------- Comment #4 from jakub at gcc dot gnu dot org 2008-04-23 13:29 -------
I've instead regtested:
--- gcc/config/i386/i386.c.jj 2008-04-01 13:34:27.000000000 +0200
+++ gcc/config/i386/i386.c 2008-04-23 13:38:14.000000000 +0200
@@ -3501,7 +3501,7 @@ init_cumulative_args (CUMULATIVE_ARGS *c
{
/* If there are variable arguments, then we won't pass anything
in registers in 32-bit mode. */
- if (cum->maybe_vaarg)
+ if (stdarg_p (fntype))
{
cum->nregs = 0;
cum->sse_nregs = 0;
patch (on i686 only, as this is !TARGET_64BIT hunk of code).
IMHO it best matches what 4.2 and earlier did. Here is the 4.2 code:
cum->maybe_vaarg = false;
...
/* Determine if this function has variable arguments. This is
indicated by the last argument being 'void_type_mode' if there
are no variable arguments. If there are variable arguments, then
we won't pass anything in registers in 32-bit mode. */
if (cum->nregs || cum->mmx_nregs || cum->sse_nregs)
{
for (param = (fntype) ? TYPE_ARG_TYPES (fntype) : 0;
param != 0; param = next_param)
{
next_param = TREE_CHAIN (param);
if (next_param == 0 && TREE_VALUE (param) != void_type_node)
{
if (!TARGET_64BIT)
{
cum->nregs = 0;
cum->sse_nregs = 0;
cum->mmx_nregs = 0;
cum->warn_sse = 0;
cum->warn_mmx = 0;
cum->fastcall = 0;
cum->float_in_sse = 0;
}
cum->maybe_vaarg = true;
}
}
}
if ((!fntype && !libname)
|| (fntype && !TYPE_ARG_TYPES (fntype)))
cum->maybe_vaarg = true;
The param/next_param testing IMHO is stdarg_p test, so cum->nregs etc. are
cleared only if !TARGET_64BIT && stdarg_p (fntype). maybe_vaarg is set if
stdarg_p (fntype), or for fntype && !prototype_p (fntype), or for !fntype &&
!libname.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36015
