[llvm-commits] [PATCH]: ppc32 va_arg() implementation

[Roman Divacky]

On Tue, Jun 14, 2011 at 01:09:07PM -0700, Eli Friedman wrote:
> On Tue, Jun 14, 2011 at 1:02 PM, Roman Divacky <rdivacky at freebsd.org> wrote:
> > On Tue, Jun 14, 2011 at 12:59:18PM -0700, Eli Friedman wrote:
> >> On Tue, Jun 14, 2011 at 12:47 PM, Roman Divacky <rdivacky at freebsd.org> wrote:
> >> > Hi,
> >> >
> >> > the attached patch implements va_arg() lowering on ppc32.
> >> > Ints (8, 16, 32 and also 64 bits that need special treatment) work,
> >> > floats don't work (neither with gcc - we should warn when someone tries
> >> > to use them on ppc32 probably), doubles do work.
> >>
> >> It's impossible to make any C frontend generate a call to a varargs
> >> function that actually passes in something of type "float"... are you
> >> sure you're testing correctly?
> >
> > This is an example with doubles, to change it to floats you just
> > change the type and the literal passed in. Am I doing something wrong?:
> >
> > void bar(int w, ...) {
> > ?double d;
> > ?va_list ap;
> > ?va_start(ap, w);
> >
> > ?printf("\n\n");
> > ?do {
> > ? ?d = va_arg(ap, double);
> > ? ?printf("d = %f\n", d);
> > ?} while (d != 0.0);
> > ?va_end(ap);
> > }
> >
> > int main() {
> > ?bar(1, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 0.0);
> > }
> >
> 
> Changing the type of the literal passed in doesn't change the
> generated code; they get promoted them to doubles.

Yes, but when I use va_arg(ap, float) it does not work (crashes gcc, generates
the wrong result with llvm+my patch).