https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66754
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |INVALID
--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> ---
Here is a testcase without -mregparm=N:
[hjl@gnu-tools-1 pr66754]$ cat x.i
extern void abort(void);
typedef double __v2df __attribute__ ((__vector_size__ (16)));
__v2df val;
void
foo (char *name, __v2df x, __v2df y, __v2df z)
{
if (!__builtin_ia32_comisdeq (z, val))
abort();
}
void
bar (char *name, ...)
{
__builtin_apply(foo, __builtin_apply_args(), 64);
}
int main(void)
{
__v2df x = { 3.1, 3.2 };
__v2df y = { 2.1, 5.2 };
__v2df z = { 1.1, 7.2 };
val = z;
bar("eeee", x, y, z);
return 0;
}
[hjl@gnu-tools-1 pr66754]$ make
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -m32 -msse2 -S -o x.s x.i
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -g -m32 -msse2 -o x x.s
./x
Makefile:12: recipe for target 'all' failed
make: *** [all] Aborted (core dumped)
[hjl@gnu-tools-1 pr66754]$
The vector parameters have the same issue. All arguments of vararg
functions argument are passed on stack while the first 3 vector arguments
are passed in registers for non-vararg functions.