[gcc r13-2808] frange: dump hex values when dumping FP numbers.

[Aldy Hernandez <aldyh@gcc.gnu.org>]

https://gcc.gnu.org/g:0706262498bc5d206330c08414df0c780a0c3141

commit r13-2808-g0706262498bc5d206330c08414df0c780a0c3141
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Thu Sep 22 18:07:03 2022 +0200

    frange: dump hex values when dumping FP numbers.
    
    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?
    
    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.

Diff:
---
 gcc/value-range-pretty-print.cc | 19 +++++++++++++++----
 gcc/value-range-pretty-print.h  |  1 +
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/gcc/value-range-pretty-print.cc b/gcc/value-range-pretty-print.cc
index eb7442229ba..8cbe97b76fd 100644
--- a/gcc/value-range-pretty-print.cc
+++ b/gcc/value-range-pretty-print.cc
@@ -117,6 +117,19 @@ 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[100];
+  real_to_decimal_for_mode (s, &r, sizeof (s), 0, 1, TYPE_MODE (type));
+  pp_string (pp, s);
+  if (!DECIMAL_FLOAT_TYPE_P (type))
+    {
+      real_to_hexadecimal (s, &r, sizeof (s), 0, 1);
+      pp_printf (pp, " (%s)", s);
+    }
+}
+
 // Print an frange.
 
 void
@@ -141,11 +154,9 @@ 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;
 };