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Patch for new i386 `info float' command
- To: gdb-patches at sourceware dot cygnus dot com
- Subject: Patch for new i386 `info float' command
- From: Mark Kettenis <kettenis at wins dot uva dot nl>
- Date: Sat, 13 Nov 1999 19:17:21 +0100 (CET)
Here is a patch that implements the new generic i386 `info float'
command. The new i387-tdep.c is a bit of a mess since it still
contains code that used by some of the old target specific `info
float' implementation and the Linux `long double' kludges. These bits
of code should be removed eventually and I added some comments saying
so.
The new `info float' command uses the *_filtered functions as
suggested by Andrew Cagney. The way the floating point values are
printed means that on some hosts there is a partial precision loss. I
think this is OK since full information is still available (as
hexadecimal output) and even partial information can be useful.
Mark
1999-11-13 Mark Kettenis <kettenis@gnu.org>
* config/i386/tm-i386.h (FLOAT_INFO): New define.
* i387-tdep.c (print_i387_value, print_i387_ext,
print_i387_status_word, print_i387_control_word, i387_float_info):
New functions, used to implement generic `info float' command.
Index: config/i386/tm-i386.h
===================================================================
RCS file: /var/cvsroot/gdb/gdb/config/i386/tm-i386.h,v
retrieving revision 1.1.1.8
diff -u -r1.1.1.8 tm-i386.h
--- config/i386/tm-i386.h 1999/11/13 14:31:07 1.1.1.8
+++ config/i386/tm-i386.h 1999/11/13 17:30:39
@@ -259,6 +259,13 @@
double_to_i387((char *)&val, (TO)); \
}
+/* Print out the i387 floating point state. */
+#ifdef HAVE_I387_REGS
+extern void i387_float_info (void);
+#define FLOAT_INFO { i387_float_info (); }
+#endif
+
+
/* Store the address of the place in which to copy the structure the
subroutine will return. This is called from call_function. */
Index: i387-tdep.c
===================================================================
RCS file: /var/cvsroot/gdb/gdb/i387-tdep.c,v
retrieving revision 1.1.1.4
diff -u -r1.1.1.4 i387-tdep.c
--- i387-tdep.c 1999/10/02 19:51:09 1.1.1.4
+++ i387-tdep.c 1999/11/13 17:27:21
@@ -1,5 +1,5 @@
/* Intel 387 floating point stuff.
- Copyright (C) 1988, 1989, 1991, 1998 Free Software Foundation, Inc.
+ Copyright (C) 1988, 1989, 1991, 1998, 1999 Free Software Foundation, Inc.
This file is part of GDB.
@@ -26,14 +26,12 @@
#include "gdbcore.h"
#include "floatformat.h"
-void i387_to_double PARAMS ((char *, char *));
-void double_to_i387 PARAMS ((char *, char *));
-static void print_387_control_bits PARAMS ((unsigned int control));
-static void print_387_status_bits PARAMS ((unsigned int status));
+/* FIXME: Eliminate the next two functions when we have the time to
+ change all the callers. */
-/* FIXME: Eliminate these routines when we have the time to change all
- the callers. */
+void i387_to_double PARAMS ((char *from, char *to));
+void double_to_i387 PARAMS ((char *from, char *to));
void
i387_to_double (from, to)
@@ -51,6 +49,16 @@
floatformat_from_double (&floatformat_i387_ext, (double *) from, to);
}
+
+/* FIXME: The functions on this page are used by the old `info float'
+ implementations that a few of the i386 targets provide. These
+ functions should be removed if all of these have been converted to
+ use the generic implementation based on the new register file
+ layout. */
+
+static void print_387_control_bits PARAMS ((unsigned int control));
+static void print_387_status_bits PARAMS ((unsigned int status));
+
static void
print_387_control_bits (control)
unsigned int control;
@@ -149,6 +157,243 @@
puts_unfiltered ("\n");
}
+
+/* Implement the `info float' layout based on the register definitions
+ in `tm-i386.h'. */
+
+/* Print the floating point number specified by RAW. */
+static void
+print_i387_value (char *raw)
+{
+ DOUBLEST value;
+
+ floatformat_to_doublest (&floatformat_i387_ext, raw, &value);
+
+ /* We try to print 19 digits. The last digit may or may not contain
+ garbage, but we'd better print one too many. We need enough room
+ to print the value, 1 position for the sign, 1 for the decimal
+ point, 19 for the digits and 6 for the exponent adds up to 27. */
+#ifdef PRINTF_HAS_LONG_DOUBLE
+ printf_filtered (" %-+27.19Lg", (long double) value);
+#else
+ printf_filtered (" %-+27.19g", (double) value);
+#endif
+}
+
+/* Print the classification for the register contents RAW. */
+static void
+print_i387_ext (unsigned char *raw)
+{
+ int sign;
+ int integer;
+ unsigned int exponent;
+ unsigned long fraction[2];
+
+ sign = raw[9] & 0x80;
+ integer = raw[7] & 0x80;
+ exponent = (((raw[9] & 0x7f) << 8) | raw[8]);
+ fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]);
+ fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16)
+ | (raw[5] << 8) | raw[4]);
+
+ if (exponent == 0x7fff && integer)
+ {
+ if (fraction[0] == 0x00000000 && fraction[1] == 0x00000000)
+ /* Infinity. */
+ printf_filtered (" %cInf", (sign ? '-' : '+'));
+ else if (sign && fraction[0] == 0x00000000 && fraction[1] == 0x40000000)
+ /* Real Indefinite (QNaN). */
+ puts_unfiltered (" Real Indefinite (QNaN)");
+ else if (fraction[1] & 0x40000000)
+ /* QNaN. */
+ puts_filtered (" QNaN");
+ else
+ /* SNaN. */
+ puts_filtered (" SNaN");
+ }
+ else if (exponent < 0x7fff && exponent > 0x0000 && integer)
+ /* Normal. */
+ print_i387_value (raw);
+ else if (exponent == 0x0000)
+ {
+ /* Denormal or zero. */
+ print_i387_value (raw);
+
+ if (integer)
+ /* Pseudo-denormal. */
+ puts_filtered (" Pseudo-denormal");
+ else if (fraction[0] || fraction[1])
+ /* Denormal. */
+ puts_filtered (" Denormal");
+ }
+ else
+ /* Unsupported. */
+ puts_filtered (" Unsupported");
+}
+
+/* Print the status word STATUS. */
+static void
+print_i387_status_word (unsigned int status)
+{
+ printf_filtered ("Status Word: %s",
+ local_hex_string_custom (status, "04"));
+ puts_filtered (" ");
+ printf_filtered (" %s", (status & 0x0001) ? "IE" : " ");
+ printf_filtered (" %s", (status & 0x0002) ? "DE" : " ");
+ printf_filtered (" %s", (status & 0x0004) ? "ZE" : " ");
+ printf_filtered (" %s", (status & 0x0008) ? "OE" : " ");
+ printf_filtered (" %s", (status & 0x0010) ? "UE" : " ");
+ printf_filtered (" %s", (status & 0x0020) ? "PE" : " ");
+ puts_filtered (" ");
+ printf_filtered (" %s", (status & 0x0080) ? "ES" : " ");
+ puts_filtered (" ");
+ printf_filtered (" %s", (status & 0x0080) ? "SF" : " ");
+ puts_filtered (" ");
+ printf_filtered (" %s", (status & 0x0100) ? "C0" : " ");
+ printf_filtered (" %s", (status & 0x0200) ? "C1" : " ");
+ printf_filtered (" %s", (status & 0x0400) ? "C2" : " ");
+ printf_filtered (" %s", (status & 0x4000) ? "C3" : " ");
+
+ puts_filtered ("\n");
+
+ printf_filtered (" TOP: %d\n", ((status >> 11) & 7));
+}
+
+/* Print the control word CONTROL. */
+static void
+print_i387_control_word (unsigned int control)
+{
+ printf_filtered ("Control Word: %s",
+ local_hex_string_custom (control, "04"));
+ puts_filtered (" ");
+ printf_filtered (" %s", (control & 0x0001) ? "IM" : " ");
+ printf_filtered (" %s", (control & 0x0002) ? "DM" : " ");
+ printf_filtered (" %s", (control & 0x0004) ? "ZM" : " ");
+ printf_filtered (" %s", (control & 0x0008) ? "OM" : " ");
+ printf_filtered (" %s", (control & 0x0010) ? "UM" : " ");
+ printf_filtered (" %s", (control & 0x0020) ? "PM" : " ");
+
+ puts_filtered ("\n");
+
+ puts_filtered (" PC: ");
+ switch ((control >> 8) & 3)
+ {
+ case 0:
+ puts_filtered ("Single Precision (24-bits)\n");
+ break;
+ case 1:
+ puts_filtered ("Reserved\n");
+ break;
+ case 2:
+ puts_filtered ("Double Precision (53-bits)\n");
+ break;
+ case 3:
+ puts_filtered ("Extended Precision (64-bits)\n");
+ break;
+ }
+
+ puts_filtered (" RC: ");
+ switch ((control >> 10) & 3)
+ {
+ case 0:
+ puts_filtered ("Round to nearest\n");
+ break;
+ case 1:
+ puts_filtered ("Round down\n");
+ break;
+ case 2:
+ puts_filtered ("Round up\n");
+ break;
+ case 3:
+ puts_filtered ("Round toward zero\n");
+ break;
+ }
+}
+
+/* Print out the i387 floating poin state. */
+void
+i387_float_info (void)
+{
+ unsigned int fctrl;
+ unsigned int fstat;
+ unsigned int ftag;
+ unsigned int fiseg;
+ unsigned int fioff;
+ unsigned int foseg;
+ unsigned int fooff;
+ unsigned int fop;
+ int fpreg;
+ int top;
+
+ fctrl = read_register (FCTRL_REGNUM);
+ fstat = read_register (FSTAT_REGNUM);
+ ftag = read_register (FTAG_REGNUM);
+ fiseg = read_register (FCS_REGNUM);
+ fioff = read_register (FCOFF_REGNUM);
+ foseg = read_register (FDS_REGNUM);
+ fooff = read_register (FDOFF_REGNUM);
+ fop = read_register (FOP_REGNUM);
+
+ top = ((fstat >> 11) & 7);
+
+ for (fpreg = 7; fpreg >= 0; fpreg--)
+ {
+ unsigned char raw[FPU_REG_RAW_SIZE];
+ int tag = (ftag >> (fpreg * 2)) & 3;
+ int i;
+
+ printf_filtered ("%sR%d: ", fpreg == top ? "=>" : " ", fpreg);
+
+ switch (tag)
+ {
+ case 0:
+ puts_filtered ("Valid ");
+ break;
+ case 1:
+ puts_filtered ("Zero ");
+ break;
+ case 2:
+ puts_filtered ("Special ");
+ break;
+ case 3:
+ puts_filtered ("Empty ");
+ break;
+ }
+
+ read_register_gen ((fpreg + 8 - top) % 8 + FP0_REGNUM, raw);
+
+ puts_filtered ("0x");
+ for (i = 9; i >= 0; i--)
+ printf_filtered ("%02x", raw[i]);
+
+ if (tag != 3)
+ print_i387_ext (raw);
+
+ puts_filtered ("\n");
+ }
+
+ puts_filtered ("\n");
+
+ print_i387_status_word (fstat);
+ print_i387_control_word (fctrl);
+ printf_filtered ("Tag Word: %s\n",
+ local_hex_string_custom (ftag, "04"));
+ printf_filtered ("Instruction Pointer: %s:",
+ local_hex_string_custom (fiseg, "02"));
+ printf_filtered ("%s\n", local_hex_string_custom (fioff, "08"));
+ printf_filtered ("Operand Pointer: %s:",
+ local_hex_string_custom (foseg, "02"));
+ printf_filtered ("%s\n", local_hex_string_custom (fooff, "08"));
+ printf_filtered ("Opcode: %s\n",
+ local_hex_string_custom (fop ? (fop | 0xd800) : 0, "04"));
+}
+
+
+/* FIXME: The functions on this page are used to provide `long double'
+ support for Linux. However, the approach does not seem to be the
+ right one, and we are planning to solve this in a way that should
+ work for all i386 targets. These functions will disappear in the
+ near future, so please don't use them. */
#ifdef LD_I387
int
i387_extract_floating (PTR addr, int len, DOUBLEST *dretptr)