| Message ID | 87r2s3lccy.fsf@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Make VEC_PERM_EXPR work for variable-length vectors | expand |
On Sun, Dec 10, 2017 at 12:18 AM, Richard Sandiford <richard.sandiford@linaro.org> wrote: > The patch to remove the vec_perm_const optab checked whether replacing > a constant permute with a variable permute is safe, or whether it might > truncate the indices. This patch adds a corresponding check for whether > variable permutes can be lowered to QImode-based permutes. Ok. > > 2017-12-09 Richard Sandiford <richard.sandiford@linaro.org> > > gcc/ > * optabs-query.c (can_vec_perm_var_p): Check whether lowering > to qimode could truncate the indices. > * optabs.c (expand_vec_perm_var): Likewise. > > Index: gcc/optabs-query.c > =================================================================== > --- gcc/optabs-query.c 2017-12-09 22:47:21.534314227 +0000 > +++ gcc/optabs-query.c 2017-12-09 22:47:25.861316866 +0000 > @@ -378,7 +378,8 @@ can_vec_perm_var_p (machine_mode mode) > > /* We allow fallback to a QI vector mode, and adjust the mask. */ > machine_mode qimode; > - if (!qimode_for_vec_perm (mode).exists (&qimode)) > + if (!qimode_for_vec_perm (mode).exists (&qimode) > + || GET_MODE_NUNITS (qimode) > GET_MODE_MASK (QImode) + 1) > return false; > > if (direct_optab_handler (vec_perm_optab, qimode) == CODE_FOR_nothing) > Index: gcc/optabs.c > =================================================================== > --- gcc/optabs.c 2017-12-09 22:47:23.878315657 +0000 > +++ gcc/optabs.c 2017-12-09 22:47:25.861316866 +0000 > @@ -5595,7 +5595,8 @@ expand_vec_perm_var (machine_mode mode, > /* As a special case to aid several targets, lower the element-based > permutation to a byte-based permutation and try again. */ > machine_mode qimode; > - if (!qimode_for_vec_perm (mode).exists (&qimode)) > + if (!qimode_for_vec_perm (mode).exists (&qimode) > + || GET_MODE_NUNITS (qimode) > GET_MODE_MASK (QImode) + 1) > return NULL_RTX; > icode = direct_optab_handler (vec_perm_optab, qimode); > if (icode == CODE_FOR_nothing)
Index: gcc/optabs-query.c =================================================================== --- gcc/optabs-query.c 2017-12-09 22:47:21.534314227 +0000 +++ gcc/optabs-query.c 2017-12-09 22:47:25.861316866 +0000 @@ -378,7 +378,8 @@ can_vec_perm_var_p (machine_mode mode) /* We allow fallback to a QI vector mode, and adjust the mask. */ machine_mode qimode; - if (!qimode_for_vec_perm (mode).exists (&qimode)) + if (!qimode_for_vec_perm (mode).exists (&qimode) + || GET_MODE_NUNITS (qimode) > GET_MODE_MASK (QImode) + 1) return false; if (direct_optab_handler (vec_perm_optab, qimode) == CODE_FOR_nothing) Index: gcc/optabs.c =================================================================== --- gcc/optabs.c 2017-12-09 22:47:23.878315657 +0000 +++ gcc/optabs.c 2017-12-09 22:47:25.861316866 +0000 @@ -5595,7 +5595,8 @@ expand_vec_perm_var (machine_mode mode, /* As a special case to aid several targets, lower the element-based permutation to a byte-based permutation and try again. */ machine_mode qimode; - if (!qimode_for_vec_perm (mode).exists (&qimode)) + if (!qimode_for_vec_perm (mode).exists (&qimode) + || GET_MODE_NUNITS (qimode) > GET_MODE_MASK (QImode) + 1) return NULL_RTX; icode = direct_optab_handler (vec_perm_optab, qimode); if (icode == CODE_FOR_nothing)