| Message ID | 20201126084342.GQ3788@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | gimple-fold: Use DECL_PADDING_P in __builtin_clear_padding | expand |
On Thu, 26 Nov 2020, Jakub Jelinek wrote: > Hi! > > On Wed, Nov 25, 2020 at 12:26:17PM -0500, Jason Merrill wrote: > > I think you want to check DECL_PADDING_P here; the C and C++ front ends set > > it on unnamed bit-fields, and that's what is_empty_type looks at. > > While the above has been written in the context of __builtin_bit_cast patch, > I think it applies to __builtin_clear_padding too. > > So this patch implements that. The C FE sets DECL_PADDING_P solely on the > DECL_BIT_FIELD !DECL_NAME FIELD_DECLs, the C++ FE sets it on those and in > another spot I haven't really figured out what it is about. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? OK. Richard. > 2020-11-26 Jakub Jelinek <jakub@redhat.com> > > * gimple-fold.c (clear_padding_union): Ignore DECL_PADDING_P > fields. > (clear_padding_type): Ignore DECL_PADDING_P fields, rather than > DECL_BIT_FIELD with NULL DECL_NAME. > > --- gcc/gimple-fold.c.jj 2020-11-25 10:37:44.997297061 +0100 > +++ gcc/gimple-fold.c 2020-11-25 18:45:04.380442914 +0100 > @@ -4327,7 +4327,7 @@ clear_padding_union (clear_padding_struc > } > > for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) > - if (TREE_CODE (field) == FIELD_DECL) > + if (TREE_CODE (field) == FIELD_DECL && !DECL_PADDING_P (field)) > { > if (DECL_SIZE_UNIT (field) == NULL_TREE) > { > @@ -4455,13 +4455,11 @@ clear_padding_type (clear_padding_struct > HOST_WIDE_INT cur_pos; > cur_pos = 0; > for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) > - if (TREE_CODE (field) == FIELD_DECL) > + if (TREE_CODE (field) == FIELD_DECL && !DECL_PADDING_P (field)) > { > tree ftype = TREE_TYPE (field); > if (DECL_BIT_FIELD (field)) > { > - if (DECL_NAME (field) == NULL_TREE) > - continue; > HOST_WIDE_INT fldsz = TYPE_PRECISION (ftype); > if (fldsz == 0) > continue; > > > Jakub > >
--- gcc/gimple-fold.c.jj 2020-11-25 10:37:44.997297061 +0100 +++ gcc/gimple-fold.c 2020-11-25 18:45:04.380442914 +0100 @@ -4327,7 +4327,7 @@ clear_padding_union (clear_padding_struc } for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) - if (TREE_CODE (field) == FIELD_DECL) + if (TREE_CODE (field) == FIELD_DECL && !DECL_PADDING_P (field)) { if (DECL_SIZE_UNIT (field) == NULL_TREE) { @@ -4455,13 +4455,11 @@ clear_padding_type (clear_padding_struct HOST_WIDE_INT cur_pos; cur_pos = 0; for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) - if (TREE_CODE (field) == FIELD_DECL) + if (TREE_CODE (field) == FIELD_DECL && !DECL_PADDING_P (field)) { tree ftype = TREE_TYPE (field); if (DECL_BIT_FIELD (field)) { - if (DECL_NAME (field) == NULL_TREE) - continue; HOST_WIDE_INT fldsz = TYPE_PRECISION (ftype); if (fldsz == 0) continue;