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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/powerpc
parentd81dcb356909937b0c8e9c69ff0be27f51aaa07a (diff)
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Optimize handling of denormals in logb/logbf/logbl
Diffstat (limited to 'sysdeps/powerpc')
-rw-r--r--sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c13
-rw-r--r--sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c8
2 files changed, 10 insertions, 11 deletions
diff --git a/sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c b/sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c
index fba4822900..87176c34c9 100644
--- a/sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c
+++ b/sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c
@@ -55,13 +55,14 @@ __logb (double x)
       /* POSIX specifies that denormal numbers are treated as
          though they were normalized.  */
       int32_t lx, ix;
-      int m1, m2, ma;
+      int ma;
 
-      EXTRACT_WORDS (ix , lx, x);
-      m1 = (ix == 0) ? 0 : __builtin_clz (ix);
-      m2 = (lx == 0) ? 0 : __builtin_clz (lx);
-      ma = (m1 == 0) ? m2 + 32 : m1;
-      return -1022.0 + (double)(11 - ma);
+      EXTRACT_WORDS (ix, lx, x);
+      if (ix == 0)
+	ma = __builtin_clz (lx) + 32;
+      else
+	ma = __builtin_clz (ix);
+      return (double) (-1023 - (ma - 12));
     }
   /* Test to avoid logb_downward (0.0) == -0.0.  */
   return ret == -0.0 ? 0.0 : ret;
diff --git a/sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c b/sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c
index 03942ca53d..20c7d4e6e9 100644
--- a/sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c
+++ b/sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c
@@ -56,14 +56,12 @@ __logbl (long double x)
     return (xh * xh);
   else if (__builtin_expect (ret == two10m1, 0))
     {
+      /* POSIX specifies that denormal number is treated as
+         though it were normalized.  */
       int64_t lx, hx;
-      int m1, m2, ma;
 
       GET_LDOUBLE_WORDS64 (hx, lx, x);
-      m1 = (hx == 0) ? 0 : __builtin_clzll (hx);
-      m2 = (lx == 0) ? 0 : __builtin_clzll (lx);
-      ma = (m1 == 0) ? m2 + 64 : m1;
-      return -1022.0 + (double)(11 - ma);
+      return (long double) (-1023 - (__builtin_clzll (hx) - 12));
     }
   /* Test to avoid logb_downward (0.0) == -0.0.  */
   return ret == -0.0 ? 0.0 : ret;