Compilers for Soft Core Processors (as NIOS II)

Recently I browsed through some Alteras Nios II documents. That CPU seems to
have own instruction set depending from the size version. Further custom
instructions are possible to implement.

There are hints for all kind of developement toos including debuggers but I
was not able to find a C Compiler. As far as I understand it is intended
that designers have to use a free GNU Compiler.

As long as soft core processors have own instructions sets, that requieres
own code generators and special code optimizers in any compiler. As long as
many commercial compilers for off-the-shelf processors produce poor code,
one can imagine, that gnu optimization for soft cores will be worster.

If there is competition with more than one commercial compiler for one
architecture, the decision is either project history based or the compiler
with the better code size : runtime performance prevails.

Any experience with soft core compiler performance? Are soft cores a
chicken-egg problem ?


Relevant Pages

  • RE: A whopping 50 percent... ???
    ... < Michael Kraemer ... who cares about the instruction set when everybody uses ... But it does make a difference, speaking as a compiler writer. ... < when Power/PPC came around there wasn't such a large code base for it. ...
  • Re: RISC design, was What will Microsoft use its ARM license for?
    ... instruction set might be easier for compilers to deal with. ... Now the line goes that a compiler can deal with an irregular, ... RISC orthogonal because that's what PCC could dealt with. ...
  • Re: Guidelines for instruction set design?
    ... I'm not a compiler / system architecture expert, ... About my CPU architecture: ... a register hardwired to 0xFFFFFFFF ... like a problem related to the instruction set at first, ...
  • Re: Question about jumps
    ... What do you mean with "trust a compiler"? ... My tools do not exhaustively test the instruction set (I presume ... CPU and memory systems by driving them as hard as I can code. ... program will run on EVERY standard Linux installation. ...
  • Re: pic c
    ... instruction set and producing one instruction we have proof that we ... into a program the exact same size as the asm program. ... as part of a compiler validation excise. ... out what we did and extrapolating the implications. ...