On Sun, Dec 10, 2017 at 12:08 AM, Richard Sandiford <richard.sandif...@linaro.org> wrote: > The vec_perm code falls back to doing byte-level permutes if > element-level permutes aren't supported. There were two copies > of the code to calculate the mode, and later patches add another, > so this patch splits it out into a helper function. >
Ok. > 2017-12-09 Richard Sandiford <richard.sandif...@linaro.org> > > gcc/ > * optabs-query.h (qimode_for_vec_perm): Declare. > * optabs-query.c (can_vec_perm_p): Split out qimode search to... > (qimode_for_vec_perm): ...this new function. > * optabs.c (expand_vec_perm): Use qimode_for_vec_perm. > > Index: gcc/optabs-query.h > =================================================================== > --- gcc/optabs-query.h 2017-12-09 22:47:12.476364764 +0000 > +++ gcc/optabs-query.h 2017-12-09 22:47:14.730310076 +0000 > @@ -174,6 +174,7 @@ enum insn_code can_extend_p (machine_mod > enum insn_code can_float_p (machine_mode, machine_mode, int); > enum insn_code can_fix_p (machine_mode, machine_mode, int, bool *); > bool can_conditionally_move_p (machine_mode mode); > +opt_machine_mode qimode_for_vec_perm (machine_mode); > bool can_vec_perm_p (machine_mode, bool, vec_perm_indices *); > /* Find a widening optab even if it doesn't widen as much as we want. */ > #define find_widening_optab_handler(A, B, C) \ > Index: gcc/optabs-query.c > =================================================================== > --- gcc/optabs-query.c 2017-12-09 22:47:12.476364764 +0000 > +++ gcc/optabs-query.c 2017-12-09 22:47:14.729310075 +0000 > @@ -345,6 +345,22 @@ can_conditionally_move_p (machine_mode m > return direct_optab_handler (movcc_optab, mode) != CODE_FOR_nothing; > } > > +/* If a target doesn't implement a permute on a vector with multibyte > + elements, we can try to do the same permute on byte elements. > + If this makes sense for vector mode MODE then return the appropriate > + byte vector mode. */ > + > +opt_machine_mode > +qimode_for_vec_perm (machine_mode mode) > +{ > + machine_mode qimode; > + if (GET_MODE_INNER (mode) != QImode > + && mode_for_vector (QImode, GET_MODE_SIZE (mode)).exists (&qimode) > + && VECTOR_MODE_P (qimode)) > + return qimode; > + return opt_machine_mode (); > +} > + > /* Return true if VEC_PERM_EXPR of arbitrary input vectors can be > expanded using SIMD extensions of the CPU. SEL may be NULL, which > stands for an unknown constant. Note that additional permutations > @@ -375,9 +391,7 @@ can_vec_perm_p (machine_mode mode, bool > return true; > > /* We allow fallback to a QI vector mode, and adjust the mask. */ > - if (GET_MODE_INNER (mode) == QImode > - || !mode_for_vector (QImode, GET_MODE_SIZE (mode)).exists (&qimode) > - || !VECTOR_MODE_P (qimode)) > + if (!qimode_for_vec_perm (mode).exists (&qimode)) > return false; > > /* ??? For completeness, we ought to check the QImode version of > Index: gcc/optabs.c > =================================================================== > --- gcc/optabs.c 2017-12-09 22:47:12.476364764 +0000 > +++ gcc/optabs.c 2017-12-09 22:47:14.731310077 +0000 > @@ -5452,9 +5452,7 @@ expand_vec_perm (machine_mode mode, rtx > > /* Set QIMODE to a different vector mode with byte elements. > If no such mode, or if MODE already has byte elements, use VOIDmode. */ > - if (GET_MODE_INNER (mode) == QImode > - || !mode_for_vector (QImode, w).exists (&qimode) > - || !VECTOR_MODE_P (qimode)) > + if (!qimode_for_vec_perm (mode).exists (&qimode)) > qimode = VOIDmode; > > /* If the input is a constant, expand it specially. */