svn commit: r238784 - in head/lib/msun: ld128 ld80

[Steve Kargl]

Author: kargl
Date: Thu Jul 26 04:05:08 2012
New Revision: 238784
URL: http://svn.freebsd.org/changeset/base/238784

Log:
  Replace the macro name NUM with INTERVALS.  This change provides
  compatibility with the INTERVALS macro used in the soon-to-be-commmitted
  expm1l() and someday-to-be-committed log*l() functions.
  
  Add a comment into ld128/s_expl.c noting at gcc issue that was
  deleted when rewriting ld80/e_expl.c as ld128/s_expl.c.
  
  Requested by:	bde
  Approved by:	das (mentor)

Modified:
  head/lib/msun/ld128/s_expl.c
  head/lib/msun/ld80/s_expl.c

Modified: head/lib/msun/ld128/s_expl.c
==============================================================================
--- head/lib/msun/ld128/s_expl.c	Thu Jul 26 03:59:33 2012	(r238783)
+++ head/lib/msun/ld128/s_expl.c	Thu Jul 26 04:05:08 2012	(r238784)
@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
 
 #define	BIAS	(LDBL_MAX_EXP - 1)
 
+/* XXX Prevent gcc from erroneously constant folding this: */
 static volatile const long double twom10000 = 0x1p-10000L, tiny = 0x1p-10000L;
 
 static const long double
@@ -57,12 +58,12 @@ P9 = 2.755731922401038678178761995444688
 P10 = 2.75573236172670046201884000197885520e-7L,
 P11 = 2.50517544183909126492878226167697856e-8L;
 
-#define	NUM		128
+#define	INTERVALS		128
 
 static const struct {
 	long double	hi;
 	long double	lo;
-} s[NUM] = {
+} s[INTERVALS] = {
 	0x1p0L, 0x0p0L,
 	0x1.0163da9fb33356d84a66aep0L, 0x3.36dcdfa4003ec04c360be2404078p-92L,
 	0x1.02c9a3e778060ee6f7cacap0L, 0x4.f7a29bde93d70a2cabc5cb89ba10p-92L,
@@ -226,8 +227,8 @@ expl(long double x)
 
 	fn = x * INV_L + 0x1.8p112 - 0x1.8p112;
 	n  = (int)fn;
-	n2 = (unsigned)n % NUM;		/* Tang's j. */
-	k = (n - n2) / NUM;
+	n2 = (unsigned)n % INTERVALS;		/* Tang's j. */
+	k = (n - n2) / INTERVALS;
 	r1 = x - fn * L1;
 	r2 = -fn * L2;
 

Modified: head/lib/msun/ld80/s_expl.c
==============================================================================
--- head/lib/msun/ld80/s_expl.c	Thu Jul 26 03:59:33 2012	(r238783)
+++ head/lib/msun/ld80/s_expl.c	Thu Jul 26 04:05:08 2012	(r238784)
@@ -36,7 +36,7 @@ __FBSDID("$FreeBSD$");
  *   in IEEE floating-point arithmetic," ACM Trans. Math. Soft., 15,
  *   144-157 (1989).
  *
- * where the 32 table entries have been expanded to NUM (see below).
+ * where the 32 table entries have been expanded to INTERVALS (see below).
  */
 
 #include <float.h>
@@ -65,9 +65,9 @@ u_threshold = LD80C(0xb21dfe7f09e2baa9, 
 
 static const double __aligned(64)
 /*
- * ln2/NUM = L1+L2 (hi+lo decomposition for multiplication).  L1 must have
- * at least 22 (= log2(|LDBL_MIN_EXP-extras|) + log2(NUM)) lowest bits zero
- * so that multiplication of it by n is exact.
+ * ln2/INTERVALS = L1+L2 (hi+lo decomposition for multiplication).  L1 must
+ * have at least 22 (= log2(|LDBL_MIN_EXP-extras|) + log2(INTERVALS)) lowest
+ * bits zero so that multiplication of it by n is exact.
  */
 L1 =  5.4152123484527692e-3,		/*  0x162e42ff000000.0p-60 */
 L2 = -3.2819649005320973e-13,		/* -0x1718432a1b0e26.0p-94 */
@@ -75,7 +75,7 @@ INV_L = 1.8466496523378731e+2,		/*  0x17
 /*
  * Domain [-0.002708, 0.002708], range ~[-5.7136e-24, 5.7110e-24]:
  * |exp(x) - p(x)| < 2**-77.2
- * (0.002708 is ln2/(2*NUM) rounded up a little).
+ * (0.002708 is ln2/(2*INTERVALS) rounded up a little).
  */
 P2 =  0.5,
 P3 =  1.6666666666666119e-1,		/*  0x15555555555490.0p-55 */
@@ -84,16 +84,16 @@ P5 =  8.3333354987869413e-3,		/*  0x1111
 P6 =  1.3888891738560272e-3;		/*  0x16c16c651633ae.0p-62 */
 
 /*
- * 2^(i/NUM) for i in [0,NUM] is represented by two values where the
- * first 47 (?!) bits of the significand is stored in hi and the next 53
+ * 2^(i/INTERVALS) for i in [0,INTERVALS] is represented by two values where
+ * the first 47 (?!) bits of the significand is stored in hi and the next 53
  * bits are in lo.
  */
-#define	NUM		128
+#define	INTERVALS		128
 
 static const struct {
 	double	hi;
 	double	lo;
-} s[NUM] __aligned(16) = {
+} s[INTERVALS] __aligned(16) = {
 	0x1p+0, 0x0p+0,
 	0x1.0163da9fb330p+0, 0x1.ab6c25335719bp-47,
 	0x1.02c9a3e77804p+0, 0x1.07737be56527cp-47,
@@ -265,8 +265,8 @@ expl(long double x)
 #else
 	n  = (int)fn;
 #endif
-	n2 = (unsigned)n % NUM;		/* Tang's j. */
-	k = (n - n2) / NUM;
+	n2 = (unsigned)n % INTERVALS;		/* Tang's j. */
+	k = (n - n2) / INTERVALS;
 	r1 = x - fn * L1;
 	r2 = -fn * L2;