Thank you for all your kindly help make the issue more clear. Currently, we would disable abssi2 pattern and the soft-fp could work correctly. Thanks all the explanation and assistance. I really appreciate it.
2013/6/30 Joseph S. Myers <jos...@codesourcery.com>: > On Sun, 30 Jun 2013, Shiva Chen wrote: > >> But how the target generate abs instruction if the target abs have >> saturation behavior ? >> We couldn't use abssi2 naming pattern and ss_abssi2 naming pattern >> doesn't exist. > > If you want to use a saturating abs instruction for C code that exhibits > undefined behavior in cases where the instruction saturates, you need to > add support for ss_abssi2 patterns and teach the GIMPLE-to-RTL conversion > to use such patterns as appropriate (in the absence of -fwrapv/-ftrapv, of > course). > > -- > Joseph S. Myers > jos...@codesourcery.com
