macros, local variables...

[William Coleda]

A macro example in the docs shows:

.macro swap (A,B,TEMP) # . marks the directive
set .TEMP,.A # . marks the special variable.
set .A,.B
set .B,.TEMP
.endm # And . marks the end of the macro.

Is there a way to write this macro without specifying the TEMP parameter? For example, something like:

.macro swap (A,B)
.local pmc .TEMP
.TEMP = .A
.A = .B
.B = .TEMP
.endm

I've tried a few obvious permutations, but don't see anything that works as is.

[Michael Walter]

gensym, hehe. History repeats ;-)

- Michael

[Leopold Toetsch]

William Coleda wrote:
> A macro example in the docs shows:
>
> .macro swap (A,B,TEMP) # . marks the directive
> set .TEMP,.A # . marks the special variable.
> set .A,.B
> set .B,.TEMP
> .endm # And . marks the end of the macro.
>
>
> Is there a way to write this macro without specifying the TEMP
> parameter? For example, something like:
>
> .macro swap (A,B)
> .local pmc .TEMP

.local inside macros creates a local *label*.

As the macro arguments could be any kind of register, the macro can't
have the TEMP hidden inside. If you are gonna swap PMCs only, you could
write it as:

.macro swapP (A,B)
$P0 = .A
.A = .B
.B = $P0
.endm

(untested)

*But* we have an opcode called *exchange* ... It's even JITted on i386.

leo

[William Coleda]

Leopold Toetsch wrote:
> .macro swapP (A,B)
> $P0 = .A
> .A = .B
> .B = $P0
> .endm
>
> (untested)

Seems to work, thanks.

> *But* we have an opcode called *exchange* ... It's even JITted on i386.

This was just an example. Thanks.

> leo
>
>