Hi Jim:
Oh, I missed that pull request in github, Andrew's patch is better than our patch, you can just ignore our one. However I think this fix is kind of pre-requirement of rv32 glibc upstreaming, because Joseph want new port has all passed testsuite result. On Wed, Oct 3, 2018 at 10:46 AM Jim Wilson <j...@sifive.com> wrote: > > On Tue, Oct 2, 2018 at 7:23 PM Kito Cheng <kito.ch...@gmail.com> wrote: > > This patch is fixing the wrong behavior for unordered float compare > > for Signaling NaN, current implementation will suppress the FP > > exception flags unconditionally, however signaling NaN should signal > > an exception according IEEE 754-2008 spec. > > This looks related to > https://github.com/riscv/riscv-gcc/pull/119 > > That change wasn't committed at the time because it reduces > performance for everyone, even though only a few people depend on the > exact semantics the patch provides. One possible solution to that is > to add a -mieee option for people that want better IEEE conformance at > the expense of performance, and then enable the extra features with > -mieee. A few other ports already have various -mieee* options. > > IEEE 754 doesn't specify how C language operators work. My > understanding is that the RISC-V hardware and gcc port is implementing > all required features of IEEE fp as per the ISO C standard, but that > the glibc testsuite requires that some optional features be > implemented and we are missing these optional features. So there is a > tradeoff here, as to how to implement the optional features that few > people need without hurting performance for most people that don't > need them. > > I can look at your patches tomorrow. > > Jim
