__builtin_apply does not pass args to called function correctly

[GoogleCodeExporter]

probably need to do some magic to enforce SX calling convention.

affected testcases:

gcc.dg/builtin-apply2.c
gcc.dg/builtin-apply3.c
gcc.dg/builtin-apply4.c
gcc.dg/builtin-return-1.c

Original issue reported on code.google.com by [email protected] on 30 Jan 2009 at 10:04

[GoogleCodeExporter]

also, this one is probably the root cause of failing 
gcc.dg/compat/struct-by-value-22
testcase.

Original comment by [email protected] on 5 Feb 2009 at 3:15

• Added labels: Priority-Critical
• Removed labels: Priority-Medium

[GoogleCodeExporter]

struct-by-value-22 is a whole other problem.

Original comment by [email protected] on 6 Feb 2009 at 11:16

[GoogleCodeExporter]

__builtin_apply() is seriously broken, and probably can not be fixed without 
patching
the the target-independent sources(gcc/builtins.c:expand_builtin_apply()).

perhaps wait for port to 4.4/4.5?

Original comment by [email protected] on 6 Feb 2009 at 4:24

• Added labels: Priority-Low
• Removed labels: Priority-Critical

[GoogleCodeExporter]

the main problem with __builtin_apply() is that is subtracts the size of the
arguments passed to it from arg pointer:

#ifndef STACK_GROWS_DOWNWARD
  incoming_args = expand_simple_binop (Pmode, MINUS, incoming_args, argsize,
                       incoming_args, 0, OPTAB_LIB_WIDEN);
#endif

arg pointer, however, points to the bottom of the arguments already. similar 
occurs
when calculating dest address for outgoing arguments, a few lines onward.

Original comment by [email protected] on 9 Feb 2009 at 3:09