I found it's easy to get the LLVM optimizer to emit code that hits this warning, see the test I added:
https://github.com/kripken/emscripten/commit/308e98787f88789431e5210d4defa76c275454ac The optimizer sees a union with an int write and a float read, and just forwards those bits into a float. On Tue, Nov 24, 2015 at 3:27 PM, Jukka Jylänki <[email protected]> wrote: > Btw, I did write a PR for being able to handle such arbitrary NaN literals > without warnings, but it was chosen not to merge that in, if I recall > correctly, the thinking was that it would be an impossible scenario to > occur. The related PR was here: > https://github.com/kripken/emscripten-fastcomp/pull/116 which was amended > to demote the handling to the warning you are seeing. It would be > interesting to hear what kind of code pattern does cause this. > > 2015-11-25 0:36 GMT+02:00 Alon Zakai <[email protected]>: > >> I added logging of the instruction and function on incoming now. It will >> also print out debug info if available. >> >> On Tue, Nov 24, 2015 at 8:29 AM, Robert Goulet < >> [email protected]> wrote: >> >>> Unfortunately that doesn't really help us track down what produced this >>> warning in our code. >>> >>> >>> On Tuesday, November 24, 2015 at 10:51:29 AM UTC-5, arnab choudhury >>> wrote: >>>> >>>> This error originates from the JS backend modifications to Clang-++.exe >>>> in the emscripten fastcomp project: >>>> >>>> >>>> https://github.com/kripken/emscripten-fastcomp/blob/4e83be90903250ec5142edc57971ed4c633c5e25/lib/Target/JSBackend/JSBackend.cpp >>>> >>>> Hope this helps. >>>> >>>> On Tuesday, November 24, 2015 at 7:28:15 AM UTC-8, Robert Goulet wrote: >>>>> >>>>> I got this warning at link time. I searched the code for this value >>>>> but couldn't find it. Is there any way to find which source file produce >>>>> this warning? EMCC_DEBUG=1 didn't tell more details about this. >>>>> Thanks! >>>>> >>>>> emcc: warning: cannot represent a NaN literal '0x5fec1ef10' with >>>>> custom bit pattern in NaN-canonicalizing JS engines (e.g. Firefox and >>>>> Safari) without erasing bits! >>>>> >>>>> Thanks! >>>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "emscripten-discuss" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "emscripten-discuss" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "emscripten-discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "emscripten-discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
