Apple Porting To PowerPC Jun1993

R&D University Porting to PowerPC ( sitv ," { ... PowerPC .dl ij''":oftllb ,.";' : .,.J:>£,--:1 :.' '>~", :)dt\Ulration strategies for PowerPC ' . ,. , ..' . d'C ,an4'~;Th1i;-,b~YF;become the ~~9h~p()~~~§ this decade, and most of the development tools that are available are geared towards these languages. Because of this, the earliest PowerPC development tools will be oriented towards C and C+ + programmers. However, since many ,". devel~ve WtlitmrlttlllffiIlflmductsirt Wt~es.()ther than C or C+ +, we'll take a quick look at theii:i{iptions WffioVing11OipowerPC. ' '. 811'r g.lig;,_"j:)IDilor-:;n, '. , li1 ~)!i;, Gii'. ,., .. ).)" _ . Pascal Development ,')JHJO?, I"IJ ~i;' Pascal developers have a{ew:~when ~~ng-the.ir code to PowerPC: - Wai~ for:a third-party Pasca[compiler~MetroWer~ is producing a Pascal compilers for PowerPC. ~:~b::~~~~~!~j~~~~~.oo:~t~p~:who - Re~ U'fC or C+ +: This approach, while potentially difficult, gives you the widest range of po :::.;Wityloptions to PowerPC and other p1a,tfonJ1S (ifyou should ever choose to go crosspla tp', '; 1;HH rol - uset~:;:;as.ql t~~conversion tool: Sierra ~~are has produced "~2C", which converts P~ or Object PjlSCal to QC+ +. Several groups Wlthm Apple have used thIS too~ and most of them didn't like~W~fe ~ loo~~g for a better solution. , ..... ' uJ~h~I;j~!~~Hd:_:(a spin-off of Bell Labs) makes "FlashPort", a tool which treats your compiled application as the input to a compiler which emits PowerPC object code. This yields an application which is faster than a strictly emulated 680xO application, but somewhat slower and larger than an applkation re-compiled for PowerPC from its original sources. " - Port as ~tich as ~ible/and emulate non-portable parts via Mixed mode: This is a reasonable ) ~atq~gy.~rtt}t.~a~~me parts of your code that are not processor intensive and which would be (,~~4hp:~()!f/«Q~ever, remember that you will not get the full performance benefits that a .lm~re '&rWplele pbhmg job would yield. Assembly-Language Development Assembly-language programmers cannot simply re-compile for PowerPC; some sort of porting will be required Our recommendation is that you re-write your assembly code as portable C source code. While many assembly language programmers feel that this is a poor chOice, the design of the PowerPC Macintosh removes many of the reasons that developers write in assembly language. The 4 major reasons developers write in assembly language are 1) speed, 2) linking different calling conventions together, 3) addressing custom hardware installed in a particular machine, or 4) a need to jump to a particular routine instead of using a subroutine call. We'll look at how the PowerPC programming model addresses each of these issues. Migration Strategies for PowerPC Page 1 • The first case, speed, should be handled adequately by the optimizing Ccompilers. Creating optimized code for the PowerPC is no easy feat, and it is easy to overlook one rule or another wh…