cmpsi2 library calls?

[Richard Earnshaw (lists)]

On 26/10/2018 00:46, Paul Koning wrote:
> In my target (pdp11) which has 16 bit words, I see some test suite failures because of unresolved references to __cmpsi2.  The strange thing is that most of the time 32 bit compares are expanded by GCC into a sequence of word compares and branches.
> 
> Why would GCC sometimes generate library calls for this?  Can I make it stop doing that by writing patterns (define_expand or define_insn) for cmpsi2?  That may be useful because I think I can generate better code, but still it's puzzling that the behavior is inconsistent.
> 
> 	paul
> 

Yes.  See, for example, the analogous case in the ARM port for cmpdi2.

R.