* i386-tdep.c (i386_extract_return_value): "Fix" comment.

(i386_store_return_value): Frob FPU status and tag word to make
sure the return value is the only value on the FPU stack.
This commit is contained in:
Mark Kettenis 2001-07-11 08:43:41 +00:00
parent f8d13125bf
commit ccb945b81e
2 changed files with 18 additions and 1 deletions

View file

@ -1,5 +1,9 @@
2001-07-11 Mark Kettenis <kettenis@gnu.org>
* i386-tdep.c (i386_extract_return_value): "Fix" comment.
(i386_store_return_value): Frob FPU status and tag word to make
sure the return value is the only value on the FPU stack.
* config/tm-linux.h: Do not include <signal.h>. Instead provide
reasonable defaults for REALTIME_LO and REALTIME_HI if they're not
already defined.

View file

@ -803,7 +803,8 @@ i386_extract_return_value (struct type *type, char *regbuf, char *valbuf)
return;
}
/* Floating-point return values can be found in %st(0). */
/* Floating-point return values can be found in %st(0).
FIXME: Does %st(0) always correspond to FP0? */
if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT
&& TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext)
{
@ -861,6 +862,8 @@ i386_store_return_value (struct type *type, char *valbuf)
if (TYPE_CODE (type) == TYPE_CODE_FLT)
{
unsigned int fstat;
if (NUM_FREGS == 0)
{
warning ("Cannot set floating-point return value.");
@ -889,6 +892,16 @@ i386_store_return_value (struct type *type, char *valbuf)
write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf,
FPU_REG_RAW_SIZE);
}
/* Set the top of the floating point register stack to 7. That
makes sure that FP0 (which we set above) is indeed %st(0).
FIXME: Perhaps we should completely reset the status word? */
fstat = read_register (FSTAT_REGNUM);
fstat |= (7 << 11);
write_register (FSTAT_REGNUM, fstat);
/* Mark %st(1) through %st(7) as empty. */
write_register (FTAG_REGNUM, 0x3fff);
}
else
{