libm: remove scalbln implementation, it seems to be less correct than scalbn.

 instead, either alias scalbln to scalbn if int == long on this arch, or
 just call scalbn form scalbln.

    text           data     bss     dec     hex filename
-  45297            180       4   45481    b1a9 lib/libm.so
+  44969            180       4   45153    b061 lib/libm.so

1 files changed, 47 insertions, 25 deletions

diff --git a/libm/s_scalbn.c b/libm/s_scalbn.c
index c98ea9d1c..bb14802d8 100644
--- a/libm/s_scalbn.c
+++ b/libm/s_scalbn.c
@@ -11,7 +11,7 @@
 
 /*
  * scalbn (double x, int n)
- * scalbn(x,n) returns x* 2**n  computed by  exponent
+ * scalbn(x,n) returns x* 2**n computed by exponent
  * manipulation rather than by actually performing an
  * exponentiation or a multiplication.
  */
@@ -20,35 +20,57 @@
 #include "math_private.h"
 
 static const double
-two54   =  1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
-twom54  =  5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
+two54  = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
+twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
 huge   = 1.0e+300,
 tiny   = 1.0e-300;
 
 double scalbn(double x, int n)
 {
-	int32_t k,hx,lx;
-	EXTRACT_WORDS(hx,lx,x);
-        k = (hx&0x7ff00000)>>20;		/* extract exponent */
-        if (k==0) {				/* 0 or subnormal x */
-            if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */
-	    x *= two54;
-	    GET_HIGH_WORD(hx,x);
-	    k = ((hx&0x7ff00000)>>20) - 54;
-            if (n< -50000) return tiny*x; 	/*underflow*/
-	    }
-        if (k==0x7ff) return x+x;		/* NaN or Inf */
-        k = k+n;
-        if (k >  0x7fe) return huge*copysign(huge,x); /* overflow  */
-        if (k > 0) 				/* normal result */
-	    {SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20)); return x;}
-        if (k <= -54) {
-            if (n > 50000) 	/* in case integer overflow in n+k */
-		return huge*copysign(huge,x);	/*overflow*/
-	    else return tiny*copysign(tiny,x); 	/*underflow*/
+	int32_t k, hx, lx;
+
+	EXTRACT_WORDS(hx, lx, x);
+	k = (hx & 0x7ff00000) >> 20; /* extract exponent */
+	if (k == 0) { /* 0 or subnormal x */
+		if ((lx | (hx & 0x7fffffff)) == 0)
+			return x; /* +-0 */
+		x *= two54;
+		GET_HIGH_WORD(hx, x);
+		k = ((hx & 0x7ff00000) >> 20) - 54;
+	}
+	if (k == 0x7ff)
+		return x + x; /* NaN or Inf */
+	k = k + n;
+	if (k > 0x7fe)
+		return huge * copysign(huge, x); /* overflow */
+	if (n < -50000)
+		return tiny * copysign(tiny, x); /* underflow */
+	if (k > 0) { /* normal result */
+		SET_HIGH_WORD(x, (hx & 0x800fffff) | (k << 20));
+		return x;
 	}
-        k += 54;				/* subnormal result */
-	SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20));
-        return x*twom54;
+	if (k <= -54) {
+		if (n > 50000) /* in case integer overflow in n+k */
+			return huge * copysign(huge, x); /* overflow */
+		return tiny * copysign(tiny, x); /* underflow */
+	}
+	k += 54; /* subnormal result */
+	SET_HIGH_WORD(x, (hx & 0x800fffff) | (k << 20));
+	return x * twom54;
 }
 libm_hidden_def(scalbn)
+
+#if LONG_MAX == INT_MAX
+/* strong_alias(scalbn, scalbln) - "error: conflicting types for 'scalbln'"
+ * because it tries to declare "typeof(scalbn) scalbln;"
+ * which tries to give "int" parameter to scalbln.
+ * Doing it by hand:
+ */
+__typeof(scalbln) scalbln __attribute__((alias("scalbn")));
+#else
+double scalbln(double x, long n)
+{
+	return scalbn(x, n);
+}
+#endif
+libm_hidden_def(scalbln)