On 31/05/2017 14:11:43, Richard Sandiford wrote: > Prakhar Bahuguna <prakhar.bahug...@arm.com> writes: > > On 31/05/2017 09:19:40, Richard Sandiford wrote: > >> const_ints are supposed to be stored in sign-extended form, so a 32-bit > >> integer with the MSB set should be 0xffffffff80000000|x instead of > >> 0x80000000|x. It's a bug if you have one where that isn't true. > >> > >> In the patch it looks like this could come from: > >> ...these two splits, where the GEN_INTs should probably be: > >> > >> gen_int_mode (..., SImode); > >> > >> instead. > > > > Hi Richard, thanks for the tip. Is there a test case that could produce an > > incorrect result? I've attempted to create one using negative doubles and > > floats but haven't succeeded. > > Just to check, are you testing with --enable-checking=yes,rtl? > > When the values you tried were split, did you get the sign-extended form > or the zero-extended form? > > Thanks, > Richard
I've now rebuilt with --enable-checking=yes,rtl and it appears that the split values are being correctly sign-extended in the rtl and appear correctly in the assembly. However, if you believe it is safer to use gen_int_mode(), I'll respin the patch accordingly. -- Prakhar Bahuguna
