Tejas Joshi <tejasjoshi9...@gmail.com> writes: > Hello. > I just wanted to make sure that I am looking at the correct code here. > Except for rtl.def where I should be introducing something like > float_contract (or float_narrow?) and also simplify-rtx.c, breakpoints > set on functions around expr.c, cfgexpand.c where I grep for > float_truncate/FLOAT_TRUNCATE did not hit. > Also, in what manner should float_contract/narrow be different from > float_truncate as both are trying to do similar things? (truncation > from DF to SF)
I think the code should instead be a fused addition and truncation, a bit like FMA is a fused addition and multiplication. Describing it as a DFmode addition followed by some conversion to SF would still involve double rounding. simplify-rtx.c is probably the most important place to handle it. It would be easiest to test using the selftests at the end of the file. Thanks, Richard
