On 08/15/2018 06:57 AM, Tamar Christina wrote: > Hi All, > > This patch fixes an ICE that would happen when extract_low_bits > is called with modes for which you can't extract a valid subreg. > e.g. taking a 32 bytes subreg from a 48 byte mode. > > The ICE happens because convert_modes which eventually calls > simplify_gen_subreg does not expect the convertion to fail. > > The assert in gen_lowpart_general would then be hit. The patch > changes it to validate the subreg before trying to convert the > modes. If the subreg is not possible we return NULL_RTX and bail > out early. > > I don't have a target independent test for this because it depends > on the target having a 48byte mode and using it for loads. > > Cross compiled and regtested on > aarch64_be-none-elf > and no issues > > Boostrapped and regtested > aarch64-none-linux-gnu > > and found no issues. > > Bootstrapped on > x86_64-pc-linux-gnu > arm-none-linux-gnueabihf > > and no issues. > > Ok for trunk? > > Thanks, > Tamar > > gcc/ChangeLog: > > 2018-08-15 Tamar Christina <tamar.christ...@arm.com> > > * expmed.c (extract_low_bits): Reject invalid subregs early. > > gcc/testsuite/ChangeLog: > > 2018-08-15 Tamar Christina <tamar.christ...@arm.com> > > * gcc.target/aarch64/large_struct_copy.c: New test. > OK. jeff