diff options
| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2014-02-17 13:25:24 +0100 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2014-02-17 13:25:24 +0100 |
| commit | 2c5c78425516590e894c9c334182073fcc56a10b (patch) | |
| tree | ec4c8b58ec1d8144936bf8111382a6e7141d55c0 /sys/src/libc/amd64 | |
| parent | 87fcb107ef333f5dce7618e0f4c73d69ebc75eb5 (diff) | |
prof: properly save and restore RARG for amd64
amd64 passes first argument in RARG (BP) register
which has the be preserved duing _profin() and
_profout() calls. to handle this we introduce
_saveret() and _savearg(). _saveret() returns
AX, _savearg() returns RARG (BP). for archs other
and amd64, _saveret() and _savearg() are the
same function, doing nothing.
restoing works with dummy function:
uintptr
_restore(uintptr, uintptr ret)
{
return ret;
}
...
ret = _saveret();
arg = _savearg();
...
return _restore(arg, ret);
as we pass arg as the first argument, RARG (BP) is
restored.
Diffstat (limited to 'sys/src/libc/amd64')
| -rw-r--r-- | sys/src/libc/amd64/main9p.s | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/sys/src/libc/amd64/main9p.s b/sys/src/libc/amd64/main9p.s index 353b18088..c1a8fac2b 100644 --- a/sys/src/libc/amd64/main9p.s +++ b/sys/src/libc/amd64/main9p.s @@ -28,9 +28,6 @@ TEXT _savearg(SB), 1, $0 RET TEXT _saveret(SB), 1, $0 - RET - -TEXT _restorearg(SB), 1, $0 RET /* we want RARG in RARG */ TEXT _callpc(SB), 1, $0 |