about summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc32/fpu/s_llround.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/powerpc/powerpc32/fpu/s_llround.c')
-rw-r--r--sysdeps/powerpc/powerpc32/fpu/s_llround.c40
1 files changed, 39 insertions, 1 deletions
diff --git a/sysdeps/powerpc/powerpc32/fpu/s_llround.c b/sysdeps/powerpc/powerpc32/fpu/s_llround.c
index 85514a1d3f..bdee74b13c 100644
--- a/sysdeps/powerpc/powerpc32/fpu/s_llround.c
+++ b/sysdeps/powerpc/powerpc32/fpu/s_llround.c
@@ -16,8 +16,11 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <limits.h>
 #include <math.h>
 #include <math_ldbl_opt.h>
+#include <math_private.h>
+#include <stdint.h>
 
 /* Round to the nearest integer, with values exactly on a 0.5 boundary
    rounded away from zero, regardless of the current rounding mode.
@@ -27,7 +30,42 @@
 long long int
 __llround (double x)
 {
-  long long xr = (long long) x;
+  long long xr;
+  if (HAVE_PPC_FCTIDZ)
+    xr = (long long) x;
+  else
+    {
+      /* Avoid incorrect exceptions from libgcc conversions (as of GCC
+	 5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>.  */
+      if (fabs (x) < 0x1p31)
+	xr = (long long int) (long int) x;
+      else
+	{
+	  uint64_t i0;
+	  EXTRACT_WORDS64 (i0, x);
+	  int exponent = ((i0 >> 52) & 0x7ff) - 0x3ff;
+	  if (exponent < 63)
+	    {
+	      unsigned long long int mant
+		= (i0 & ((1ULL << 52) - 1)) | (1ULL << 52);
+	      if (exponent < 52)
+		/* llround is not required to raise "inexact".  */
+		mant >>= 52 - exponent;
+	      else
+		mant <<= exponent - 52;
+	      xr = (long long int) ((i0 & (1ULL << 63)) != 0 ? -mant : mant);
+	    }
+	  else if (x == (double) LLONG_MIN)
+	    xr = LLONG_MIN;
+	  else
+	    xr = (long long int) (long int) x << 32;
+	}
+    }
+  /* Avoid spurious "inexact" converting LLONG_MAX to double, and from
+     subtraction when the result is out of range, by returning early
+     for arguments large enough that no rounding is needed.  */
+  if (!(fabs (x) < 0x1p52))
+    return xr;
   double xrf = (double) xr;
 
   if (x >= 0.0)