On Sun, 11 Mar 2012 05:57:05 -0500, Manu <turkey...@gmail.com> wrote:
On 11 March 2012 04:35, Sean Cavanaugh <worksonmymach...@gmail.com> wrote:
On 3/10/2012 8:08 PM, Mantis wrote:
Tuple!(float, float) callee() {
do something to achieve result in st0,st1
fst st0, st1 into stack
load stack values into EAX, EDX
ret
}
void caller() {
call callee()
push EAX, EDX into a stack
fld stack values into st0, st1
do something with st0, st1
}
As opposed to:
Tuple!(float, float) callee() {
do something to achieve result in st0,st1
ret
}
void caller() {
call callee()
do something with st0, st1
}
Is there something I miss here?
Yes, the fact the FPU stack is deprecated :)
Don't dismiss the point, the same still stands true with XMM regs.
And Walter has talked about using the XMM registers to return floating point
data for exactly this reason. But those optimization apply to all structs and
all data types. There's nothing special about MRV. It has to return a set of
data in a structured manner; this is identical to the case of returning a
struct.
