C54x port: some general technical questions

[James E Wilson]

Jonathan Bastien-Filiatrault wrote:
> * We have defined BIT_PER_WORD to 16 and UNITS_PER_WORD to 1. On this
> DSP, there are two 40-bits accumulators. How do we make GCC take
> advantage of this and which machine mode do we use ?

GCC has little support for non-power-of-2 sized accumulators. 
Traditionally this would be done by using PSImode (because your target 
has a 64-bit SImode), which you can enable by using the undocumented 
PARTIAL_INT_MODE(SI) macro in your target modes.def file.  See other 
targets for existing examples of this.

Also, gcc has little support for targets with BITS_PER_UNIT != 8.  I 
think the (ti)c4x is the only one currently supported, and it is being 
obsoleted due to lack of maintenance.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com