[PATCH] frange: dump hex values when dumping FP numbers.

[Aldy Hernandez <aldyh@redhat.com>]

It has been suggested that if we start bumping numbers by an ULP when
calculating open ranges (for example the numbers less than 3.0) that
dumping these will become increasingly harder to read, and instead we
should opt for the hex representation.  I still find the floating
point representation easier to read for most numbers, but perhaps we
could have both?

With this patch this is the representation for [15.0, 20.0]:

     [frange] float [1.5e+1 (0x0.fp+4), 2.0e+1 (0x0.ap+5)]

Would you find this useful, or should we stick to the hex
representation only (or something altogether different)?

Tested on x86-64 Linux.

gcc/ChangeLog:

	* value-range-pretty-print.cc (vrange_printer::print_real_value): New.
	(vrange_printer::visit): Call print_real_value.
	* value-range-pretty-print.h: New print_real_value.
---
 gcc/value-range-pretty-print.cc | 16 ++++++++++++----
 gcc/value-range-pretty-print.h  |  1 +
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/gcc/value-range-pretty-print.cc b/gcc/value-range-pretty-print.cc
index eb7442229ba..51be037c254 100644
--- a/gcc/value-range-pretty-print.cc
+++ b/gcc/value-range-pretty-print.cc
@@ -117,6 +117,16 @@ vrange_printer::print_irange_bitmasks (const irange &r) const
   pp_string (pp, buf);
 }
 
+void
+vrange_printer::print_real_value (tree type, const REAL_VALUE_TYPE &r) const
+{
+  char s[60];
+  tree t = build_real (type, r);
+  dump_generic_node (pp, t, 0, TDF_NONE, false);
+  real_to_hexadecimal (s, &r, sizeof (s), 0, 1);
+  pp_printf (pp, " (%s)", s);
+}
+
 // Print an frange.
 
 void
@@ -141,11 +151,9 @@ vrange_printer::visit (const frange &r) const
   bool has_endpoints = !r.known_isnan ();
   if (has_endpoints)
     {
-      dump_generic_node (pp,
-			 build_real (type, r.lower_bound ()), 0, TDF_NONE, false);
+      print_real_value (type, r.lower_bound ());
       pp_string (pp, ", ");
-      dump_generic_node (pp,
-			 build_real (type, r.upper_bound ()), 0, TDF_NONE, false);
+      print_real_value (type, r.upper_bound ());
     }
   pp_character (pp, ']');
   print_frange_nan (r);
diff --git a/gcc/value-range-pretty-print.h b/gcc/value-range-pretty-print.h
index 20c26598fe7..a9ae5a7b4cc 100644
--- a/gcc/value-range-pretty-print.h
+++ b/gcc/value-range-pretty-print.h
@@ -32,6 +32,7 @@ private:
   void print_irange_bound (const wide_int &w, tree type) const;
   void print_irange_bitmasks (const irange &) const;
   void print_frange_nan (const frange &) const;
+  void print_real_value (tree type, const REAL_VALUE_TYPE &r) const;
 
   pretty_printer *pp;
 };
-- 
2.37.1