Figure 6 shows the exec ution of a trans lated im age under AU D I . Note that both the BASIC image (HELLO_WORLD) and the BASIC: r u n-time l i brary (BASRTL) are translated . Run-time l ibraries that are
used by the AUDI environment cannot be translated
under AU D I . Translating run-time l ibraries that Al !DI
itself uses causes a "circularity in activation·· and incorrect or no execution.
In the H EL LO_ WORLD example, there are 2H calls
to VA X ro utines, most l i kely those to LI BRTL and
8 0 8 5 A l p h a A X P i n s t r u c t i o n s w e r e e x e c u t e d . T I E L o o k u p s : S t a y e d i n A l p h a A X P r o u t i n e s : W e n t t o V A X r o u t i n e s : T o t a l : C A L L x 4 2 8 3 2 J S B 5 0 5 J M P 0 0 0 2 8 V A X r e t u r n s u s e d ( 2 8 R E T , 0 R S B ) t o r e s u m e A l p h a A X P c o d e . T h e r e w e r e n o F a u l t - O n - E x e c u t e c o n d i t i o n s c o n v e r t e d t o L o o k u p s . 2 1 C A L L x C o n t e x t B l o c k s w e r e a l l o c a t e d - w h i c h w e r e r e u s e d 7 t i m e s . T h e r e w e r e 1 9 T I E - b a s e d ' c o m p l e x i n s t r u c t i o n s ' e x e c u t e d . I n s t r u c t i o n I N S Q U E C O E ) 2 I n s t r u c t i o n M O V C 3 C 2 8 ) 8 I n s t r u c t i o n M O V C 5 C 2 C ) 8 I n s t r u c t i o n M O V T U C C 2 F ) 1 T h e r e w a s 1 V A X r o u t i n e c a l l t o A l p h a A X P c o d e . T h e r e w e r e 2 i m a g e s c o n t a i n i n g A l p h a A X P c o d e : H E L L O _W O R L D _T V X O . O f r o m B L 3 . 3 V E S T o f M a r 3 0 1 9 9 2 0 9 : 2 7 : 0 2 B A S R T L T V X O . O f r o m B L 3 . 3 V E S T o f M a r 3 0 1 9 9 2 0 9 : 1 4 : 1 0 E x e c u t i o n d e p e n d e d o n L I B R T L_ T V M T H R T L_ T V T I E $ S H A R E M Q N $ S H A R E D E C W $ D W T L I B S H R L B R S H R t h e s e i m a g e s : D E C W $ X L I B S H R D E C W $ T R A N S P O R T C O M M O N V A X C R T L M T H R T L C O N V S H R S O R T S H R L I B R T L 2 L I B R T L D B G S S I S H R
Figure 6 A UDI Emm.pte-Translated Hello World Image
Op enVMS system services. There are 2 1 u n i que CALLx contexts and 7 reused ones. In addition, the example uses fou r different comp lex i nstructions.
Summary
The software s i m u lators Mannequ i n , ISP, Al ii). ancl A!JDI greatly aided Al pha AXP software porting ami development efforts. Substantial parts of both system and application software were simu la ted and ve rified concurrently with hardware devel op
ment. When Alpha AXP hardware became avai lable, most software cou ld be plugged i n simply and ran exactly as ex pected. The use of t hese simulation tools saved a year or more from the overa l l Alpha AX!' sched u l e .
Acknowledgments
Many people throughou t Digital con tributed to the su ccess of the Alpha AXP simu la tors. Hom:1yoon Ak h iani, Ray Lanza , Stephan Meier, Steve Morr is, Andrew Payne, ancl Jon Reeves worked on the ISP
model . George Da rcy. Mark Herdeg, Kevin Koch, Eric Rasm ussen, and Scott Robinson contributed to the Mannequin si m u lator. The All D effort incl uclecl several groups from across D igita l . Their pri mary contribu tors were \Valrer Arbo, Ronald Brender, Henry Grieb, Mark Herdeg, Michael lies . .fa mes Jo h nson. Robert Landa u , Maurice Marks. Dennis
1 9 2
Murphy, Scott Robi nson, Larry Woodman, and James Woold ridge. Final ly, much of the A DI information i n this article is taken from work origi nally clone by Scott Robinson. Other AliDI contribu tors include George Darcy, Mark Herdeg, Matthew Kirk, Naghmeh Mirghafori, and Murari Srinivasa n .
References
I . R. Sites, eel . , Alp/Ja Architecture Reference Manual (Burlington. :VIA: D igita l Press, 1992) 2. C Thac ker, D. Conroy, and L Stewart, " The
Alpha Demonstration Unit: A High-performa nce M u l t iprocessor fo r Software ami Chip Devel opment." Digital TechnicaiJounwl, vol . 4, no. 4
( 1992, this issue) 'i l-6'i
:). Open VMS Delta/XDel ta Utility klanual (Ylayn:ml Digita l Equ ipmen t Corporation, Order No. A A-PQYPA-TK,
1992)
4. S. Mishra, ''The VAX H800 Microarchitecture,"
Digital Teclm icalJournal, vol . L no. 4 (February 1987): 20-:):)
'i R. Sites, A. Chern off, M. Kirk, M. Marks, and S. Robinson . " Bi nary Translation," D(!{ital Tecbniutl.fournal, vol . 4, no. 4 ( 1992, this issue): 137- 1)2.