL) {  /* x <= LDBL_MIN */
@@ -103,10 +113,13 @@ long double __nextafterl(long double x, long double y)
 	      return x;
 	    }
 	    if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */
-	      SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL),0ULL);
+	      INSERT_WORDS64 (yhi, hx & (0x7ffLL<<52));
+	      u = yhi;
 	      u *= 0x1.0000000000000p-105L;
-	    } else
-	      SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL)-0x0690000000000000LL,0ULL);
+	    } else {
+	      INSERT_WORDS64 (yhi, (hx & (0x7ffLL<<52))-(0x069LL<<52));
+	      u = yhi;
+	    }
 	    return x + u;
 	}
 }