as is: mips-tdep long doubles...

[Joel Brobecker <brobecker at adacore dot com>]

Hello,

Attached is a patch that might be interesting to people who are still
running GDB on mips-irix... As the FIXME suggests, it is not perfect,
but it helps. Since I will probably never find the time to improve it,
I thought I'd just publish the patch here, in case someone could use it
too.

-- 
Joel

diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index c7684f8..89afeb8 100644
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -187,6 +187,38 @@ static unsigned int mips_debug = 0;
 struct target_desc *mips_tdesc_gp32;
 struct target_desc *mips_tdesc_gp64;
 
+static int
+n32n64_floatformat_always_valid (const struct floatformat *fmt,
+                                 const void *from)
+{
+  return 1;
+}
+
+/* FIXME: brobecker/2004-08-08: Long Double values are 128 bit long.
+   They are implemented as a pair of 64bit doubles where the high
+   part holds the result of the operation rounded to double, and
+   the low double holds the difference between the exact result and
+   the rounded result.  So "high" + "low" contains the result with
+   added precision.  Unfortunately, the floatformat structure used
+   by GDB is not powerful enough to describe this format.  As a temporary
+   measure, we define a 128bit floatformat that only uses the high part.
+   We lose a bit of precision but that's probably the best we can do
+   for now with the current infrastructure.  */
+
+static const struct floatformat floatformat_n32n64_long_double_big =
+{
+  floatformat_big, 128, 0, 1, 11, 1023, 2047, 12, 52,
+  floatformat_intbit_no,
+  "floatformat_n32n64_long_double_big",
+  n32n64_floatformat_always_valid
+};
+
+static const struct floatformat *floatformats_n32n64_long[BFD_ENDIAN_UNKNOWN] =
+{
+  &floatformat_n32n64_long_double_big,
+  &floatformat_n32n64_long_double_big
+};
+
 const struct mips_regnum *
 mips_regnum (struct gdbarch *gdbarch)
 {