* real.c (real_maxval): New function to return the largest finite

	value representable in a given mode (i.e. FLT_MAX and DBL_MAX).
	* real.h (real_maxval): Prototype here.
	* fold-const.c (fold_inf_compare): Transform comparisons against
	+-Infinity into comparisons against DBL_MAX (or equivalent).

	* gcc.c-torture/execute/ieee/inf-2.c: New test case.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@67112 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 27 insertions, 0 deletions

diff --git a/gcc/real.c b/gcc/real.c
index 16cd02acb7f..4a4b04012ce 100644
--- a/gcc/real.c
+++ b/gcc/real.c
@@ -2280,6 +2280,33 @@ real_nan (r, str, quiet, mode)
   return true;
 }
 
+/* Fills R with the largest finite value representable in mode MODE.
+   If SIGN is non-zero, R is set to the most negative finite value.  */
+
+void
+real_maxval (r, sign, mode)
+     REAL_VALUE_TYPE *r;
+     int sign;
+     enum machine_mode mode;
+{
+  const struct real_format *fmt;
+  int np2;
+
+  fmt = real_format_for_mode[mode - QFmode];
+  if (fmt == NULL)
+    abort ();
+
+  r->class = rvc_normal;
+  r->sign = sign;
+  r->signalling = 0;
+  r->canonical = 0;
+  r->exp = fmt->emax * fmt->log2_b;
+
+  np2 = SIGNIFICAND_BITS - fmt->p * fmt->log2_b;
+  memset (r->sig, -1, SIGSZ * sizeof (unsigned long));
+  clear_significand_below (r, np2);
+}
+
 /* Fills R with 2**N.  */
 
 void