Richard Sandiford <richard.sandif...@linaro.org> writes: > The make_field_assignment code: > > src = force_to_mode (src, mode, > GET_MODE_PRECISION (mode) >= HOST_BITS_PER_WIDE_INT > ? HOST_WIDE_INT_M1U > : (HOST_WIDE_INT_1U << len) - 1, > 0); > > would ignore the field length len for DImode, even though DImode can be > handled using HWIs. I think the code should be testing len instead. > > The patch was originally part of the SVE machine_mode series. > Retesting showed that it changed the asm output on powerpc for a few > tests, so I thought it should go in separately. Each test change > seemed to be an improvement. > > Tested on aarch64-linux-gnu and x86_64-linux-gnu. I no longer have > access to the compile farm to test on the powerpc boxes there.
Now tested on powerpc64le-linux-gnu too (thanks to Segher for the access). > Thanks, > Richard > > > 2017-05-24 Richard Sandiford <richard.sandif...@linaro.org> > > gcc/ > * combine.c (make_field_assignment): Check len rather than the mode > precision when calling force_to_mode. > > Index: gcc/combine.c > =================================================================== > --- gcc/combine.c 2017-05-03 08:46:32.777861592 +0100 > +++ gcc/combine.c 2017-05-24 09:25:25.170351268 +0100 > @@ -9634,7 +9634,7 @@ make_field_assignment (rtx x) > other, pos), > dest); > src = force_to_mode (src, mode, > - GET_MODE_PRECISION (mode) >= HOST_BITS_PER_WIDE_INT > + len >= HOST_BITS_PER_WIDE_INT > ? HOST_WIDE_INT_M1U > : (HOST_WIDE_INT_1U << len) - 1, > 0);
