* 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.
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Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com
