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

[Eli Friedman]

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.

-Eli