From:	MERC::"uunet!WKUVX1.BITNET!MacroMan" 26-APR-1992 16:05:07.73
To:	MACRO32@WKUVX1.BITNET
CC:	
Subj:	Re: BLISS vs. C: Which is the better language for

> >LOCC is also outside the "core" instruction set of the VAX architecture --
> >subset implementations mostly leave it out.  Unfortunately, this includes
> >most (all?) of the CVAX (3xxx, 6xxx) line ... (not to mention mypoor lowly
> >VAXstation II 8-( )
>
> Not completely true.  My KA630-AA CPU Module User's Guide (EK-KA630-UG-001)
> states that the MicroVAX II CPU chip provides special microcode "hooks"
> to aid the emulation of the character string instructions, except for
> MOVC3 and MOVC5 (which are implemented on the chip).
>
> However, the KA650 CPU Module Technical Manual (EK-KA650-UG-001) states
> that the character string instructions MOVC3, MOVC5, CMPC3, CMPC5, LOCC,
> SCANC, SKPC and SPANC are implemented in the chip's microcode and all
> other character string instructions have a special microcode assistance
> for emulation software.
>
> So the situation changed from the MicroVAX II CPU chip to the MicroVAX 3000
> CPU chip.  I thought that the remaining 3000s, the 6000s and the 4000s
> CPU chips implemented the same subset as the KA650 CPU.

Readers of INFO-VAX may remember, that I posted an instruction timing
program and collected results.

Here are the times for the LOCC instruction (ns for 10000 bytes):

MVAX3300        4476340
MVAX3400        4478316
MVAX3600        3826592
MVAX3900        2595048
MVAXII         31424986
VAX4200         1933768
VAX4300         2155600
VAX4500         1027908
VAX6300         3040964
VAX6400         2200260
VAX6600          858988
VAX780          4396876
VAX8350         3899428
VAX8600         1007804
VAX8650          671336
VAX8700          745972
VAX8800          646204
VAX9200           57000
VAX9400           45096
VAXS2000       33322804
VAXS3100-30     3918636
VAXS3100-38     3889768
VAXS3100-58     4612876
VAXS3100-76     2122200
VAXS3200        3917992
VAXS4000-60     1333856

We see, that LOCC is much faster on the VAX 3x00 than microVAX II, but not
quite as fast as the "old VAX'es" (8600,8650,8700,8800).

PS: Remember to adjust for machinepower (f.ex. MVUPS), when you compare
the numbers above.

                                                          Arne Vajhxj

Arne Vajhxj                             local DECNET:  KO::ARNE
Computer Department                     PSI:           PSI%238310013040::ARNE
Business School of Southern Denmark     Internet:      ARNE@KO.HHS.DK