Attached is a pod - describing the current existing stack calling convention - proposing a syntax for parrot's NCI calling convention.
Comments ... welcome, leo
=head1 NAME IMCC - calling conventions =head1 VERSION =over 4 =item 0.1 intital proposal =back =head1 OVERVIEW This document describes subroutine calling conventions. =head1 DESCRIPTION A imcc does register allocation, it has to track the life span of variables. This includes the (possible) data flow in and out of subroutines. =head1 Stack calling conventions Arguments are B<save>d in reverse order onto the user stack: .arg y # save args in reversed order .arg x call _foo #(r, s) = _foo(x,y) .local int r .local int s .result s # restore results in reversed order .result r # [1] and return values are B<restore>d in reversed order from there. The subroutine is responsible for preserving registers. .sub _foo # sub foo(int a, int b) saveall .param int a .param int b ... .return pl # return (pl, mi) .return mi # [1] restoreall ret .end [1] or vice versa? =head1 Parrot calling conventions (NCI) Proposed syntax: $P0 = load_lib "libname" $P1 = dlfunc $P0, "funcname", "signature" .nciarg z # I5 .nciarg y # I6 .nciarg x # I7 ncicall $P1 # r = funcname(x, y, z) .nciresult r This prepares parameters like described in pdd03_calling_conventions.pod, saves the registers and invokes the function. =head1 Parrot calling conventions (Method calls) TBD. =head1 Namespaces and lexicals - Should imcc keep track of pad opcodes? - Should imcc even emit such opcodes from e.g. .local directives? =head1 FILES F<imcc.y>, F<t/syn/bsr.t> =head1 AUTHOR Leopold Toetsch <[EMAIL PROTECTED]>
