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| author | Mark Kettenis <kettenis@gnu.org> | 2001-07-11 08:43:41 +0000 |
|---|---|---|
| committer | Mark Kettenis <kettenis@gnu.org> | 2001-07-11 08:43:41 +0000 |
| commit | ccb945b81ed53beb1b3849800949c409b4585140 (patch) | |
| tree | fb50886f24c76d53af94aa6419e480d44a117182 /gdb/i386-tdep.c | |
| parent | f8d13125bf61d0c1e73dde18ebf581e14a4e62a5 (diff) | |
| download | gdb-ccb945b81ed53beb1b3849800949c409b4585140.zip gdb-ccb945b81ed53beb1b3849800949c409b4585140.tar.gz gdb-ccb945b81ed53beb1b3849800949c409b4585140.tar.bz2 | |
* 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.
Diffstat (limited to 'gdb/i386-tdep.c')
| -rw-r--r-- | gdb/i386-tdep.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c index 0e3e340..108a707 100644 --- a/gdb/i386-tdep.c +++ b/gdb/i386-tdep.c @@ -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 { |