| Message ID | 87efvezmdl.fsf@linaro.org |
|---|---|
| State | New |
| Headers | show |
Richard Sandiford <richard.sandiford@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.sandiford@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);
Ping Richard Sandiford <richard.sandiford@linaro.org> writes: > Richard Sandiford <richard.sandiford@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.sandiford@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);
> 2017-05-24 Richard Sandiford <richard.sandiford@linaro.org> > > gcc/ > * combine.c (make_field_assignment): Check len rather than the mode > precision when calling force_to_mode. OK for mainline.
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);
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. Thanks, Richard 2017-05-24 Richard Sandiford <richard.sandiford@linaro.org> gcc/ * combine.c (make_field_assignment): Check len rather than the mode precision when calling force_to_mode.