Re: [RFA/mips] Fix crash trying to print long double float

Joel Brobecker
2004-08-09T05:46:26Z

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> >Tested on mips-irix. OK to apply?
>
> Yes, with these tweaks, commit:

Thanks. Here is what I just checked in:

2004-08-08 Joel Brobecker <brobecker@gnat.com>

* mips-tdep.c: Include "floatformat.h".
(n32n64_floatformat_always_valid): New function.
(floatformat_n32n64_long_double_big): New constant.
(mips_gdbarch_init): Set size and format of long double
for N32 and N64 ABIs.
* Makefile.in (mips-tdep.o): Update dependencies.

--
Joel

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Index: mips-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/mips-tdep.c,v
retrieving revision 1.309
diff -u -p -r1.309 mips-tdep.c
--- mips-tdep.c 3 Aug 2004 01:12:43 -0000 1.309
+++ mips-tdep.c 8 Aug 2004 17:26:15 -0000
@@ -54,6 +54,7 @@
#include "frame-base.h"
#include "trad-frame.h"
#include "infcall.h"
+#include "floatformat.h"

static const struct objfile_data *mips_pdr_data;

@@ -149,6 +150,32 @@ struct gdbarch_tdep
const char **mips_processor_reg_names;
};

+static int
+n32n64_floatformat_always_valid (const struct floatformat *fmt,
+ const char *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_ieee_double_big",
+ n32n64_floatformat_always_valid
+};
+
const struct mips_regnum *
mips_regnum (struct gdbarch *gdbarch)
{
@@ -6323,6 +6350,9 @@ mips_gdbarch_init (struct gdbarch_info i
set_gdbarch_long_bit (gdbarch, 32);
set_gdbarch_ptr_bit (gdbarch, 32);
set_gdbarch_long_long_bit (gdbarch, 64);
+ set_gdbarch_long_double_bit (gdbarch, 128);
+ set_gdbarch_long_double_format (gdbarch,
+ &floatformat_n32n64_long_double_big);
break;
case MIPS_ABI_N64:
set_gdbarch_push_dummy_call (gdbarch, mips_n32n64_push_dummy_call);
@@ -6333,6 +6363,9 @@ mips_gdbarch_init (struct gdbarch_info i
set_gdbarch_long_bit (gdbarch, 64);
set_gdbarch_ptr_bit (gdbarch, 64);
set_gdbarch_long_long_bit (gdbarch, 64);
+ set_gdbarch_long_double_bit (gdbarch, 128);
+ set_gdbarch_long_double_format (gdbarch,
+ &floatformat_n32n64_long_double_big);
break;
default:
internal_error (__FILE__, __LINE__, "unknown ABI in switch");
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.606
diff -u -p -r1.606 Makefile.in
--- Makefile.in 6 Aug 2004 19:14:44 -0000 1.606
+++ Makefile.in 8 Aug 2004 17:26:16 -0000
@@ -2206,7 +2206,8 @@ mips-tdep.o: mips-tdep.c $(defs_h) $(gdb
$(target_h) $(arch_utils_h) $(regcache_h) $(osabi_h) $(mips_tdep_h) \
$(block_h) $(reggroups_h) $(opcode_mips_h) $(elf_mips_h) \
$(elf_bfd_h) $(symcat_h) $(sim_regno_h) $(dis_asm_h) \
- $(frame_unwind_h) $(frame_base_h) $(trad_frame_h) $(infcall_h)
+ $(frame_unwind_h) $(frame_base_h) $(trad_frame_h) $(infcall_h) \
+ $(floatformat_h)
mipsv4-nat.o: mipsv4-nat.c $(defs_h) $(inferior_h) $(gdbcore_h) $(target_h) \
$(regcache_h) $(gregset_h)
mn10300-tdep.o: mn10300-tdep.c $(defs_h) $(frame_h) $(inferior_h) \