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authorAndreas Schwab <schwab@linux-m68k.org>2012-05-25 11:57:33 +0200
committerAndreas Schwab <schwab@linux-m68k.org>2012-05-26 13:53:22 +0200
commit25dbcb277a9dea5f241c0b888a30b9341310d941 (patch)
tree74c7933f325f44fed6f2f15fd87c59fd4752be37 /sysdeps/ieee754/ldbl-128ibm
parentd81dcb356909937b0c8e9c69ff0be27f51aaa07a (diff)
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Optimize handling of denormals in logb/logbf/logbl
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_logbl.c7
1 files changed, 2 insertions, 5 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_logbl.c b/sysdeps/ieee754/ldbl-128ibm/s_logbl.c
index 678b6cad57..92ce2c1896 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_logbl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_logbl.c
@@ -30,7 +30,7 @@ __logbl (long double x)
 
   GET_LDOUBLE_WORDS64 (hx, lx, x);
   hx &= 0x7fffffffffffffffLL;	/* high |x| */
-  if ((hx | (lx & 0x7fffffffffffffffLL)) == 0)
+  if (hx == 0)
     return -1.0 / fabs (x);
   if (hx >= 0x7ff0000000000000LL)
     return x * x;
@@ -38,10 +38,7 @@ __logbl (long double x)
     {
       /* POSIX specifies that denormal number is treated as
          though it were normalized.  */
-      int m1 = (hx == 0) ? 0 : __builtin_clzll (hx);
-      int m2 = (lx == 0) ? 0 : __builtin_clzll (lx);
-      int ma = (m1 == 0) ? m2 + 64 : m1;
-      return -1022.0 + (long double)(11 - ma);
+      rhx -= __builtin_clzll (hx) - 12;
     }
   return (long double) (rhx - 1023);
 }