Target FP: Add string routines to target-float.{c,h}

This adds target_float_to_string and target_float_from_string,
which dispatch to the corresponding floatformat_ or decimal_ routines.

Existing users of those routines are changed to use the new
target-float routines instead (most of those places already handle
both binary and decimal FP).

In addition, two other places are changes to use target_float_from_string:

- define_symbol in stabsread.c, when parsing a floating-point literal
  from stabs debug info

- gdbarch-selftest.c when initializing a target format values (to
  eliminate use of DOUBLEST there).

gdb/ChangeLog:
2017-11-06  Ulrich Weigand  <uweigand@de.ibm.com>

	* target-float.c (target_float_to_string): New function.
	(target_float_from_string): New function.
	* target-float.h (target_float_to_string): Add prototype.
	(target_float_from_string): Add prototype.

	* valprint.c: Include "target-float.h".  Do not include
	"doublest.h" and "dfp.h".
	(print_floating): Use target_float_to_string.
	* printcmd.c: Include "target-float.h".  Do not include "dfp.h".
	(printf_floating): Use target_float_to_string.
	* i387-tdep.c: Include "target-float.h".  Do not include "doublest.h".
	(print_i387_value): Use target_float_to_string.
	* mips-tdep.c: Include "target-float.h".
	(mips_print_fp_register): Use target_float_to_string.
	* sh64-tdep.c: Include "target-float.h".
	(sh64_do_fp_register): Use target_float_to_string.

	* parse.c: Include "target-float.h".  Do not include
	"doublest.h" and "dfp.h".
	(parse_float): Use target_float_from_string.
	* stabsread.c: Include "target-float.h".  Do not include "doublest.h".
	(define_symbol): Use target_float_from_string.
	* gdbarch-selftests.c: Include "target-float.h".
	(register_to_value_test): Use target_float_from_string.

1 files changed, 3 insertions, 8 deletions

diff --git a/gdb/printcmd.c b/gdb/printcmd.c
index 4323475..017c7be 100644
--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -38,7 +38,7 @@
 #include "ui-out.h"
 #include "block.h"
 #include "disasm.h"
-#include "dfp.h"
+#include "target-float.h"
 #include "observer.h"
 #include "solist.h"
 #include "parser-defs.h"
@@ -2360,13 +2360,8 @@ printf_floating (struct ui_file *stream, const char *format,
   value = value_cast (fmt_type, value);
 
   /* Convert the value to a string and print it.  */
-  std::string str;
-  if (TYPE_CODE (fmt_type) == TYPE_CODE_FLT)
-    str = floatformat_to_string (floatformat_from_type (fmt_type),
-				 value_contents (value), format);
-  else
-    str = decimal_to_string (value_contents (value),
-			     TYPE_LENGTH (fmt_type), byte_order, format);
+  std::string str
+    = target_float_to_string (value_contents (value), fmt_type, format);
   fputs_filtered (str.c_str (), stream);
 }