Hi all,
There are two classes of instruction in the openrisc, class I and
class II. If a modified openrisc just implments class I instruction (for
saving resource), how can I avoid to generated the instruction of class
II in the compiler toolchain. I means if there are any options for avoiding
to generate the class II instructions.

One more question, If I want to add custom instruction set e.g.
multiply - accumulate in to the openrisc, is there any easy way to make
the complier to generate the instruction set except modifying the
compiler?

Thank you very much.

Best Regards,

Stephen

----- Original Message ----- From: whli_interqos@yahoo.com.hk> To: openrisc@opencores.org> Sent: Thursday, January 29, 2004 5:11 AM Subject: [openrisc] instruction set problem on openrisc
avoiding


Class II instructions by default are not generated by compiler.



That;s the only way. You have to modify compiler to generate your custom
insns.

regards,
Damjan

That;s the only way. You have to modify compiler to generate your custom
insns.

Hi Marko, Thank you for the advice. I put the the statement,#define MAC(x,y), into my source code. But it seems that there is not multiply-accumulate instruction in the asm code. Did I do anything wrong? Can you give more details on it? Thank you very much. Regards, Stephen Marko Mlinar markom@opencores.org> wrote:

That;s the only way. You have to modify compiler to generate your custom
insns.

I think Marko was suggesting that when you have implemented your own custom multiply-accumulate in your own special version of the CPU, you can access it from C code by using a #define. In this way, you don't have to modify the compiler. As you rightly say, there is no MAC instruction in the current instruction set. Robert Cragie, Design Engineer _______________________________________________________________ Jennic Ltd, Furnival Street, Sheffield, S1 4QT, UK http://www.jennic.com Tel: +44 (0) 114 281 2655 _______________________________________________________________ -----Original Message----- From: openrisc-bounces@opencores.org [mailto:openrisc-bounces@opencores.org]On Behalf Of li stephen Sent: 30 January 2004 03:28 To: List about OpenRISC project Subject: Re: [openrisc] instruction set problem on openrisc Hi Marko, Thank you for the advice. I put the the statement,#define MAC(x,y), into my source code. But it seems that there is not multiply-accumulate instruction in the asm code. Did I do anything wrong? Can you give more details on it? Thank you very much. Regards, Stephen Marko Mlinar markom@opencores.org> wrote: > > One more question, If I want to add custom instruction set e.g. > > multiply - accumulate in to the openrisc, is there any easy way to make > > the complier to generate the instruction set except modifying the > > compiler? > > That;s the only way. You have to modify compiler to generate your custom > insns. You can also make #define MAC(x,y), which will generate via asm statement "word 0xblabla" instruction. Marko _______________________________________________ http://www.opencores.org/mailman/listinfo/openrisc Shining Friends¡B¦n¤ß¦n³ø¡B·³¤ë¦pºq... ®öº©¹aÁn ±¡¤ß³sô http://ringtone.yahoo.com.hk/ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.opencores.org/forums/openrisc/attachments/20040130/b813ad2b/attachment.htm

There is l.mac in the current insn set, but it doesn't get generated by the compiler. I tried twice to have it generated by compiler and compiler just didn't want to emit the l.mac insn. If somebody else can figure out how to generated it directly with the compiler (in the or32.md machine description file) it would be great. regards, Damjan ----- Original Message ----- From: "Robert Cragie" rcc@jennic.com> To: "List about OpenRISC project" openrisc@opencores.org> Sent: Friday, January 30, 2004 9:27 AM Subject: RE: [openrisc] instruction set problem on openrisc
custom

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You can also make #define MAC(x,y), which will generate via asm statement "word 0xblabla" instruction. Marko _______________________________________________ http://www.opencores.org/mailman/listinfo/openrisc Shining Friends¡B¦n¤ß¦n³ø¡B·³¤ë¦pºq... ®öº©¹aÁn ±¡¤ß³sô http://ringtone.yahoo.com.hk/