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authorAlan Modra <amodra@gmail.com>2013-08-17 18:24:58 +0930
committerAlan Modra <amodra@gmail.com>2013-10-04 10:32:36 +0930
commit765714cafcad7e6168518c61111f07bd955a9fee (patch)
tree27c4ab59ddc279114f3d0b7064a47317cb91c3ca /sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c
parent4ebd120cd983c8d2ac7a234884b3ac6805d82973 (diff)
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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.
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c16
1 files changed, 7 insertions, 9 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c b/sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c
index 55f87ed422..aeace7c977 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c
@@ -31,26 +31,24 @@ static char rcsid[] = "$NetBSD: $";
 
 int __ieee754_ilogbl(long double x)
 {
-	int64_t hx,lx;
+	int64_t hx;
 	int ix;
+	double xhi;
 
-	GET_LDOUBLE_WORDS64(hx,lx,x);
+	xhi = ldbl_high (x);
+	EXTRACT_WORDS64 (hx, xhi);
 	hx &= 0x7fffffffffffffffLL;
 	if(hx <= 0x0010000000000000LL) {
-	    if((hx|(lx&0x7fffffffffffffffLL))==0)
+	    if(hx==0)
 		return FP_ILOGB0;	/* ilogbl(0) = FP_ILOGB0 */
 	    else			/* subnormal x */
-		if(hx==0) {
-		    for (ix = -1043; lx>0; lx<<=1) ix -=1;
-		} else {
-		    for (ix = -1022, hx<<=11; hx>0; hx<<=1) ix -=1;
-		}
+		for (ix = -1022, hx<<=11; hx>0; hx<<=1) ix -=1;
 	    return ix;
 	}
 	else if (hx<0x7ff0000000000000LL) return (hx>>52)-0x3ff;
 	else if (FP_ILOGBNAN != INT_MAX) {
 	    /* ISO C99 requires ilogbl(+-Inf) == INT_MAX.  */
-	    if (((hx^0x7ff0000000000000LL)|lx) == 0)
+	    if (hx==0x7ff0000000000000LL)
 		return INT_MAX;
 	}
 	return FP_ILOGBNAN;