On Sat, 5 Aug 2023, Jiufu Guo wrote:

> 
> Hi,
> 
> Richard Biener <rguent...@suse.de> writes:
> 
> > On Thu, 3 Aug 2023, Jiufu Guo wrote:
> >
> >> 
> >> Hi Richard,
> >> 
> >> Richard Biener <rguent...@suse.de> writes:
> >> 
> >> > On Tue, 1 Aug 2023, Jiufu Guo wrote:
> >> >
> >> >> 
> >> >> Hi,
> >> >> 
> >> >> Richard Biener <rguent...@suse.de> writes:
> >> >> 
> >> >> > On Mon, 24 Jul 2023, Jiufu Guo wrote:
> >> >> >
> >> >> >> 
> >> >> >> Hi Martin,
> >> >> >> 
> >> >> >> Not sure about your current option about re-using the ipa-sra code
> >> >> >> in the light-expander-sra. And if anything I could input please
> >> >> >> let me know.
> >> >> >> 
> >> >> >> And I'm thinking about the difference between the expander-sra, 
> >> >> >> ipa-sra
> >> >> >> and tree-sra. 1. For stmts walking, expander-sra has special behavior
> >> >> >> for return-stmt, and also a little special on assign-stmt. And phi
> >> >> >> stmts are not checked by ipa-sra/tree-sra. 2. For the access 
> >> >> >> structure,
> >> >> >> I'm also thinking if we need a tree structure; it would be useful 
> >> >> >> when
> >> >> >> checking overlaps, it was not used now in the expander-sra.
> >> >> >> 
> >> >> >> For ipa-sra and tree-sra, I notice that there is some similar code,
> >> >> >> but of cause there are differences. While it seems the difference
> >> >> >> is 'intended', for example: 1. when creating and accessing,
> >> >> >> 'size != max_size' is acceptable in tree-sra but not for ipa-sra.
> >> >> >> 2. 'AGGREGATE_TYPE_P' for ipa-sra is accepted for some cases, but
> >> >> >> not ok for tree-ipa.  
> >> >> >> I'm wondering if those slight difference blocks re-use the code
> >> >> >> between ipa-sra and tree-sra.
> >> >> >> 
> >> >> >> The expander-sra may be more light, for example, maybe we can use
> >> >> >> FOR_EACH_IMM_USE_STMT to check the usage of each parameter, and not
> >> >> >> need to walk all the stmts.
> >> >> >
> >> >> > What I was hoping for is shared stmt-level analysis and a shared
> >> >> > data structure for the "access"(es) a stmt performs.  Because that
> >> >> > can come up handy in multiple places.  The existing SRA data
> >> >> > structures could easily embed that subset for example if sharing
> >> >> > the whole data structure of [IPA] SRA seems too unwieldly.
> >> >> 
> >> >> Understand.
> >> >> The stmt-level analysis and "access" data structure are similar
> >> >> between ipa-sra/tree-sra and the expander-sra.
> >> >> 
> >> >> I just update the patch, this version does not change the behaviors of
> >> >> the previous version.  It is just cleaning/merging some functions only.
> >> >> The patch is attached.
> >> >> 
> >> >> This version (and tree-sra/ipa-sra) is still using the similar
> >> >> "stmt analyze" and "access struct"".  This could be extracted as
> >> >> shared code.
> >> >> I'm thinking to update the code to use the same "base_access" and
> >> >> "walk function".
> >> >> 
> >> >> >
> >> >> > With a stmt-leve API using FOR_EACH_IMM_USE_STMT would still be
> >> >> > possible (though RTL expansion pre-walks all stmts anyway).
> >> >> 
> >> >> Yeap, I also notice that "FOR_EACH_IMM_USE_STMT" is not enough.
> >> >> For struct parameters, walking stmt is needed.
> >> >
> >> > I think I mentioned this before, RTL expansion already
> >> > pre-walks the whole function looking for variables it has to
> >> > expand to the stack in discover_nonconstant_array_refs (which is
> >> > now badly named), I'd appreciate if the "SRA" walk would piggy-back
> >> > on that existing walk.
> >> 
> >> I may misunderstand your meaning about 'stmt-level analysis' and
> >> 'pre-walk'.
> >> I understand it as 'walk to analyze each stmt in each bb'.
> >> In 'discover_nonconstant_array_refs', there is a 'walk_gimple_op':
> >> 
> >>  FOR_EACH_BB_FN (bb, cfun)
> >>   for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
> >>    {
> >>     gimple *stmt = gsi_stmt (gsi);
> >>     if (!is_gimple_debug (stmt))
> >>      {
> >>       walk_gimple_op (stmt, discover_nonconstant_array_refs_r, &wi);
> >> 
> >> Maybe, this 'walk_gimple_op' is what you mentioned as 'stmt-level
> >> analysis' and the 'pre-walk'.  Is this right?
> >> 
> >> Here, 'discover_nonconstant_array_refs_r' is the callback of
> >> 'walk_gimple_op'.
> >> This callback analyses if an array is accessed through a variant index,
> >> if so, the array must be put into the stack.
> >> 
> >> While it seems 'walk_gimple_op' is not ok for SRA analysis,
> >> because, in the callback, it is hard to analyze an access is
> >> 'read' or 'write' to an struct object. But the 'read/write' info
> >> is needed for SRA.
> >> 
> >> 'walk_stmt_load_store_addr_ops' is another 'walk on stmt ops'.
> >> This 'walk' is not used to analyze SRA access, the primary reason
> >> would be: the load/store/addr parameter of the callback is a
> >> DECL, the 'size' and 'offset' are stripped.
> >> 
> >> Currently, in tree-sra/ipa-sra/expand-sra, when analyzing stmt
> >> for SRA access, stmt code is checked for 'return/assign/call/asm'.
> >> And sub-expressions of these stmt(s) are analyzed.
> >
> > I realize the stmt walks cannot be shared but the per-stmt
> > walk of the SRA analysis should still be done there simply for
> > cache locality reasons (thus compile-time).
> 
> Thanks Richard!
> 
> For the meaning of per-stmt walk, I guess, it may look like below
> fake code:
> 
>      gimple *stmt = gsi_stmt (gsi);
>      if (!is_gimple_debug (stmt))
>       {
>        walk_gimple_op (stmt, discover_nonconstant_array_refs_r, &wi);
>        pre_stmt_analyze_for_sra (stmt);
>        switch (gimple_code (stmt))
>        {
>          case GIMPLE_ASSIGN:
>            ...sra_analyze
>          case GIMPLE_CALL:
>            discover_nonconstant_array_call (as_a <gcall *> (stmt));
>            call_analyze_for_sra (as_a <gasm *> (stmt));
>            ...
>            break
>          ...
> 
> 
> For each stmt, this fake code combines sra_stmt checking and
> force_stack_var checking (we may also combine other stmt check if
> possible later).
> 
> Does may understand correct?  Please point out if any comments, thanks!

Yes, that's good enough.

Richard.


> BR,
> Jeff (Jiufu Guo)
> 
> >
> > Richard.
> >
> >> 
> >> BR,
> >> Jeff (Jiufu Guo)
> >> 
> >> >
> >> > For RTL expansion I think a critical part is to create accesses
> >> > based on the incoming/outgoing RTL which is specified by the ABI.
> >> > As I understand we are optimizing the argument setup code which
> >> > assigns the incoming arguments to either pseudo(s) or the stack
> >> > and thus we get to choose an optimized "mode" for that virtual
> >> > location of the incoming arguments (but we can't alter their
> >> > hardregs/stack assignment obviously).  So when we have an
> >> > incoming register pair we should create an artificial access
> >> > for the pieces those two registers represent.
> >> >
> >> > You seem to do quite some adjustment to the parameter setup
> >> > where I was hoping we get away with simply choosing a different
> >> > mode for the virtual argument representation?
> >> >
> >> > But I'm not too familiar with the innards of parameter/return
> >> > value initial RTL expansion.  I hope somebody else can chime
> >> > in here as well.
> >> >
> >> > Richard.
> >> >
> >> >
> >> >> 
> >> >> BR,
> >> >> Jeff (Jiufu Guo)
> >> >> 
> >> >> -----------------------------
> >> >> diff --git a/gcc/cfgexpand.cc b/gcc/cfgexpand.cc
> >> >> index edf292cfbe9..8c36ad5df79 100644
> >> >> --- a/gcc/cfgexpand.cc
> >> >> +++ b/gcc/cfgexpand.cc
> >> >> @@ -97,6 +97,502 @@ static bool defer_stack_allocation (tree, bool);
> >> >>  
> >> >>  static void record_alignment_for_reg_var (unsigned int);
> >> >>  
> >> >> +extern rtx
> >> >> +expand_shift (enum tree_code, machine_mode, rtx, poly_int64, rtx, int);
> >> >> +
> >> >> +/* For light SRA in expander about paramaters and returns.  */
> >> >> +namespace
> >> >> +{
> >> >> +
> >> >> +struct access
> >> >> +{
> >> >> +  /* Each accessing on the aggragate is about OFFSET/SIZE.  */
> >> >> +  HOST_WIDE_INT offset;
> >> >> +  HOST_WIDE_INT size;
> >> >> +
> >> >> +  bool writing;
> >> >> +
> >> >> +  /* The context expression of this access.  */
> >> >> +  tree expr;
> >> >> +
> >> >> +  /* The rtx for the access: link to incoming/returning register(s).  
> >> >> */
> >> >> +  rtx rtx_val;
> >> >> +};
> >> >> +
> >> >> +typedef struct access *access_p;
> >> >> +
> >> >> +/* Expr (tree) -> Scalarized value (rtx) map.  */
> >> >> +static hash_map<tree, rtx> *expr_rtx_vec;
> >> >> +
> >> >> +/* Base (tree) -> Vector (vec<access_p> *) map.  */
> >> >> +static hash_map<tree, auto_vec<access_p> > *base_access_vec;
> >> >> +
> >> >> +/* Return true if EXPR has interesting access to the sra candidates,
> >> >> +   and created access, return false otherwise.  */
> >> >> +
> >> >> +static struct access *
> >> >> +build_access (tree expr, bool write)
> >> >> +{
> >> >> +  enum tree_code code = TREE_CODE (expr);
> >> >> +  if (code != VAR_DECL && code != PARM_DECL && code != COMPONENT_REF
> >> >> +      && code != ARRAY_REF && code != ARRAY_RANGE_REF)
> >> >> +    return NULL;
> >> >> +
> >> >> +  HOST_WIDE_INT offset, size;
> >> >> +  bool reverse;
> >> >> +  tree base = get_ref_base_and_extent_hwi (expr, &offset, &size, 
> >> >> &reverse);
> >> >> +  if (!base || !DECL_P (base))
> >> >> +    return NULL;
> >> >> +
> >> >> +  vec<access_p> *access_vec = base_access_vec->get (base);
> >> >> +  if (!access_vec)
> >> >> +    return NULL;
> >> >> +
> >> >> +  /* TODO: support reverse. */
> >> >> +  if (reverse || size <= 0 || offset + size > tree_to_shwi (DECL_SIZE 
> >> >> (base)))
> >> >> +    {
> >> >> +      base_access_vec->remove (base);
> >> >> +      return NULL;
> >> >> +    }
> >> >> +
> >> >> +  struct access *access = XNEWVEC (struct access, 1);
> >> >> +
> >> >> +  memset (access, 0, sizeof (struct access));
> >> >> +  access->offset = offset;
> >> >> +  access->size = size;
> >> >> +  access->expr = expr;
> >> >> +  access->writing = write;
> >> >> +  access->rtx_val = NULL_RTX;
> >> >> +
> >> >> +  access_vec->safe_push (access);
> >> >> +
> >> >> +  return access;
> >> >> +}
> >> >> +
> >> >> +/* Callback of walk_stmt_load_store_addr_ops visit_base used to remove
> >> >> +   operands with address taken.  */
> >> >> +
> >> >> +static bool
> >> >> +visit_base (gimple *, tree op, tree, void *)
> >> >> +{
> >> >> +  op = get_base_address (op);
> >> >> +  if (op && DECL_P (op))
> >> >> +    base_access_vec->remove (op);
> >> >> +
> >> >> +  return false;
> >> >> +}
> >> >> +
> >> >> +/* Scan function and look for interesting expressions and create access
> >> >> +   structures for them.  */
> >> >> +
> >> >> +static void
> >> >> +collect_acccesses (void)
> >> >> +{
> >> >> +  basic_block bb;
> >> >> +
> >> >> +  FOR_EACH_BB_FN (bb, cfun)
> >> >> +    {
> >> >> +      for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
> >> >> +          gsi_next (&gsi))
> >> >> +       walk_stmt_load_store_addr_ops (gsi.phi (), NULL, NULL, NULL,
> >> >> +                                      visit_base);
> >> >> +
> >> >> +      for (gimple_stmt_iterator gsi = 
> >> >> gsi_start_nondebug_after_labels_bb (bb);
> >> >> +          !gsi_end_p (gsi); gsi_next_nondebug (&gsi))
> >> >> +       {
> >> >> +         gimple *stmt = gsi_stmt (gsi);
> >> >> +         switch (gimple_code (stmt))
> >> >> +           {
> >> >> +           case GIMPLE_RETURN:
> >> >> +             continue;
> >> >> +           case GIMPLE_ASSIGN:
> >> >> +             if (gimple_assign_single_p (stmt) && !gimple_clobber_p 
> >> >> (stmt))
> >> >> +               {
> >> >> +                 tree rhs = gimple_assign_rhs1 (stmt);
> >> >> +                 tree lhs = gimple_assign_lhs (stmt);
> >> >> +                 bool res_r = build_access (rhs, false);
> >> >> +                 bool res_l = build_access (lhs, true);
> >> >> +                 if (res_l && TREE_CODE (rhs) != CONSTRUCTOR)
> >> >> +                   base_access_vec->remove (get_base_address (lhs));
> >> >> +
> >> >> +                 if (res_l || res_r)
> >> >> +                   continue;
> >> >> +               }
> >> >> +             break;
> >> >> +           default:
> >> >> +             break;
> >> >> +           }
> >> >> +
> >> >> +         walk_stmt_load_store_addr_ops (stmt, NULL, visit_base, 
> >> >> visit_base,
> >> >> +                                        visit_base);
> >> >> +       }
> >> >> +    }
> >> >> +}
> >> >> +
> >> >> +/* Return true if VAR is a candidate for SRA.  */
> >> >> +
> >> >> +static bool
> >> >> +add_sra_candidate (tree var)
> >> >> +{
> >> >> +  tree type = TREE_TYPE (var);
> >> >> +
> >> >> +  if (!AGGREGATE_TYPE_P (type) || !tree_fits_shwi_p (TYPE_SIZE (type))
> >> >> +      || tree_to_shwi (TYPE_SIZE (type)) == 0 || TREE_THIS_VOLATILE 
> >> >> (var)
> >> >> +      || TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT 
> >> >> (va_list_type_node))
> >> >> +    return false;
> >> >> +  gcc_assert (COMPLETE_TYPE_P (type));
> >> >> +
> >> >> +  base_access_vec->get_or_insert (var);
> >> >> +
> >> >> +  return true;
> >> >> +}
> >> >> +
> >> >> +/* Collect the parameter and returns with type which is suitable for
> >> >> + * scalarization.  */
> >> >> +
> >> >> +static bool
> >> >> +collect_sra_candidates (void)
> >> >> +{
> >> >> +  bool ret = false;
> >> >> +
> >> >> +  /* Collect parameters.  */
> >> >> +  for (tree parm = DECL_ARGUMENTS (current_function_decl); parm;
> >> >> +       parm = DECL_CHAIN (parm))
> >> >> +    ret |= add_sra_candidate (parm);
> >> >> +
> >> >> +  /* Collect VARs on returns.  */
> >> >> +  if (DECL_RESULT (current_function_decl))
> >> >> +    {
> >> >> +      edge_iterator ei;
> >> >> +      edge e;
> >> >> +      FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
> >> >> +       if (greturn *r = safe_dyn_cast<greturn *> (*gsi_last_bb 
> >> >> (e->src)))
> >> >> +         {
> >> >> +           tree val = gimple_return_retval (r);
> >> >> +           /* To sclaraized the return, the return value should be only
> >> >> +              writen, except this return stmt.
> >> >> +              Then using 'true(write)' to create the access. */
> >> >> +           if (val && VAR_P (val))
> >> >> +             ret |= add_sra_candidate (val) && build_access (val, 
> >> >> true);
> >> >> +         }
> >> >> +    }
> >> >> +
> >> >> +  return ret;
> >> >> +}
> >> >> +
> >> >> +/* Check if the accesses of BASE are scalarizbale.
> >> >> +   Now, only scalarize the parms only with reading
> >> >> +   or returns only with writing.  */
> >> >> +
> >> >> +static bool
> >> >> +with_scalariable_accesses (vec<access_p> *access_vec, bool is_parm)
> >> >> +{
> >> >> +  if (access_vec->is_empty ())
> >> >> +    return false;
> >> >> +
> >> >> +  for (unsigned int j = 0; j < access_vec->length (); j++)
> >> >> +    {
> >> >> +      struct access *access = (*access_vec)[j];
> >> >> +      /* Writing to a field of parameter. */
> >> >> +      if (is_parm && access->writing)
> >> >> +       return false;
> >> >> +
> >> >> +      /* Writing to a field of parameter. */
> >> >> +      if (!is_parm && !access->writing)
> >> >> +       return false;
> >> >> +    }
> >> >> +
> >> >> +  return true;
> >> >> +}
> >> >> +
> >> >> +static void
> >> >> +prepare_expander_sra ()
> >> >> +{
> >> >> +  if (optimize <= 0)
> >> >> +    return;
> >> >> +
> >> >> +  base_access_vec = new hash_map<tree, auto_vec<access_p> >;
> >> >> +  expr_rtx_vec = new hash_map<tree, rtx>;
> >> >> +
> >> >> +  if (collect_sra_candidates ())
> >> >> +    collect_acccesses ();
> >> >> +}
> >> >> +
> >> >> +static void
> >> >> +free_expander_sra ()
> >> >> +{
> >> >> +  if (optimize <= 0)
> >> >> +    return;
> >> >> +  delete expr_rtx_vec;
> >> >> +  expr_rtx_vec = 0;
> >> >> +  delete base_access_vec;
> >> >> +  base_access_vec = 0;
> >> >> +}
> >> >> +} /* namespace */
> >> >> +
> >> >> +namespace
> >> >> +{
> >> >> +/* Get the register at INDEX from a parallel REGS.  */
> >> >> +
> >> >> +static rtx
> >> >> +extract_parallel_reg (rtx regs, int index)
> >> >> +{
> >> >> +  rtx orig_reg = XEXP (XVECEXP (regs, 0, index), 0);
> >> >> +  if (!HARD_REGISTER_P (orig_reg))
> >> >> +    return orig_reg;
> >> >> +
> >> >> +  /* Reading from param hard reg need to be moved to a temp.  */
> >> >> +  rtx reg = gen_reg_rtx (GET_MODE (orig_reg));
> >> >> +  emit_move_insn (reg, orig_reg);
> >> >> +  return reg;
> >> >> +}
> >> >> +
> >> >> +/* Get IMODE part from REG at OFF_BITS.  */
> >> >> +
> >> >> +static rtx
> >> >> +extract_sub_reg (rtx orig_reg, int off_bits, machine_mode mode)
> >> >> +{
> >> >> +  scalar_int_mode imode;
> >> >> +  if (!int_mode_for_mode (mode).exists (&imode))
> >> >> +    return NULL_RTX;
> >> >> +
> >> >> +  machine_mode orig_mode = GET_MODE (orig_reg);
> >> >> +  gcc_assert (GET_MODE_CLASS (orig_mode) == MODE_INT);
> >> >> +
> >> >> +  poly_uint64 lowpart_off = subreg_lowpart_offset (imode, orig_mode);
> >> >> +  int lowpart_off_bits = lowpart_off.to_constant () * BITS_PER_UNIT;
> >> >> +  int shift_bits;
> >> >> +  if (lowpart_off_bits >= off_bits)
> >> >> +    shift_bits = lowpart_off_bits - off_bits;
> >> >> +  else
> >> >> +    shift_bits = off_bits - lowpart_off_bits;
> >> >> +
> >> >> +  rtx reg = orig_reg;
> >> >> +  if (shift_bits > 0)
> >> >> +    reg = expand_shift (RSHIFT_EXPR, orig_mode, reg, shift_bits, NULL, 
> >> >> 1);
> >> >> +
> >> >> +  rtx subreg = gen_lowpart (imode, reg);
> >> >> +  rtx result = gen_reg_rtx (imode);
> >> >> +  emit_move_insn (result, subreg);
> >> >> +
> >> >> +  if (mode != imode)
> >> >> +    result = gen_lowpart (mode, result);
> >> >> +
> >> >> +  return result;
> >> >> +}
> >> >> +
> >> >> +/* Extract subfields from the REG at START bits to TARGET at OFF,
> >> >> +   BITS parameter is the total number extract bits.  */
> >> >> +
> >> >> +static int
> >> >> +extract_fields_from_reg (rtx reg, int bits, int start, rtx *target,
> >> >> +                        HOST_WIDE_INT off)
> >> >> +{
> >> >> +  machine_mode mode_aux[] = {SImode, HImode, QImode};
> >> >> +  int margins = sizeof (mode_aux) / sizeof (mode_aux[0]);
> >> >> +  HOST_WIDE_INT off_bits = start;
> >> >> +  rtx *p = target;
> >> >> +  for (int n = 0; n < margins; n++)
> >> >> +    {
> >> >> +      machine_mode mode = mode_aux[n];
> >> >> +      HOST_WIDE_INT bitsize = GET_MODE_BITSIZE (mode).to_constant ();
> >> >> +      if (bits < bitsize)
> >> >> +       continue;
> >> >> +
> >> >> +      rtx subreg = extract_sub_reg (reg, off_bits, mode);
> >> >> +      *p++ = gen_rtx_EXPR_LIST (mode, subreg, GEN_INT (off));
> >> >> +      off += bitsize / BITS_PER_UNIT;
> >> >> +      off_bits += bitsize;
> >> >> +      bits -= bitsize;
> >> >> +    }
> >> >> +
> >> >> +  return p - target;
> >> >> +}
> >> >> +} /* namespace */
> >> >> +
> >> >> +/* Check If there is an sra access for the expr.
> >> >> +   Return the correspond scalar sym for the access. */
> >> >> +
> >> >> +rtx
> >> >> +get_scalar_rtx_for_aggregate_expr (tree expr)
> >> >> +{
> >> >> +  if (!expr_rtx_vec)
> >> >> +    return NULL_RTX;
> >> >> +  rtx *val = expr_rtx_vec->get (expr);
> >> >> +  return val ? *val : NULL_RTX;
> >> >> +}
> >> >> +
> >> >> +/* Compute/Set RTX registers for those accesses on BASE.  */
> >> >> +
> >> >> +void
> >> >> +set_scalar_rtx_for_aggregate_access (tree base, rtx regs)
> >> >> +{
> >> >> +  if (!base_access_vec)
> >> >> +    return;
> >> >> +  vec<access_p> *access_vec = base_access_vec->get (base);
> >> >> +  if (!access_vec)
> >> >> +    return;
> >> >> +  bool is_parm = TREE_CODE (base) == PARM_DECL;
> >> >> +  if (!with_scalariable_accesses (access_vec, is_parm))
> >> >> +    return;
> >> >> +
> >> >> +  /* Go through each access, compute corresponding rtx(regs or subregs)
> >> >> +     for the expression.  */
> >> >> +  int n = access_vec->length ();
> >> >> +  int cur_access_index = 0;
> >> >> +  for (; cur_access_index < n; cur_access_index++)
> >> >> +    {
> >> >> +      access_p acc = (*access_vec)[cur_access_index];
> >> >> +      machine_mode expr_mode = TYPE_MODE (TREE_TYPE (acc->expr));
> >> >> +
> >> >> +      /* mode of mult registers. */
> >> >> +      if (expr_mode != BLKmode
> >> >> +         && known_gt (acc->size, GET_MODE_BITSIZE (word_mode)))
> >> >> +       break;
> >> >> +
> >> >> +      /* Compute the position of the access in the whole parallel rtx. 
> >> >>  */
> >> >> +      int start_index = -1;
> >> >> +      int end_index = -1;
> >> >> +      HOST_WIDE_INT left_bits = 0;
> >> >> +      HOST_WIDE_INT right_bits = 0;
> >> >> +      int cur_index = XEXP (XVECEXP (regs, 0, 0), 0) ? 0 : 1;
> >> >> +      for (; cur_index < XVECLEN (regs, 0); cur_index++)
> >> >> +       {
> >> >> +         rtx slot = XVECEXP (regs, 0, cur_index);
> >> >> +         HOST_WIDE_INT off = UINTVAL (XEXP (slot, 1)) * BITS_PER_UNIT;
> >> >> +         machine_mode mode = GET_MODE (XEXP (slot, 0));
> >> >> +         HOST_WIDE_INT size = GET_MODE_BITSIZE (mode).to_constant ();
> >> >> +         if (off <= acc->offset && off + size > acc->offset)
> >> >> +           {
> >> >> +             start_index = cur_index;
> >> >> +             left_bits = acc->offset - off;
> >> >> +           }
> >> >> +         if (off + size >= acc->offset + acc->size)
> >> >> +           {
> >> >> +             end_index = cur_index;
> >> >> +             right_bits = off + size - (acc->offset + acc->size);
> >> >> +             break;
> >> >> +           }
> >> >> +       }
> >> >> +      /* Invalid access possition: padding or outof bound.  */
> >> >> +      if (start_index < 0 || end_index < 0)
> >> >> +       break;
> >> >> +
> >> >> +      /* Need a parallel for possible multi-registers. */
> >> >> +      if (expr_mode == BLKmode || end_index > start_index)
> >> >> +       {
> >> >> +         /* More possible space for SI, HI, QI.  */
> >> >> +         machine_mode mode_aux[] = {SImode, HImode, QImode};
> >> >> +         int margins = sizeof (mode_aux) / sizeof (mode_aux[0]);
> >> >> +         int extra = (right_bits ? margins : 0) + (left_bits ? margins 
> >> >> : 0);
> >> >> +         int num_words = end_index - start_index + 1;
> >> >> +         num_words -= (right_bits ? 1 : 0);
> >> >> +         num_words -= (left_bits ? 1 : 0);
> >> >> +         rtx *tmps = XALLOCAVEC (rtx, num_words + extra);
> >> >> +
> >> >> +         int pos = 0;
> >> >> +         /* There are extra fields from the left part of the start 
> >> >> reg.  */
> >> >> +         if (left_bits)
> >> >> +           {
> >> >> +             gcc_assert (!acc->writing);
> >> >> +             gcc_assert ((left_bits % BITS_PER_UNIT) == 0);
> >> >> +
> >> >> +             rtx reg = XEXP (XVECEXP (regs, 0, start_index), 0);
> >> >> +             machine_mode mode = GET_MODE (reg);
> >> >> +             int reg_size = GET_MODE_BITSIZE (mode).to_constant ();
> >> >> +             int bits = reg_size - left_bits;
> >> >> +             pos = extract_fields_from_reg (reg, bits, left_bits, 
> >> >> tmps, 0);
> >> >> +           }
> >> >> +
> >> >> +         HOST_WIDE_INT start;
> >> >> +         start = UINTVAL (XEXP (XVECEXP (regs, 0, start_index), 1));
> >> >> +         start -= left_bits / BITS_PER_UNIT;
> >> >> +         /* Extract whole registers.  */
> >> >> +         for (; pos < num_words; pos++)
> >> >> +           {
> >> >> +             int index = start_index + pos;
> >> >> +             rtx reg = extract_parallel_reg (regs, index);
> >> >> +             machine_mode mode = GET_MODE (reg);
> >> >> +             HOST_WIDE_INT off;
> >> >> +             off = UINTVAL (XEXP (XVECEXP (regs, 0, index), 1)) - 
> >> >> start;
> >> >> +             tmps[pos] = gen_rtx_EXPR_LIST (mode, reg, GEN_INT (off));
> >> >> +           }
> >> >> +
> >> >> +         /* No more fields.   */
> >> >> +         if (right_bits == 0)
> >> >> +           {
> >> >> +             rtx reg = gen_rtx_PARALLEL (expr_mode, gen_rtvec_v (pos, 
> >> >> tmps));
> >> >> +             acc->rtx_val = reg;
> >> >> +             continue;
> >> >> +           }
> >> >> +
> >> >> +         /* There are extra fields from the part of register.   */
> >> >> +         gcc_assert (!acc->writing);
> >> >> +         gcc_assert ((right_bits % BITS_PER_UNIT) == 0);
> >> >> +
> >> >> +         HOST_WIDE_INT off;
> >> >> +         off = UINTVAL (XEXP (XVECEXP (regs, 0, end_index), 1)) - 
> >> >> start;
> >> >> +         rtx reg = XEXP (XVECEXP (regs, 0, end_index), 0);
> >> >> +         machine_mode mode = GET_MODE (reg);
> >> >> +         int reg_size = GET_MODE_BITSIZE (mode).to_constant ();
> >> >> +         int bits = reg_size - right_bits;
> >> >> +         pos += extract_fields_from_reg (reg, bits, 0, tmps + pos, 
> >> >> off);
> >> >> +
> >> >> +         /* Currently, PARALLELs with register elements for 
> >> >> param/returns
> >> >> +            are using BLKmode.  */
> >> >> +         acc->rtx_val = gen_rtx_PARALLEL (expr_mode, gen_rtvec_v (pos, 
> >> >> tmps));
> >> >> +         continue;
> >> >> +       }
> >> >> +
> >> >> +      /* Just need one reg for the correspond access.  */
> >> >> +      if (end_index == start_index && left_bits == 0 && right_bits == 
> >> >> 0)
> >> >> +       {
> >> >> +         rtx reg = extract_parallel_reg (regs, start_index);
> >> >> +         if (GET_MODE (reg) != expr_mode)
> >> >> +           reg = gen_lowpart (expr_mode, reg);
> >> >> +
> >> >> +         acc->rtx_val = reg;
> >> >> +         continue;
> >> >> +       }
> >> >> +
> >> >> +      /* Need to shift to extract a part reg for the access.  */
> >> >> +      if (!acc->writing && end_index == start_index)
> >> >> +       {
> >> >> +         rtx orig_reg = XEXP (XVECEXP (regs, 0, start_index), 0);
> >> >> +         acc->rtx_val = extract_sub_reg (orig_reg, left_bits, 
> >> >> expr_mode);
> >> >> +         if (acc->rtx_val)
> >> >> +           continue;
> >> >> +       }
> >> >> +
> >> >> +      break;
> >> >> +    }
> >> >> +
> >> >> +  /* If all access expr(s) are not scalarized,
> >> >> +     bind/map all expr(tree) to sclarized rtx.  */
> >> >> +  if (cur_access_index == n)
> >> >> +    for (int j = 0; j < n; j++)
> >> >> +      {
> >> >> +       access_p access = (*access_vec)[j];
> >> >> +       expr_rtx_vec->put (access->expr, access->rtx_val);
> >> >> +      }
> >> >> +}
> >> >> +
> >> >> +void
> >> >> +set_scalar_rtx_for_returns ()
> >> >> +{
> >> >> +  tree res = DECL_RESULT (current_function_decl);
> >> >> +  gcc_assert (res);
> >> >> +  edge_iterator ei;
> >> >> +  edge e;
> >> >> +  FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
> >> >> +    if (greturn *r = safe_dyn_cast<greturn *> (*gsi_last_bb (e->src)))
> >> >> +      {
> >> >> +       tree val = gimple_return_retval (r);
> >> >> +       if (val && VAR_P (val))
> >> >> +         set_scalar_rtx_for_aggregate_access (val, DECL_RTL (res));
> >> >> +      }
> >> >> +}
> >> >> +
> >> >>  /* Return an expression tree corresponding to the RHS of GIMPLE
> >> >>     statement STMT.  */
> >> >>  
> >> >> @@ -3778,7 +4274,8 @@ expand_return (tree retval)
> >> >>  
> >> >>    /* If we are returning the RESULT_DECL, then the value has already
> >> >>       been stored into it, so we don't have to do anything special.  */
> >> >> -  if (TREE_CODE (retval_rhs) == RESULT_DECL)
> >> >> +  if (TREE_CODE (retval_rhs) == RESULT_DECL
> >> >> +      || get_scalar_rtx_for_aggregate_expr (retval_rhs))
> >> >>      expand_value_return (result_rtl);
> >> >>  
> >> >>    /* If the result is an aggregate that is being returned in one (or 
> >> >> more)
> >> >> @@ -4422,6 +4919,9 @@ expand_debug_expr (tree exp)
> >> >>    int unsignedp = TYPE_UNSIGNED (TREE_TYPE (exp));
> >> >>    addr_space_t as;
> >> >>    scalar_int_mode op0_mode, op1_mode, addr_mode;
> >> >> +  rtx x = get_scalar_rtx_for_aggregate_expr (exp);
> >> >> +  if (x)
> >> >> +    return NULL_RTX;/* optimized out.  */
> >> >>  
> >> >>    switch (TREE_CODE_CLASS (TREE_CODE (exp)))
> >> >>      {
> >> >> @@ -6620,6 +7120,8 @@ pass_expand::execute (function *fun)
> >> >>             avoid_deep_ter_for_debug (gsi_stmt (gsi), 0);
> >> >>      }
> >> >>  
> >> >> +  prepare_expander_sra ();
> >> >> +
> >> >>    /* Mark arrays indexed with non-constant indices with 
> >> >> TREE_ADDRESSABLE.  */
> >> >>    auto_bitmap forced_stack_vars;
> >> >>    discover_nonconstant_array_refs (forced_stack_vars);
> >> >> @@ -7052,6 +7554,7 @@ pass_expand::execute (function *fun)
> >> >>        loop_optimizer_finalize ();
> >> >>      }
> >> >>  
> >> >> +  free_expander_sra ();
> >> >>    timevar_pop (TV_POST_EXPAND);
> >> >>  
> >> >>    return 0;
> >> >> diff --git a/gcc/expr.cc b/gcc/expr.cc
> >> >> index fff09dc9951..d487fe3b53b 100644
> >> >> --- a/gcc/expr.cc
> >> >> +++ b/gcc/expr.cc
> >> >> @@ -100,6 +100,7 @@ static void do_tablejump (rtx, machine_mode, rtx, 
> >> >> rtx, rtx,
> >> >>  static rtx const_vector_from_tree (tree);
> >> >>  static tree tree_expr_size (const_tree);
> >> >>  static void convert_mode_scalar (rtx, rtx, int);
> >> >> +rtx get_scalar_rtx_for_aggregate_expr (tree);
> >> >>  
> >> >>  
> >> >>  /* This is run to set up which modes can be used
> >> >> @@ -5623,11 +5624,12 @@ expand_assignment (tree to, tree from, bool 
> >> >> nontemporal)
> >> >>       Assignment of an array element at a constant index, and 
> >> >> assignment of
> >> >>       an array element in an unaligned packed structure field, has the 
> >> >> same
> >> >>       problem.  Same for (partially) storing into a non-memory object.  
> >> >> */
> >> >> -  if (handled_component_p (to)
> >> >> -      || (TREE_CODE (to) == MEM_REF
> >> >> -         && (REF_REVERSE_STORAGE_ORDER (to)
> >> >> -             || mem_ref_refers_to_non_mem_p (to)))
> >> >> -      || TREE_CODE (TREE_TYPE (to)) == ARRAY_TYPE)
> >> >> +  if (!get_scalar_rtx_for_aggregate_expr (to)
> >> >> +      && (handled_component_p (to)
> >> >> +         || (TREE_CODE (to) == MEM_REF
> >> >> +             && (REF_REVERSE_STORAGE_ORDER (to)
> >> >> +                 || mem_ref_refers_to_non_mem_p (to)))
> >> >> +         || TREE_CODE (TREE_TYPE (to)) == ARRAY_TYPE))
> >> >>      {
> >> >>        machine_mode mode1;
> >> >>        poly_int64 bitsize, bitpos;
> >> >> @@ -9011,6 +9013,9 @@ expand_expr_real (tree exp, rtx target, 
> >> >> machine_mode tmode,
> >> >>        ret = CONST0_RTX (tmode);
> >> >>        return ret ? ret : const0_rtx;
> >> >>      }
> >> >> +  rtx x = get_scalar_rtx_for_aggregate_expr (exp);
> >> >> +  if (x)
> >> >> +    return x;
> >> >>  
> >> >>    ret = expand_expr_real_1 (exp, target, tmode, modifier, alt_rtl,
> >> >>                             inner_reference_p);
> >> >> diff --git a/gcc/function.cc b/gcc/function.cc
> >> >> index dd2c1136e07..7fe927bd36b 100644
> >> >> --- a/gcc/function.cc
> >> >> +++ b/gcc/function.cc
> >> >> @@ -2740,6 +2740,9 @@ assign_parm_find_stack_rtl (tree parm, struct 
> >> >> assign_parm_data_one *data)
> >> >>    data->stack_parm = stack_parm;
> >> >>  }
> >> >>  
> >> >> +extern void set_scalar_rtx_for_aggregate_access (tree, rtx);
> >> >> +extern void set_scalar_rtx_for_returns ();
> >> >> +
> >> >>  /* A subroutine of assign_parms.  Adjust DATA->ENTRY_RTL such that it's
> >> >>     always valid and contiguous.  */
> >> >>  
> >> >> @@ -3115,8 +3118,24 @@ assign_parm_setup_block (struct 
> >> >> assign_parm_data_all *all,
> >> >>           emit_move_insn (mem, entry_parm);
> >> >>         }
> >> >>        else
> >> >> -       move_block_from_reg (REGNO (entry_parm), mem,
> >> >> -                            size_stored / UNITS_PER_WORD);
> >> >> +       {
> >> >> +         int regno = REGNO (entry_parm);
> >> >> +         int nregs = size_stored / UNITS_PER_WORD;
> >> >> +         move_block_from_reg (regno, mem, nregs);
> >> >> +
> >> >> +         rtx *tmps = XALLOCAVEC (rtx, nregs);
> >> >> +         machine_mode mode = word_mode;
> >> >> +         HOST_WIDE_INT word_size = GET_MODE_SIZE (mode).to_constant ();
> >> >> +         for (int i = 0; i < nregs; i++)
> >> >> +           {
> >> >> +             rtx reg = gen_rtx_REG (mode, regno + i);
> >> >> +             rtx off = GEN_INT (word_size * i);
> >> >> +             tmps[i] = gen_rtx_EXPR_LIST (VOIDmode, reg, off);
> >> >> +           }
> >> >> +
> >> >> +         rtx regs = gen_rtx_PARALLEL (BLKmode, gen_rtvec_v (nregs, 
> >> >> tmps));
> >> >> +         set_scalar_rtx_for_aggregate_access (parm, regs);
> >> >> +       }
> >> >>      }
> >> >>    else if (data->stack_parm == 0 && !TYPE_EMPTY_P (data->arg.type))
> >> >>      {
> >> >> @@ -3716,6 +3735,10 @@ assign_parms (tree fndecl)
> >> >>        else
> >> >>         set_decl_incoming_rtl (parm, data.entry_parm, false);
> >> >>  
> >> >> +      rtx incoming = DECL_INCOMING_RTL (parm);
> >> >> +      if (GET_CODE (incoming) == PARALLEL)
> >> >> +       set_scalar_rtx_for_aggregate_access (parm, incoming);
> >> >> +
> >> >>        assign_parm_adjust_stack_rtl (&data);
> >> >>  
> >> >>        if (assign_parm_setup_block_p (&data))
> >> >> @@ -5136,6 +5159,7 @@ expand_function_start (tree subr)
> >> >>             {
> >> >>               gcc_assert (GET_CODE (hard_reg) == PARALLEL);
> >> >>               set_parm_rtl (res, gen_group_rtx (hard_reg));
> >> >> +             set_scalar_rtx_for_returns ();
> >> >>             }
> >> >>         }
> >> >>  
> >> >> diff --git a/gcc/testsuite/g++.target/powerpc/pr102024.C 
> >> >> b/gcc/testsuite/g++.target/powerpc/pr102024.C
> >> >> index 769585052b5..c8995cae707 100644
> >> >> --- a/gcc/testsuite/g++.target/powerpc/pr102024.C
> >> >> +++ b/gcc/testsuite/g++.target/powerpc/pr102024.C
> >> >> @@ -5,7 +5,7 @@
> >> >>  // Test that a zero-width bit field in an otherwise homogeneous 
> >> >> aggregate
> >> >>  // generates a psabi warning and passes arguments in GPRs.
> >> >>  
> >> >> -// { dg-final { scan-assembler-times {\mstd\M} 4 } }
> >> >> +// { dg-final { scan-assembler-times {\mmtvsrd\M} 4 } }
> >> >>  
> >> >>  struct a_thing
> >> >>  {
> >> >> diff --git a/gcc/testsuite/gcc.target/powerpc/pr108073.c 
> >> >> b/gcc/testsuite/gcc.target/powerpc/pr108073.c
> >> >> new file mode 100644
> >> >> index 00000000000..7dd1a4a326a
> >> >> --- /dev/null
> >> >> +++ b/gcc/testsuite/gcc.target/powerpc/pr108073.c
> >> >> @@ -0,0 +1,29 @@
> >> >> +/* { dg-do run } */
> >> >> +/* { dg-options "-O2 -save-temps" } */
> >> >> +
> >> >> +typedef struct DF {double a[4]; short s1; short s2; short s3; short 
> >> >> s4; } DF;
> >> >> +typedef struct SF {float a[4]; int i1; int i2; } SF;
> >> >> +
> >> >> +/* { dg-final { scan-assembler-times {\mmtvsrd\M} 3 {target { 
> >> >> has_arch_ppc64 && has_arch_pwr8 } } } } */
> >> >> +/* { dg-final { scan-assembler-not {\mlwz\M} {target { has_arch_ppc64 
> >> >> && has_arch_pwr8 } } } } */
> >> >> +/* { dg-final { scan-assembler-not {\mlhz\M} {target { has_arch_ppc64 
> >> >> && has_arch_pwr8 } } } } */
> >> >> +short  __attribute__ ((noipa)) foo_hi (DF a, int flag){if (flag == 
> >> >> 2)return a.s2+a.s3;return 0;}
> >> >> +int  __attribute__ ((noipa)) foo_si (SF a, int flag){if (flag == 
> >> >> 2)return a.i2+a.i1;return 0;}
> >> >> +double __attribute__ ((noipa)) foo_df (DF arg, int flag){if (flag == 
> >> >> 2)return arg.a[3];else return 0.0;}
> >> >> +float  __attribute__ ((noipa)) foo_sf (SF arg, int flag){if (flag == 
> >> >> 2)return arg.a[2]; return 0;}
> >> >> +float  __attribute__ ((noipa)) foo_sf1 (SF arg, int flag){if (flag == 
> >> >> 2)return arg.a[1];return 0;}
> >> >> +
> >> >> +DF gdf = {{1.0,2.0,3.0,4.0}, 1, 2, 3, 4};
> >> >> +SF gsf = {{1.0f,2.0f,3.0f,4.0f}, 1, 2};
> >> >> +
> >> >> +int main()
> >> >> +{
> >> >> +  if (!(foo_hi (gdf, 2) == 5 && foo_si (gsf, 2) == 3 && foo_df (gdf, 
> >> >> 2) == 4.0
> >> >> +       && foo_sf (gsf, 2) == 3.0 && foo_sf1 (gsf, 2) == 2.0))
> >> >> +    __builtin_abort ();
> >> >> +  if (!(foo_hi (gdf, 1) == 0 && foo_si (gsf, 1) == 0 && foo_df (gdf, 
> >> >> 1) == 0
> >> >> +       && foo_sf (gsf, 1) == 0 && foo_sf1 (gsf, 1) == 0))
> >> >> +    __builtin_abort ();
> >> >> +  return 0;
> >> >> +}
> >> >> +
> >> >> diff --git a/gcc/testsuite/gcc.target/powerpc/pr65421-1.c 
> >> >> b/gcc/testsuite/gcc.target/powerpc/pr65421-1.c
> >> >> new file mode 100644
> >> >> index 00000000000..4e1f87f7939
> >> >> --- /dev/null
> >> >> +++ b/gcc/testsuite/gcc.target/powerpc/pr65421-1.c
> >> >> @@ -0,0 +1,6 @@
> >> >> +/* PR target/65421 */
> >> >> +/* { dg-options "-O2" } */
> >> >> +
> >> >> +typedef struct LARGE {double a[4]; int arr[32];} LARGE;
> >> >> +LARGE foo (LARGE a){return a;}
> >> >> +/* { dg-final { scan-assembler-times {\mmemcpy\M} 1 } } */
> >> >> diff --git a/gcc/testsuite/gcc.target/powerpc/pr65421-2.c 
> >> >> b/gcc/testsuite/gcc.target/powerpc/pr65421-2.c
> >> >> new file mode 100644
> >> >> index 00000000000..8a8e1a0e996
> >> >> --- /dev/null
> >> >> +++ b/gcc/testsuite/gcc.target/powerpc/pr65421-2.c
> >> >> @@ -0,0 +1,32 @@
> >> >> +/* PR target/65421 */
> >> >> +/* { dg-options "-O2" } */
> >> >> +/* { dg-require-effective-target powerpc_elfv2 } */
> >> >> +/* { dg-require-effective-target has_arch_ppc64 } */
> >> >> +
> >> >> +typedef struct FLOATS
> >> >> +{
> >> >> +  double a[3];
> >> >> +} FLOATS;
> >> >> +
> >> >> +/* 3 lfd after returns also optimized */
> >> >> +/* FLOATS ret_arg_pt (FLOATS *a){return *a;} */
> >> >> +
> >> >> +/* 3 stfd */
> >> >> +void st_arg (FLOATS a, FLOATS *p) {*p = a;}
> >> >> +/* { dg-final { scan-assembler-times {\mstfd\M} 3 } } */
> >> >> +
> >> >> +/* blr */
> >> >> +FLOATS ret_arg (FLOATS a) {return a;}
> >> >> +
> >> >> +typedef struct MIX
> >> >> +{
> >> >> +  double a[2];
> >> >> +  long l;
> >> >> +} MIX;
> >> >> +
> >> >> +/* std 3 param regs to return slot */
> >> >> +MIX ret_arg1 (MIX a) {return a;}
> >> >> +/* { dg-final { scan-assembler-times {\mstd\M} 3 } } */
> >> >> +
> >> >> +/* count insns */
> >> >> +/* { dg-final { scan-assembler-times {(?n)^\s+[a-z]} 9 } } */
> >> >> 
> >> >> >
> >> >> > Richard.
> >> >> >
> >> >> >> 
> >> >> >> BR,
> >> >> >> Jeff (Jiufu Guo)
> >> >> >> 
> >> >> >> 
> >> >> >> Jiufu Guo via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> >> >> >> 
> >> >> >> > Hi Martin,
> >> >> >> >
> >> >> >> > Jiufu Guo via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> >> >> >> >
> >> >> >> >> Hi,
> >> >> >> >>
> >> >> >> >> Martin Jambor <mjam...@suse.cz> writes:
> >> >> >> >>
> >> >> >> >>> Hi,
> >> >> >> >>>
> >> >> >> >>> On Tue, May 30 2023, Richard Biener wrote:
> >> >> >> >>>> On Mon, 29 May 2023, Jiufu Guo wrote:
> >> >> >> >>>>
> >> >> >> >>>>> Hi,
> >> >> >> >>>>> 
> >> >> >> >>>>> Previously, I was investigating some struct parameters and 
> >> >> >> >>>>> returns related
> >> >> >> >>>>> PRs 69143/65421/108073.
> >> >> >> >>>>> 
> >> >> >> >>>>> Investigating the issues case by case, and drafting patches 
> >> >> >> >>>>> for each of
> >> >> >> >>>>> them one by one. This would help us to enhance code 
> >> >> >> >>>>> incrementally.
> >> >> >> >>>>> While, this way, patches would interact with each other and 
> >> >> >> >>>>> implement
> >> >> >> >>>>> different codes for similar issues (because of the different 
> >> >> >> >>>>> paths in
> >> >> >> >>>>> gimple/rtl).  We may have a common fix for those issues.
> >> >> >> >>>>> 
> >> >> >> >>>>> We know a few other related PRs(such as meta-bug PR101926) 
> >> >> >> >>>>> exist. For those
> >> >> >> >>>>> PRs in different targets with different symptoms (and also 
> >> >> >> >>>>> different root
> >> >> >> >>>>> cause), I would expect a method could help some of them, but 
> >> >> >> >>>>> it may
> >> >> >> >>>>> be hard to handle all of them in one fix.
> >> >> >> >>>>> 
> >> >> >> >>>>> With investigation and check discussion for the issues, I 
> >> >> >> >>>>> remember a
> >> >> >> >>>>> suggestion from Richard: it would be nice to perform some 
> >> >> >> >>>>> SRA-like analysis
> >> >> >> >>>>> for the accesses on the structs (parameter/returns).
> >> >> >> >>>>> https://gcc.gnu.org/pipermail/gcc-patches/2022-November/605117.html
> >> >> >> >>>>> This may be a 'fairly common method' for those issues. With 
> >> >> >> >>>>> this idea,
> >> >> >> >>>>> I drafted a patch as below in this mail.
> >> >> >> >>>>> 
> >> >> >> >>>>> I also thought about directly using tree-sra.cc, e.g. enhance 
> >> >> >> >>>>> it and rerun it
> >> >> >> >>>>> at the end of GIMPLE passes. While since some issues are 
> >> >> >> >>>>> introduced inside
> >> >> >> >>>>> the expander, so below patch also co-works with other parts of 
> >> >> >> >>>>> the expander.
> >> >> >> >>>>> And since we already have tree-sra in gimple pass, we only 
> >> >> >> >>>>> need to take more
> >> >> >> >>>>> care on parameter and return in this patch: other decls could 
> >> >> >> >>>>> be handled
> >> >> >> >>>>> well in tree-sra.
> >> >> >> >>>>> 
> >> >> >> >>>>> The steps of this patch are:
> >> >> >> >>>>> 1. Collect struct type parameters and returns, and then scan 
> >> >> >> >>>>> the function to
> >> >> >> >>>>> get the accesses on them. And figure out the accesses which 
> >> >> >> >>>>> would be profitable
> >> >> >> >>>>> to be scalarized (using registers of the parameter/return ). 
> >> >> >> >>>>> Now, reading on
> >> >> >> >>>>> parameter and writing on returns are checked in the current 
> >> >> >> >>>>> patch.
> >> >> >> >>>>> 2. When/after the scalar registers are determined/expanded for 
> >> >> >> >>>>> the return or
> >> >> >> >>>>> parameters, compute the corresponding scalar register(s) for 
> >> >> >> >>>>> each accesses of
> >> >> >> >>>>> the return/parameter, and prepare the scalar RTLs for those 
> >> >> >> >>>>> accesses.
> >> >> >> >>>>> 3. When using/expanding the accesses expression, leverage the 
> >> >> >> >>>>> computed/prepared
> >> >> >> >>>>> scalars directly.
> >> >> >> >>>>> 
> >> >> >> >>>>> This patch is tested on ppc64 both LE and BE.
> >> >> >> >>>>> To continue, I would ask for comments and suggestions first. 
> >> >> >> >>>>> And then I would
> >> >> >> >>>>> update/enhance accordingly.  Thanks in advance!
> >> >> >> >>>>
> >> >> >> >>>> Thanks for working on this - the description above sounds 
> >> >> >> >>>> exactly like
> >> >> >> >>>> what should be done.
> >> >> >> >>>>
> >> >> >> >>>> Now - I'd like the code to re-use the access tree data 
> >> >> >> >>>> structure from
> >> >> >> >>>> SRA plus at least the worker creating the accesses from a stmt.
> >> >> >> >>>
> >> >> >> >
> >> >> >> > I'm thinking about which part of the code can be re-used from
> >> >> >> > ipa-sra and tree-sra.
> >> >> >> > It seems there are some similar concepts between them:
> >> >> >> > "access with offset/size", "collect and check candidates",
> >> >> >> > "analyze accesses"...
> >> >> >> >
> >> >> >> > While because the purposes are different, the logic and behavior
> >> >> >> > between them (ipa-sra, tree-sra, and expander-sra) are different,
> >> >> >> > even for similar concepts.
> >> >> >> >
> >> >> >> > The same behavior and similar concept may be reusable. Below list
> >> >> >> > may be part of them.
> >> >> >> > *. allocate and maintain access
> >> >> >> >    basic access structure: offset, size, reverse
> >> >> >> > *. type or expr checking
> >> >> >> > *. disqualify
> >> >> >> > *. scan and build expr access
> >> >> >> > *. scan and walk stmts (return/assign/call/asm)
> >> >> >> > *. collect candidates
> >> >> >> > *. initialize/deinitialize
> >> >> >> > *. access dump
> >> >> >> >
> >> >> >> > There are different behaviors for a similar concept.
> >> >> >> > For examples:
> >> >> >> > *. Access has grg/queues in tree-sra, access has nonarg in ipa-sra,
> >> >> >> > and expander-sra does not check access's child/sibling yet.
> >> >> >> > *. for same stmt(assign/call), different sra checks different 
> >> >> >> > logic.
> >> >> >> > *. candidates have different checking logic: ipa-sra checks more 
> >> >> >> > stuff.
> >> >> >> >
> >> >> >> > Is this align with your thoughts?  Thanks for comments!
> >> >> >> >
> >> >> >> > BR,
> >> >> >> > Jeff (Jiufu Guo)
> >> >> >> >
> >> >> >> >> Thanks Martin for your reply and thanks for your time!
> >> >> >> >>
> >> >> >> >>> I have had a first look at the patch but still need to look into 
> >> >> >> >>> it more
> >> >> >> >>> to understand how it uses the information it gathers.
> >> >> >> >>>
> >> >> >> >>> My plan is to make the access-tree infrastructure of IPA-SRA more
> >> >> >> >>> generic and hopefully usable even for this purpose, rather than 
> >> >> >> >>> the one
> >> >> >> >>> in tree-sra.cc.  But that really builds a tree of accesses, 
> >> >> >> >>> bailing out
> >> >> >> >>> on any partial overlaps, for example, which may not be the right 
> >> >> >> >>> thing
> >> >> >> >>> here since I don't see any tree-building here.
> >> >> >> >>
> >> >> >> >> Yeap, both in tree-sra and ipa-sra, there are concepts about
> >> >> >> >> "access" and "scan functions/stmts". In this light-sra, these 
> >> >> >> >> concepts
> >> >> >> >> are also used. And you may notice that ipa-sra and tree-sra have 
> >> >> >> >> more
> >> >> >> >> logic than the current 'light-expand-sra'.
> >> >> >> >>
> >> >> >> >> Currently, the 'light-expand-sra' just takes care few things: 
> >> >> >> >> reading
> >> >> >> >> from parameter, writing to returns, and disabling sra if 
> >> >> >> >> address-taken.
> >> >> >> >> As you notice, now the "access" in this patch is not in a 
> >> >> >> >> 'tree-struct',
> >> >> >> >> it is just a 'flat' (or say map & vector). And overlaps between
> >> >> >> >> accesses are not checked because they are all just reading (for 
> >> >> >> >> parm).
> >> >> >> >>
> >> >> >> >> When we take care of more stuff: passing to call argument, occur 
> >> >> >> >> in
> >> >> >> >> memory assignment, occur in line asm... This light-expander-sra 
> >> >> >> >> would be
> >> >> >> >> more and more like tee-sra and ipa-sra. And it would be good to 
> >> >> >> >> leverage
> >> >> >> >> more capabilities from tree-sra and ipa-sra. So, I agree that it 
> >> >> >> >> would be
> >> >> >> >> a great idea to share and reuse the same struct.
> >> >> >> >>
> >> >> >> >>> But I still need to
> >> >> >> >>> properly read set_scalar_rtx_for_aggregate_access function in 
> >> >> >> >>> the patch,
> >> >> >> >>> which I plan to do next week.
> >> >> >> >>
> >> >> >> >> set_scalar_rtx_for_aggregate_access is another key part of this 
> >> >> >> >> patch.
> >> >> >> >> Different from tree-sra/ipa-sra (which creates new scalars SSA 
> >> >> >> >> for each
> >> >> >> >> access), this patch invokes "set_scalar_rtx_for_aggregate_access" 
> >> >> >> >> to
> >> >> >> >> create an rtx expression for each access. Now, this part may not 
> >> >> >> >> common
> >> >> >> >> with tree-sra and ipa-sra.
> >> >> >> >>
> >> >> >> >> This function is invoked for each parameter if the parameter is
> >> >> >> >> aggregate type and passed via registers.
> >> >> >> >> For each access about this parameter, the function creates an rtx
> >> >> >> >> according to the offset/size/mode of the access. The created rtx 
> >> >> >> >> maybe:
> >> >> >> >> 1. one rtx pseudo corresponds to an incoming reg,
> >> >> >> >> 2. one rtx pseudo which is assigned by a part of incoming reg 
> >> >> >> >> after
> >> >> >> >> shift and mode adjust,
> >> >> >> >> 3. a parallel rtx contains a few rtx pseudos corresponding to the
> >> >> >> >> incoming registers.
> >> >> >> >> For return, only 1 and 3 are ok.
> >> >> >> >>
> >> >> >> >> BR,
> >> >> >> >> Jeff (Jiufu Guo)
> >> >> >> >>
> >> >> >> >>>
> >> >> >> >>> Thanks,
> >> >> >> >>>
> >> >> >> >>> Martin
> >> >> >> >>>
> >> >> >> >>>>
> >> >> >> >>>> The RTL expansion code already does a sweep over stmts in
> >> >> >> >>>> discover_nonconstant_array_refs which makes sure RTL expansion 
> >> >> >> >>>> doesn't
> >> >> >> >>>> scalarize (aka assign non-stack) to variables which have 
> >> >> >> >>>> accesses
> >> >> >> >>>> that would later eventually FAIL to expand when operating on 
> >> >> >> >>>> registers.
> >> >> >> >>>> That's very much related to the task at hand so we should try to
> >> >> >> >>>> at least merge the CFG walks of both (it produces a 
> >> >> >> >>>> forced_stack_vars
> >> >> >> >>>> bitmap).
> >> >> >> >>>>
> >> >> >> >>>> Can you work together with Martin to split out the access tree
> >> >> >> >>>> data structure and share it?
> >> >> >> >>>>
> >> >> >> >>>> I didn't look in detail as of how you make use of the 
> >> >> >> >>>> information
> >> >> >> >>>> yet.
> >> >> >> >>>>
> >> >> >> >>>> Thanks,
> >> >> >> >>>> Richard.
> >> >> >> >>>>
> >> >> >> >>>>> 
> >> >> >> >>>>> BR,
> >> >> >> >>>>> Jeff (Jiufu)
> >> >> >> >>>>> 
> >> >> >> >>>>> 
> >> >> >> >>>>> ---
> >> >> >> >>>>>  gcc/cfgexpand.cc                             | 567 
> >> >> >> >>>>> ++++++++++++++++++-
> >> >> >> >>>>>  gcc/expr.cc                                  |  15 +-
> >> >> >> >>>>>  gcc/function.cc                              |  26 +-
> >> >> >> >>>>>  gcc/opts.cc                                  |   8 +-
> >> >> >> >>>>>  gcc/testsuite/g++.target/powerpc/pr102024.C  |   2 +-
> >> >> >> >>>>>  gcc/testsuite/gcc.target/powerpc/pr108073.c  |  29 +
> >> >> >> >>>>>  gcc/testsuite/gcc.target/powerpc/pr65421-1.c |   6 +
> >> >> >> >>>>>  gcc/testsuite/gcc.target/powerpc/pr65421-2.c |  32 ++
> >> >> >> >>>>>  8 files changed, 675 insertions(+), 10 deletions(-)
> >> >> >> >>>>>  create mode 100644 gcc/testsuite/gcc.target/powerpc/pr108073.c
> >> >> >> >>>>>  create mode 100644 
> >> >> >> >>>>> gcc/testsuite/gcc.target/powerpc/pr65421-1.c
> >> >> >> >>>>>  create mode 100644 
> >> >> >> >>>>> gcc/testsuite/gcc.target/powerpc/pr65421-2.c
> >> >> >> >>>>> 
> >> >> >> >>>>> diff --git a/gcc/cfgexpand.cc b/gcc/cfgexpand.cc
> >> >> >> >>>>> index 85a93a547c0..95c29b6b6fe 100644
> >> >> >> >>>>> --- a/gcc/cfgexpand.cc
> >> >> >> >>>>> +++ b/gcc/cfgexpand.cc
> >> >> >> >>>>> @@ -97,6 +97,564 @@ static bool defer_stack_allocation (tree, 
> >> >> >> >>>>> bool);
> >> >> >> >>>>>  
> >> >> >> >>>>>  static void record_alignment_for_reg_var (unsigned int);
> >> >> >> >>>>>  
> >> >> >> >>>>> +/* For light SRA in expander about paramaters and returns.  */
> >> >> >> >>>>> +namespace {
> >> >> >> >>>>> +
> >> >> >> >>>>> +struct access
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  /* Each accessing on the aggragate is about OFFSET/SIZE and 
> >> >> >> >>>>> BASE.  */
> >> >> >> >>>>> +  HOST_WIDE_INT offset;
> >> >> >> >>>>> +  HOST_WIDE_INT size;
> >> >> >> >>>>> +  tree base;
> >> >> >> >>>>> +  bool writing;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  /* The context expression of this access.  */
> >> >> >> >>>>> +  tree expr;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  /* The rtx for the access: link to incoming/returning 
> >> >> >> >>>>> register(s).  */
> >> >> >> >>>>> +  rtx rtx_val;
> >> >> >> >>>>> +};
> >> >> >> >>>>> +
> >> >> >> >>>>> +typedef struct access *access_p;
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Expr (tree) -> Acess (access_p) map.  */
> >> >> >> >>>>> +static hash_map<tree, access_p> *expr_access_vec;
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Base (tree) -> Vector (vec<access_p> *) map.  */
> >> >> >> >>>>> +static hash_map<tree, auto_vec<access_p> > *base_access_vec;
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Return a vector of pointers to accesses for the variable 
> >> >> >> >>>>> given in BASE or
> >> >> >> >>>>> + NULL if there is none.  */
> >> >> >> >>>>> +
> >> >> >> >>>>> +static vec<access_p> *
> >> >> >> >>>>> +get_base_access_vector (tree base)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  return base_access_vec->get (base);
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Remove DECL from candidates for SRA.  */
> >> >> >> >>>>> +static void
> >> >> >> >>>>> +disqualify_candidate (tree decl)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  decl = get_base_address (decl);
> >> >> >> >>>>> +  base_access_vec->remove (decl);
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Create and insert access for EXPR. Return created access, 
> >> >> >> >>>>> or NULL if it is
> >> >> >> >>>>> +   not possible.  */
> >> >> >> >>>>> +static struct access *
> >> >> >> >>>>> +create_access (tree expr, bool write)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  poly_int64 poffset, psize, pmax_size;
> >> >> >> >>>>> +  bool reverse;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  tree base
> >> >> >> >>>>> +    = get_ref_base_and_extent (expr, &poffset, &psize, 
> >> >> >> >>>>> &pmax_size, &reverse);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  if (!DECL_P (base))
> >> >> >> >>>>> +    return NULL;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  vec<access_p> *access_vec = get_base_access_vector (base);
> >> >> >> >>>>> +  if (!access_vec)
> >> >> >> >>>>> +    return NULL;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  /* TODO: support reverse. */
> >> >> >> >>>>> +  if (reverse)
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      disqualify_candidate (expr);
> >> >> >> >>>>> +      return NULL;
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +
> >> >> >> >>>>> +  HOST_WIDE_INT offset, size, max_size;
> >> >> >> >>>>> +  if (!poffset.is_constant (&offset) || !psize.is_constant 
> >> >> >> >>>>> (&size)
> >> >> >> >>>>> +      || !pmax_size.is_constant (&max_size))
> >> >> >> >>>>> +    return NULL;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  if (size != max_size || size == 0 || offset < 0 || size < 0
> >> >> >> >>>>> +      || offset + size > tree_to_shwi (DECL_SIZE (base)))
> >> >> >> >>>>> +    return NULL;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  struct access *access = XNEWVEC (struct access, 1);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  memset (access, 0, sizeof (struct access));
> >> >> >> >>>>> +  access->base = base;
> >> >> >> >>>>> +  access->offset = offset;
> >> >> >> >>>>> +  access->size = size;
> >> >> >> >>>>> +  access->expr = expr;
> >> >> >> >>>>> +  access->writing = write;
> >> >> >> >>>>> +  access->rtx_val = NULL_RTX;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  access_vec->safe_push (access);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  return access;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Return true if VAR is a candidate for SRA.  */
> >> >> >> >>>>> +static bool
> >> >> >> >>>>> +add_sra_candidate (tree var)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  tree type = TREE_TYPE (var);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  if (!AGGREGATE_TYPE_P (type) || TREE_THIS_VOLATILE (var)
> >> >> >> >>>>> +      || !COMPLETE_TYPE_P (type) || !tree_fits_shwi_p 
> >> >> >> >>>>> (TYPE_SIZE (type))
> >> >> >> >>>>> +      || tree_to_shwi (TYPE_SIZE (type)) == 0
> >> >> >> >>>>> +      || TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT 
> >> >> >> >>>>> (va_list_type_node))
> >> >> >> >>>>> +    return false;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  base_access_vec->get_or_insert (var);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  return true;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Callback of walk_stmt_load_store_addr_ops visit_addr used 
> >> >> >> >>>>> to remove
> >> >> >> >>>>> +   operands with address taken.  */
> >> >> >> >>>>> +static tree
> >> >> >> >>>>> +visit_addr (tree *tp, int *, void *)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  tree op = *tp;
> >> >> >> >>>>> +  if (op && DECL_P (op))
> >> >> >> >>>>> +    disqualify_candidate (op);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  return NULL;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Scan expression EXPR and create access structures for all 
> >> >> >> >>>>> accesses to
> >> >> >> >>>>> +   candidates for scalarization.  Return the created access 
> >> >> >> >>>>> or NULL if none is
> >> >> >> >>>>> +   created.  */
> >> >> >> >>>>> +static struct access *
> >> >> >> >>>>> +build_access_from_expr (tree expr, bool write)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
> >> >> >> >>>>> +    expr = TREE_OPERAND (expr, 0);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  if (TREE_CODE (expr) == BIT_FIELD_REF || 
> >> >> >> >>>>> storage_order_barrier_p (expr)
> >> >> >> >>>>> +      || TREE_THIS_VOLATILE (expr))
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      disqualify_candidate (expr);
> >> >> >> >>>>> +      return NULL;
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +
> >> >> >> >>>>> +  switch (TREE_CODE (expr))
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      case MEM_REF: {
> >> >> >> >>>>> +      tree op = TREE_OPERAND (expr, 0);
> >> >> >> >>>>> +      if (TREE_CODE (op) == ADDR_EXPR)
> >> >> >> >>>>> +        disqualify_candidate (TREE_OPERAND (op, 0));
> >> >> >> >>>>> +      break;
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +    case ADDR_EXPR:
> >> >> >> >>>>> +    case IMAGPART_EXPR:
> >> >> >> >>>>> +    case REALPART_EXPR:
> >> >> >> >>>>> +      disqualify_candidate (TREE_OPERAND (expr, 0));
> >> >> >> >>>>> +      break;
> >> >> >> >>>>> +    case VAR_DECL:
> >> >> >> >>>>> +    case PARM_DECL:
> >> >> >> >>>>> +    case RESULT_DECL:
> >> >> >> >>>>> +    case COMPONENT_REF:
> >> >> >> >>>>> +    case ARRAY_REF:
> >> >> >> >>>>> +    case ARRAY_RANGE_REF:
> >> >> >> >>>>> +      return create_access (expr, write);
> >> >> >> >>>>> +      break;
> >> >> >> >>>>> +    default:
> >> >> >> >>>>> +      break;
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +
> >> >> >> >>>>> +  return NULL;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Scan function and look for interesting expressions and 
> >> >> >> >>>>> create access
> >> >> >> >>>>> +   structures for them.  */
> >> >> >> >>>>> +static void
> >> >> >> >>>>> +scan_function (void)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  basic_block bb;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  FOR_EACH_BB_FN (bb, cfun)
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      for (gphi_iterator gsi = gsi_start_phis (bb); 
> >> >> >> >>>>> !gsi_end_p (gsi);
> >> >> >> >>>>> +         gsi_next (&gsi))
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +        gphi *phi = gsi.phi ();
> >> >> >> >>>>> +        for (size_t i = 0; i < gimple_phi_num_args (phi); i++)
> >> >> >> >>>>> +          {
> >> >> >> >>>>> +            tree t = gimple_phi_arg_def (phi, i);
> >> >> >> >>>>> +            walk_tree (&t, visit_addr, NULL, NULL);
> >> >> >> >>>>> +          }
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +
> >> >> >> >>>>> +      for (gimple_stmt_iterator gsi = 
> >> >> >> >>>>> gsi_start_nondebug_after_labels_bb (bb);
> >> >> >> >>>>> +         !gsi_end_p (gsi); gsi_next_nondebug (&gsi))
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +        gimple *stmt = gsi_stmt (gsi);
> >> >> >> >>>>> +        switch (gimple_code (stmt))
> >> >> >> >>>>> +          {
> >> >> >> >>>>> +            case GIMPLE_RETURN: {
> >> >> >> >>>>> +              tree r = gimple_return_retval (as_a<greturn *> 
> >> >> >> >>>>> (stmt));
> >> >> >> >>>>> +              if (r && VAR_P (r) && r != DECL_RESULT 
> >> >> >> >>>>> (current_function_decl))
> >> >> >> >>>>> +                build_access_from_expr (r, true);
> >> >> >> >>>>> +            }
> >> >> >> >>>>> +            break;
> >> >> >> >>>>> +          case GIMPLE_ASSIGN:
> >> >> >> >>>>> +            if (gimple_assign_single_p (stmt) && 
> >> >> >> >>>>> !gimple_clobber_p (stmt))
> >> >> >> >>>>> +              {
> >> >> >> >>>>> +                tree lhs = gimple_assign_lhs (stmt);
> >> >> >> >>>>> +                tree rhs = gimple_assign_rhs1 (stmt);
> >> >> >> >>>>> +                if (TREE_CODE (rhs) == CONSTRUCTOR)
> >> >> >> >>>>> +                  disqualify_candidate (lhs);
> >> >> >> >>>>> +                else
> >> >> >> >>>>> +                  {
> >> >> >> >>>>> +                    build_access_from_expr (rhs, false);
> >> >> >> >>>>> +                    build_access_from_expr (lhs, true);
> >> >> >> >>>>> +                  }
> >> >> >> >>>>> +              }
> >> >> >> >>>>> +            break;
> >> >> >> >>>>> +          default:
> >> >> >> >>>>> +            walk_gimple_op (stmt, visit_addr, NULL);
> >> >> >> >>>>> +            break;
> >> >> >> >>>>> +          }
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Collect the parameter and returns with type which is 
> >> >> >> >>>>> suitable for
> >> >> >> >>>>> + * scalarization.  */
> >> >> >> >>>>> +static bool
> >> >> >> >>>>> +collect_light_sra_candidates (void)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  bool ret = false;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  /* Collect parameters.  */
> >> >> >> >>>>> +  for (tree parm = DECL_ARGUMENTS (current_function_decl); 
> >> >> >> >>>>> parm;
> >> >> >> >>>>> +       parm = DECL_CHAIN (parm))
> >> >> >> >>>>> +    ret |= add_sra_candidate (parm);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  /* Collect VARs on returns.  */
> >> >> >> >>>>> +  if (DECL_RESULT (current_function_decl))
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      edge_iterator ei;
> >> >> >> >>>>> +      edge e;
> >> >> >> >>>>> +      FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN 
> >> >> >> >>>>> (cfun)->preds)
> >> >> >> >>>>> +      if (greturn *r = safe_dyn_cast<greturn *> (*gsi_last_bb 
> >> >> >> >>>>> (e->src)))
> >> >> >> >>>>> +        {
> >> >> >> >>>>> +          tree val = gimple_return_retval (r);
> >> >> >> >>>>> +          if (val && VAR_P (val))
> >> >> >> >>>>> +            ret |= add_sra_candidate (val);
> >> >> >> >>>>> +        }
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +
> >> >> >> >>>>> +  return ret;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Now, only scalarize the parms only with reading
> >> >> >> >>>>> +   or returns only with writing.  */
> >> >> >> >>>>> +bool
> >> >> >> >>>>> +check_access_vec (tree const &base, auto_vec<access_p> const 
> >> >> >> >>>>> &access_vec,
> >> >> >> >>>>> +                auto_vec<tree> *unqualify_vec)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  bool read = false;
> >> >> >> >>>>> +  bool write = false;
> >> >> >> >>>>> +  for (unsigned int j = 0; j < access_vec.length (); j++)
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      struct access *access = access_vec[j];
> >> >> >> >>>>> +      if (access->writing)
> >> >> >> >>>>> +      write = true;
> >> >> >> >>>>> +      else
> >> >> >> >>>>> +      read = true;
> >> >> >> >>>>> +
> >> >> >> >>>>> +      if (write && read)
> >> >> >> >>>>> +      break;
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +  if ((write && read) || (!write && !read))
> >> >> >> >>>>> +    unqualify_vec->safe_push (base);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  return true;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Analyze all the accesses, remove those inprofitable 
> >> >> >> >>>>> candidates.
> >> >> >> >>>>> +   And build the expr->access map.  */
> >> >> >> >>>>> +static void
> >> >> >> >>>>> +analyze_accesses ()
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  auto_vec<tree> unqualify_vec;
> >> >> >> >>>>> +  base_access_vec->traverse<auto_vec<tree> *, 
> >> >> >> >>>>> check_access_vec> (
> >> >> >> >>>>> +    &unqualify_vec);
> >> >> >> >>>>> +
> >> >> >> >>>>> +  tree base;
> >> >> >> >>>>> +  unsigned i;
> >> >> >> >>>>> +  FOR_EACH_VEC_ELT (unqualify_vec, i, base)
> >> >> >> >>>>> +    disqualify_candidate (base);
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +static void
> >> >> >> >>>>> +prepare_expander_sra ()
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  if (optimize <= 0)
> >> >> >> >>>>> +    return;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  base_access_vec = new hash_map<tree, auto_vec<access_p> >;
> >> >> >> >>>>> +  expr_access_vec = new hash_map<tree, access_p>;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  if (collect_light_sra_candidates ())
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      scan_function ();
> >> >> >> >>>>> +      analyze_accesses ();
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +static void
> >> >> >> >>>>> +free_expander_sra ()
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  if (optimize <= 0 || !expr_access_vec)
> >> >> >> >>>>> +    return;
> >> >> >> >>>>> +  delete expr_access_vec;
> >> >> >> >>>>> +  expr_access_vec = 0;
> >> >> >> >>>>> +  delete base_access_vec;
> >> >> >> >>>>> +  base_access_vec = 0;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +} /* namespace */
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Check If there is an sra access for the expr.
> >> >> >> >>>>> +   Return the correspond scalar sym for the access. */
> >> >> >> >>>>> +rtx
> >> >> >> >>>>> +get_scalar_rtx_for_aggregate_expr (tree expr)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  if (!expr_access_vec)
> >> >> >> >>>>> +    return NULL_RTX;
> >> >> >> >>>>> +  access_p *access = expr_access_vec->get (expr);
> >> >> >> >>>>> +  return access ? (*access)->rtx_val : NULL_RTX;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +extern rtx
> >> >> >> >>>>> +expand_shift (enum tree_code, machine_mode, rtx, poly_int64, 
> >> >> >> >>>>> rtx, int);
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* Compute/Set RTX registers for those accesses on BASE.  */
> >> >> >> >>>>> +void
> >> >> >> >>>>> +set_scalar_rtx_for_aggregate_access (tree base, rtx regs)
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  if (!base_access_vec)
> >> >> >> >>>>> +    return;
> >> >> >> >>>>> +  vec<access_p> *access_vec = get_base_access_vector (base);
> >> >> >> >>>>> +  if (!access_vec)
> >> >> >> >>>>> +    return;
> >> >> >> >>>>> +
> >> >> >> >>>>> +  /* Go through each access, compute corresponding rtx(regs 
> >> >> >> >>>>> or subregs)
> >> >> >> >>>>> +     for the expression.  */
> >> >> >> >>>>> +  int n = access_vec->length ();
> >> >> >> >>>>> +  int cur_access_index = 0;
> >> >> >> >>>>> +  for (; cur_access_index < n; cur_access_index++)
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      access_p acc = (*access_vec)[cur_access_index];
> >> >> >> >>>>> +      machine_mode expr_mode = TYPE_MODE (TREE_TYPE 
> >> >> >> >>>>> (acc->expr));
> >> >> >> >>>>> +      /* non BLK in mult registers*/
> >> >> >> >>>>> +      if (expr_mode != BLKmode
> >> >> >> >>>>> +        && known_gt (acc->size, GET_MODE_BITSIZE (word_mode)))
> >> >> >> >>>>> +      break;
> >> >> >> >>>>> +
> >> >> >> >>>>> +      int start_index = -1;
> >> >> >> >>>>> +      int end_index = -1;
> >> >> >> >>>>> +      HOST_WIDE_INT left_margin_bits = 0;
> >> >> >> >>>>> +      HOST_WIDE_INT right_margin_bits = 0;
> >> >> >> >>>>> +      int cur_index = XEXP (XVECEXP (regs, 0, 0), 0) ? 0 : 1;
> >> >> >> >>>>> +      for (; cur_index < XVECLEN (regs, 0); cur_index++)
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +        rtx slot = XVECEXP (regs, 0, cur_index);
> >> >> >> >>>>> +        HOST_WIDE_INT off = UINTVAL (XEXP (slot, 1)) * 
> >> >> >> >>>>> BITS_PER_UNIT;
> >> >> >> >>>>> +        HOST_WIDE_INT size
> >> >> >> >>>>> +          = GET_MODE_BITSIZE (GET_MODE (XEXP (slot, 
> >> >> >> >>>>> 0))).to_constant ();
> >> >> >> >>>>> +        if (off <= acc->offset && off + size > acc->offset)
> >> >> >> >>>>> +          {
> >> >> >> >>>>> +            start_index = cur_index;
> >> >> >> >>>>> +            left_margin_bits = acc->offset - off;
> >> >> >> >>>>> +          }
> >> >> >> >>>>> +        if (off + size >= acc->offset + acc->size)
> >> >> >> >>>>> +          {
> >> >> >> >>>>> +            end_index = cur_index;
> >> >> >> >>>>> +            right_margin_bits = off + size - (acc->offset + 
> >> >> >> >>>>> acc->size);
> >> >> >> >>>>> +            break;
> >> >> >> >>>>> +          }
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +      /* accessing pading and outof bound.  */
> >> >> >> >>>>> +      if (start_index < 0 || end_index < 0)
> >> >> >> >>>>> +      break;
> >> >> >> >>>>> +
> >> >> >> >>>>> +      /* Need a parallel for possible multi-registers. */
> >> >> >> >>>>> +      if (expr_mode == BLKmode || end_index > start_index)
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +        /* Can not support start from middle of a register.  
> >> >> >> >>>>> */
> >> >> >> >>>>> +        if (left_margin_bits != 0)
> >> >> >> >>>>> +          break;
> >> >> >> >>>>> +
> >> >> >> >>>>> +        int len = end_index - start_index + 1;
> >> >> >> >>>>> +        const int margin = 3; /* more space for SI, HI, QI.  
> >> >> >> >>>>> */
> >> >> >> >>>>> +        rtx *tmps = XALLOCAVEC (rtx, len + (right_margin_bits 
> >> >> >> >>>>> ? margin : 0));
> >> >> >> >>>>> +
> >> >> >> >>>>> +        HOST_WIDE_INT start_off
> >> >> >> >>>>> +          = UINTVAL (XEXP (XVECEXP (regs, 0, start_index), 
> >> >> >> >>>>> 1));
> >> >> >> >>>>> +        int pos = 0;
> >> >> >> >>>>> +        for (; pos < len - (right_margin_bits ? 1 : 0); pos++)
> >> >> >> >>>>> +          {
> >> >> >> >>>>> +            int index = start_index + pos;
> >> >> >> >>>>> +            rtx orig_reg = XEXP (XVECEXP (regs, 0, index), 0);
> >> >> >> >>>>> +            machine_mode mode = GET_MODE (orig_reg);
> >> >> >> >>>>> +            rtx reg = NULL_RTX;
> >> >> >> >>>>> +            if (HARD_REGISTER_P (orig_reg))
> >> >> >> >>>>> +              {
> >> >> >> >>>>> +                /* Reading from param hard reg need to be 
> >> >> >> >>>>> moved to a temp.  */
> >> >> >> >>>>> +                gcc_assert (!acc->writing);
> >> >> >> >>>>> +                reg = gen_reg_rtx (mode);
> >> >> >> >>>>> +                emit_move_insn (reg, orig_reg);
> >> >> >> >>>>> +              }
> >> >> >> >>>>> +            else
> >> >> >> >>>>> +              reg = orig_reg;
> >> >> >> >>>>> +
> >> >> >> >>>>> +            HOST_WIDE_INT off = UINTVAL (XEXP (XVECEXP (regs, 
> >> >> >> >>>>> 0, index), 1));
> >> >> >> >>>>> +            tmps[pos]
> >> >> >> >>>>> +              = gen_rtx_EXPR_LIST (mode, reg, GEN_INT (off - 
> >> >> >> >>>>> start_off));
> >> >> >> >>>>> +          }
> >> >> >> >>>>> +
> >> >> >> >>>>> +        /* There are some fields are in part of registers.   
> >> >> >> >>>>> */
> >> >> >> >>>>> +        if (right_margin_bits != 0)
> >> >> >> >>>>> +          {
> >> >> >> >>>>> +            if (acc->writing)
> >> >> >> >>>>> +              break;
> >> >> >> >>>>> +
> >> >> >> >>>>> +            gcc_assert ((right_margin_bits % BITS_PER_UNIT) 
> >> >> >> >>>>> == 0);
> >> >> >> >>>>> +            HOST_WIDE_INT off_byte
> >> >> >> >>>>> +              = UINTVAL (XEXP (XVECEXP (regs, 0, end_index), 
> >> >> >> >>>>> 1)) - start_off;
> >> >> >> >>>>> +            rtx orig_reg = XEXP (XVECEXP (regs, 0, 
> >> >> >> >>>>> end_index), 0);
> >> >> >> >>>>> +            machine_mode orig_mode = GET_MODE (orig_reg);
> >> >> >> >>>>> +            gcc_assert (GET_MODE_CLASS (orig_mode) == 
> >> >> >> >>>>> MODE_INT);
> >> >> >> >>>>> +
> >> >> >> >>>>> +            machine_mode mode_aux[] = {SImode, HImode, 
> >> >> >> >>>>> QImode};
> >> >> >> >>>>> +            HOST_WIDE_INT reg_size
> >> >> >> >>>>> +              = GET_MODE_BITSIZE (orig_mode).to_constant ();
> >> >> >> >>>>> +            HOST_WIDE_INT off_bits = 0;
> >> >> >> >>>>> +            for (unsigned long j = 0;
> >> >> >> >>>>> +                 j < sizeof (mode_aux) / sizeof 
> >> >> >> >>>>> (mode_aux[0]); j++)
> >> >> >> >>>>> +              {
> >> >> >> >>>>> +                HOST_WIDE_INT submode_bitsize
> >> >> >> >>>>> +                  = GET_MODE_BITSIZE 
> >> >> >> >>>>> (mode_aux[j]).to_constant ();
> >> >> >> >>>>> +                if (reg_size - right_margin_bits - off_bits
> >> >> >> >>>>> +                    >= submode_bitsize)
> >> >> >> >>>>> +                  {
> >> >> >> >>>>> +                    rtx reg = gen_reg_rtx (orig_mode);
> >> >> >> >>>>> +                    emit_move_insn (reg, orig_reg);
> >> >> >> >>>>> +
> >> >> >> >>>>> +                    poly_uint64 lowpart_off
> >> >> >> >>>>> +                      = subreg_lowpart_offset (mode_aux[j], 
> >> >> >> >>>>> orig_mode);
> >> >> >> >>>>> +                    int lowpart_off_bits
> >> >> >> >>>>> +                      = lowpart_off.to_constant () * 
> >> >> >> >>>>> BITS_PER_UNIT;
> >> >> >> >>>>> +                    int shift_bits = lowpart_off_bits >= 
> >> >> >> >>>>> off_bits
> >> >> >> >>>>> +                                       ? (lowpart_off_bits - 
> >> >> >> >>>>> off_bits)
> >> >> >> >>>>> +                                       : (off_bits - 
> >> >> >> >>>>> lowpart_off_bits);
> >> >> >> >>>>> +                    if (shift_bits > 0)
> >> >> >> >>>>> +                      reg = expand_shift (RSHIFT_EXPR, 
> >> >> >> >>>>> orig_mode, reg,
> >> >> >> >>>>> +                                          shift_bits, NULL, 
> >> >> >> >>>>> 1);
> >> >> >> >>>>> +                    rtx subreg = gen_lowpart (mode_aux[j], 
> >> >> >> >>>>> reg);
> >> >> >> >>>>> +                    rtx off = GEN_INT (off_byte);
> >> >> >> >>>>> +                    tmps[pos++]
> >> >> >> >>>>> +                      = gen_rtx_EXPR_LIST (mode_aux[j], 
> >> >> >> >>>>> subreg, off);
> >> >> >> >>>>> +                    off_byte += submode_bitsize / 
> >> >> >> >>>>> BITS_PER_UNIT;
> >> >> >> >>>>> +                    off_bits += submode_bitsize;
> >> >> >> >>>>> +                  }
> >> >> >> >>>>> +              }
> >> >> >> >>>>> +          }
> >> >> >> >>>>> +
> >> >> >> >>>>> +        /* Currently, PARALLELs with register elements for 
> >> >> >> >>>>> param/returns
> >> >> >> >>>>> +           are using BLKmode.  */
> >> >> >> >>>>> +        acc->rtx_val = gen_rtx_PARALLEL (TYPE_MODE (TREE_TYPE 
> >> >> >> >>>>> (acc->expr)),
> >> >> >> >>>>> +                                         gen_rtvec_v (pos, 
> >> >> >> >>>>> tmps));
> >> >> >> >>>>> +        continue;
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +
> >> >> >> >>>>> +      /* The access corresponds to one reg.  */
> >> >> >> >>>>> +      if (end_index == start_index && left_margin_bits == 0
> >> >> >> >>>>> +        && right_margin_bits == 0)
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +        rtx orig_reg = XEXP (XVECEXP (regs, 0, start_index), 
> >> >> >> >>>>> 0);
> >> >> >> >>>>> +        rtx reg = NULL_RTX;
> >> >> >> >>>>> +        if (HARD_REGISTER_P (orig_reg))
> >> >> >> >>>>> +          {
> >> >> >> >>>>> +            /* Reading from param hard reg need to be moved 
> >> >> >> >>>>> to a temp.  */
> >> >> >> >>>>> +            gcc_assert (!acc->writing);
> >> >> >> >>>>> +            reg = gen_reg_rtx (GET_MODE (orig_reg));
> >> >> >> >>>>> +            emit_move_insn (reg, orig_reg);
> >> >> >> >>>>> +          }
> >> >> >> >>>>> +        else
> >> >> >> >>>>> +          reg = orig_reg;
> >> >> >> >>>>> +        if (GET_MODE (orig_reg) != expr_mode)
> >> >> >> >>>>> +          reg = gen_lowpart (expr_mode, reg);
> >> >> >> >>>>> +
> >> >> >> >>>>> +        acc->rtx_val = reg;
> >> >> >> >>>>> +        continue;
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +
> >> >> >> >>>>> +      /* It is accessing a filed which is part of a register. 
> >> >> >> >>>>>  */
> >> >> >> >>>>> +      scalar_int_mode imode;
> >> >> >> >>>>> +      if (!acc->writing && end_index == start_index
> >> >> >> >>>>> +        && int_mode_for_size (acc->size, 1).exists (&imode))
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +        /* get and copy original register inside the param.  
> >> >> >> >>>>> */
> >> >> >> >>>>> +        rtx orig_reg = XEXP (XVECEXP (regs, 0, start_index), 
> >> >> >> >>>>> 0);
> >> >> >> >>>>> +        machine_mode mode = GET_MODE (orig_reg);
> >> >> >> >>>>> +        gcc_assert (GET_MODE_CLASS (mode) == MODE_INT);
> >> >> >> >>>>> +        rtx reg = gen_reg_rtx (mode);
> >> >> >> >>>>> +        emit_move_insn (reg, orig_reg);
> >> >> >> >>>>> +
> >> >> >> >>>>> +        /* shift to expect part. */
> >> >> >> >>>>> +        poly_uint64 lowpart_off = subreg_lowpart_offset 
> >> >> >> >>>>> (imode, mode);
> >> >> >> >>>>> +        int lowpart_off_bits = lowpart_off.to_constant () * 
> >> >> >> >>>>> BITS_PER_UNIT;
> >> >> >> >>>>> +        int shift_bits = lowpart_off_bits >= left_margin_bits
> >> >> >> >>>>> +                           ? (lowpart_off_bits - 
> >> >> >> >>>>> left_margin_bits)
> >> >> >> >>>>> +                           : (left_margin_bits - 
> >> >> >> >>>>> lowpart_off_bits);
> >> >> >> >>>>> +        if (shift_bits > 0)
> >> >> >> >>>>> +          reg = expand_shift (RSHIFT_EXPR, mode, reg, 
> >> >> >> >>>>> shift_bits, NULL, 1);
> >> >> >> >>>>> +
> >> >> >> >>>>> +        /* move corresond part subreg to result.  */
> >> >> >> >>>>> +        rtx subreg = gen_lowpart (imode, reg);
> >> >> >> >>>>> +        rtx result = gen_reg_rtx (imode);
> >> >> >> >>>>> +        emit_move_insn (result, subreg);
> >> >> >> >>>>> +
> >> >> >> >>>>> +        if (expr_mode != imode)
> >> >> >> >>>>> +          result = gen_lowpart (expr_mode, result);
> >> >> >> >>>>> +
> >> >> >> >>>>> +        acc->rtx_val = result;
> >> >> >> >>>>> +        continue;
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +
> >> >> >> >>>>> +      break;
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +
> >> >> >> >>>>> +  /* Some access expr(s) are not scalarized.  */
> >> >> >> >>>>> +  if (cur_access_index != n)
> >> >> >> >>>>> +    disqualify_candidate (base);
> >> >> >> >>>>> +  else
> >> >> >> >>>>> +    {
> >> >> >> >>>>> +      /* Add elements to expr->access map.  */
> >> >> >> >>>>> +      for (int j = 0; j < n; j++)
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +        access_p access = (*access_vec)[j];
> >> >> >> >>>>> +        expr_access_vec->put (access->expr, access);
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +    }
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> +void
> >> >> >> >>>>> +set_scalar_rtx_for_returns ()
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  tree res = DECL_RESULT (current_function_decl);
> >> >> >> >>>>> +  gcc_assert (res);
> >> >> >> >>>>> +  edge_iterator ei;
> >> >> >> >>>>> +  edge e;
> >> >> >> >>>>> +  FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
> >> >> >> >>>>> +    if (greturn *r = safe_dyn_cast<greturn *> (*gsi_last_bb 
> >> >> >> >>>>> (e->src)))
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +      tree val = gimple_return_retval (r);
> >> >> >> >>>>> +      if (val && VAR_P (val))
> >> >> >> >>>>> +        set_scalar_rtx_for_aggregate_access (val, DECL_RTL 
> >> >> >> >>>>> (res));
> >> >> >> >>>>> +      }
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>>  /* Return an expression tree corresponding to the RHS of 
> >> >> >> >>>>> GIMPLE
> >> >> >> >>>>>     statement STMT.  */
> >> >> >> >>>>>  
> >> >> >> >>>>> @@ -3778,7 +4336,8 @@ expand_return (tree retval)
> >> >> >> >>>>>  
> >> >> >> >>>>>    /* If we are returning the RESULT_DECL, then the value has 
> >> >> >> >>>>> already
> >> >> >> >>>>>       been stored into it, so we don't have to do anything 
> >> >> >> >>>>> special.  */
> >> >> >> >>>>> -  if (TREE_CODE (retval_rhs) == RESULT_DECL)
> >> >> >> >>>>> +  if (TREE_CODE (retval_rhs) == RESULT_DECL
> >> >> >> >>>>> +      || get_scalar_rtx_for_aggregate_expr (retval_rhs))
> >> >> >> >>>>>      expand_value_return (result_rtl);
> >> >> >> >>>>>  
> >> >> >> >>>>>    /* If the result is an aggregate that is being returned in 
> >> >> >> >>>>> one (or more)
> >> >> >> >>>>> @@ -4422,6 +4981,9 @@ expand_debug_expr (tree exp)
> >> >> >> >>>>>    int unsignedp = TYPE_UNSIGNED (TREE_TYPE (exp));
> >> >> >> >>>>>    addr_space_t as;
> >> >> >> >>>>>    scalar_int_mode op0_mode, op1_mode, addr_mode;
> >> >> >> >>>>> +  rtx x = get_scalar_rtx_for_aggregate_expr (exp);
> >> >> >> >>>>> +  if (x)
> >> >> >> >>>>> +    return NULL_RTX;/* optimized out.  */
> >> >> >> >>>>>  
> >> >> >> >>>>>    switch (TREE_CODE_CLASS (TREE_CODE (exp)))
> >> >> >> >>>>>      {
> >> >> >> >>>>> @@ -6630,6 +7192,8 @@ pass_expand::execute (function *fun)
> >> >> >> >>>>>            avoid_deep_ter_for_debug (gsi_stmt (gsi), 0);
> >> >> >> >>>>>      }
> >> >> >> >>>>>  
> >> >> >> >>>>> +  prepare_expander_sra ();
> >> >> >> >>>>> +
> >> >> >> >>>>>    /* Mark arrays indexed with non-constant indices with 
> >> >> >> >>>>> TREE_ADDRESSABLE.  */
> >> >> >> >>>>>    auto_bitmap forced_stack_vars;
> >> >> >> >>>>>    discover_nonconstant_array_refs (forced_stack_vars);
> >> >> >> >>>>> @@ -7062,6 +7626,7 @@ pass_expand::execute (function *fun)
> >> >> >> >>>>>        loop_optimizer_finalize ();
> >> >> >> >>>>>      }
> >> >> >> >>>>>  
> >> >> >> >>>>> +  free_expander_sra ();
> >> >> >> >>>>>    timevar_pop (TV_POST_EXPAND);
> >> >> >> >>>>>  
> >> >> >> >>>>>    return 0;
> >> >> >> >>>>> diff --git a/gcc/expr.cc b/gcc/expr.cc
> >> >> >> >>>>> index 56b51876f80..b970f98e689 100644
> >> >> >> >>>>> --- a/gcc/expr.cc
> >> >> >> >>>>> +++ b/gcc/expr.cc
> >> >> >> >>>>> @@ -100,6 +100,7 @@ static void do_tablejump (rtx, 
> >> >> >> >>>>> machine_mode, rtx, rtx, rtx,
> >> >> >> >>>>>  static rtx const_vector_from_tree (tree);
> >> >> >> >>>>>  static tree tree_expr_size (const_tree);
> >> >> >> >>>>>  static void convert_mode_scalar (rtx, rtx, int);
> >> >> >> >>>>> +rtx get_scalar_rtx_for_aggregate_expr (tree);
> >> >> >> >>>>>  
> >> >> >> >>>>>  
> >> >> >> >>>>>  /* This is run to set up which modes can be used
> >> >> >> >>>>> @@ -5623,11 +5624,12 @@ expand_assignment (tree to, tree from, 
> >> >> >> >>>>> bool nontemporal)
> >> >> >> >>>>>       Assignment of an array element at a constant index, and 
> >> >> >> >>>>> assignment of
> >> >> >> >>>>>       an array element in an unaligned packed structure field, 
> >> >> >> >>>>> has the same
> >> >> >> >>>>>       problem.  Same for (partially) storing into a non-memory 
> >> >> >> >>>>> object.  */
> >> >> >> >>>>> -  if (handled_component_p (to)
> >> >> >> >>>>> -      || (TREE_CODE (to) == MEM_REF
> >> >> >> >>>>> -        && (REF_REVERSE_STORAGE_ORDER (to)
> >> >> >> >>>>> -            || mem_ref_refers_to_non_mem_p (to)))
> >> >> >> >>>>> -      || TREE_CODE (TREE_TYPE (to)) == ARRAY_TYPE)
> >> >> >> >>>>> +  if (!get_scalar_rtx_for_aggregate_expr (to)
> >> >> >> >>>>> +      && (handled_component_p (to)
> >> >> >> >>>>> +        || (TREE_CODE (to) == MEM_REF
> >> >> >> >>>>> +            && (REF_REVERSE_STORAGE_ORDER (to)
> >> >> >> >>>>> +                || mem_ref_refers_to_non_mem_p (to)))
> >> >> >> >>>>> +        || TREE_CODE (TREE_TYPE (to)) == ARRAY_TYPE))
> >> >> >> >>>>>      {
> >> >> >> >>>>>        machine_mode mode1;
> >> >> >> >>>>>        poly_int64 bitsize, bitpos;
> >> >> >> >>>>> @@ -8995,6 +8997,9 @@ expand_expr_real (tree exp, rtx target, 
> >> >> >> >>>>> machine_mode tmode,
> >> >> >> >>>>>        ret = CONST0_RTX (tmode);
> >> >> >> >>>>>        return ret ? ret : const0_rtx;
> >> >> >> >>>>>      }
> >> >> >> >>>>> +  rtx x = get_scalar_rtx_for_aggregate_expr (exp);
> >> >> >> >>>>> +  if (x)
> >> >> >> >>>>> +    return x;
> >> >> >> >>>>>  
> >> >> >> >>>>>    ret = expand_expr_real_1 (exp, target, tmode, modifier, 
> >> >> >> >>>>> alt_rtl,
> >> >> >> >>>>>                            inner_reference_p);
> >> >> >> >>>>> diff --git a/gcc/function.cc b/gcc/function.cc
> >> >> >> >>>>> index 82102ed78d7..262d3f17e72 100644
> >> >> >> >>>>> --- a/gcc/function.cc
> >> >> >> >>>>> +++ b/gcc/function.cc
> >> >> >> >>>>> @@ -2742,6 +2742,9 @@ assign_parm_find_stack_rtl (tree parm, 
> >> >> >> >>>>> struct assign_parm_data_one *data)
> >> >> >> >>>>>    data->stack_parm = stack_parm;
> >> >> >> >>>>>  }
> >> >> >> >>>>>  
> >> >> >> >>>>> +extern void
> >> >> >> >>>>> +set_scalar_rtx_for_aggregate_access (tree, rtx);
> >> >> >> >>>>> +
> >> >> >> >>>>>  /* A subroutine of assign_parms.  Adjust DATA->ENTRY_RTL such 
> >> >> >> >>>>> that it's
> >> >> >> >>>>>     always valid and contiguous.  */
> >> >> >> >>>>>  
> >> >> >> >>>>> @@ -3117,8 +3120,21 @@ assign_parm_setup_block (struct 
> >> >> >> >>>>> assign_parm_data_all *all,
> >> >> >> >>>>>          emit_move_insn (mem, entry_parm);
> >> >> >> >>>>>        }
> >> >> >> >>>>>        else
> >> >> >> >>>>> -      move_block_from_reg (REGNO (entry_parm), mem,
> >> >> >> >>>>> -                           size_stored / UNITS_PER_WORD);
> >> >> >> >>>>> +      {
> >> >> >> >>>>> +        int regno = REGNO (entry_parm);
> >> >> >> >>>>> +        int nregs = size_stored / UNITS_PER_WORD;
> >> >> >> >>>>> +        move_block_from_reg (regno, mem, nregs);
> >> >> >> >>>>> +
> >> >> >> >>>>> +        rtx *tmps = XALLOCAVEC (rtx, nregs);
> >> >> >> >>>>> +        machine_mode mode = word_mode;
> >> >> >> >>>>> +        for (int i = 0; i < nregs; i++)
> >> >> >> >>>>> +          tmps[i] = gen_rtx_EXPR_LIST (
> >> >> >> >>>>> +            VOIDmode, gen_rtx_REG (mode, regno + i),
> >> >> >> >>>>> +            GEN_INT (GET_MODE_SIZE (mode).to_constant () * 
> >> >> >> >>>>> i));
> >> >> >> >>>>> +
> >> >> >> >>>>> +        rtx regs = gen_rtx_PARALLEL (BLKmode, gen_rtvec_v 
> >> >> >> >>>>> (nregs, tmps));
> >> >> >> >>>>> +        set_scalar_rtx_for_aggregate_access (parm, regs);
> >> >> >> >>>>> +      }
> >> >> >> >>>>>      }
> >> >> >> >>>>>    else if (data->stack_parm == 0 && !TYPE_EMPTY_P 
> >> >> >> >>>>> (data->arg.type))
> >> >> >> >>>>>      {
> >> >> >> >>>>> @@ -3718,6 +3734,10 @@ assign_parms (tree fndecl)
> >> >> >> >>>>>        else
> >> >> >> >>>>>        set_decl_incoming_rtl (parm, data.entry_parm, false);
> >> >> >> >>>>>  
> >> >> >> >>>>> +      rtx incoming = DECL_INCOMING_RTL (parm);
> >> >> >> >>>>> +      if (GET_CODE (incoming) == PARALLEL)
> >> >> >> >>>>> +      set_scalar_rtx_for_aggregate_access (parm, incoming);
> >> >> >> >>>>> +
> >> >> >> >>>>>        assign_parm_adjust_stack_rtl (&data);
> >> >> >> >>>>>  
> >> >> >> >>>>>        if (assign_parm_setup_block_p (&data))
> >> >> >> >>>>> @@ -5037,6 +5057,7 @@ stack_protect_epilogue (void)
> >> >> >> >>>>>     the function's parameters, which must be run at any return 
> >> >> >> >>>>> statement.  */
> >> >> >> >>>>>  
> >> >> >> >>>>>  bool currently_expanding_function_start;
> >> >> >> >>>>> +extern void set_scalar_rtx_for_returns ();
> >> >> >> >>>>>  void
> >> >> >> >>>>>  expand_function_start (tree subr)
> >> >> >> >>>>>  {
> >> >> >> >>>>> @@ -5138,6 +5159,7 @@ expand_function_start (tree subr)
> >> >> >> >>>>>            {
> >> >> >> >>>>>              gcc_assert (GET_CODE (hard_reg) == PARALLEL);
> >> >> >> >>>>>              set_parm_rtl (res, gen_group_rtx (hard_reg));
> >> >> >> >>>>> +            set_scalar_rtx_for_returns ();
> >> >> >> >>>>>            }
> >> >> >> >>>>>        }
> >> >> >> >>>>>  
> >> >> >> >>>>> diff --git a/gcc/opts.cc b/gcc/opts.cc
> >> >> >> >>>>> index 86b94d62b58..5e129a1cc49 100644
> >> >> >> >>>>> --- a/gcc/opts.cc
> >> >> >> >>>>> +++ b/gcc/opts.cc
> >> >> >> >>>>> @@ -1559,6 +1559,10 @@ public:
> >> >> >> >>>>>    vec<const char *> m_values;
> >> >> >> >>>>>  };
> >> >> >> >>>>>  
> >> >> >> >>>>> +#ifdef __GNUC__
> >> >> >> >>>>> +#pragma GCC diagnostic push
> >> >> >> >>>>> +#pragma GCC diagnostic ignored "-Wformat-truncation"
> >> >> >> >>>>> +#endif
> >> >> >> >>>>>  /* Print help for a specific front-end, etc.  */
> >> >> >> >>>>>  static void
> >> >> >> >>>>>  print_filtered_help (unsigned int include_flags,
> >> >> >> >>>>> @@ -1913,7 +1917,9 @@ print_filtered_help (unsigned int 
> >> >> >> >>>>> include_flags,
> >> >> >> >>>>>        printf ("\n\n");
> >> >> >> >>>>>      }
> >> >> >> >>>>>  }
> >> >> >> >>>>> -
> >> >> >> >>>>> +#ifdef __GNUC__
> >> >> >> >>>>> +#pragma GCC diagnostic pop
> >> >> >> >>>>> +#endif
> >> >> >> >>>>>  /* Display help for a specified type of option.
> >> >> >> >>>>>     The options must have ALL of the INCLUDE_FLAGS set
> >> >> >> >>>>>     ANY of the flags in the ANY_FLAGS set
> >> >> >> >>>>> diff --git a/gcc/testsuite/g++.target/powerpc/pr102024.C 
> >> >> >> >>>>> b/gcc/testsuite/g++.target/powerpc/pr102024.C
> >> >> >> >>>>> index 769585052b5..c8995cae707 100644
> >> >> >> >>>>> --- a/gcc/testsuite/g++.target/powerpc/pr102024.C
> >> >> >> >>>>> +++ b/gcc/testsuite/g++.target/powerpc/pr102024.C
> >> >> >> >>>>> @@ -5,7 +5,7 @@
> >> >> >> >>>>>  // Test that a zero-width bit field in an otherwise 
> >> >> >> >>>>> homogeneous aggregate
> >> >> >> >>>>>  // generates a psabi warning and passes arguments in GPRs.
> >> >> >> >>>>>  
> >> >> >> >>>>> -// { dg-final { scan-assembler-times {\mstd\M} 4 } }
> >> >> >> >>>>> +// { dg-final { scan-assembler-times {\mmtvsrd\M} 4 } }
> >> >> >> >>>>>  
> >> >> >> >>>>>  struct a_thing
> >> >> >> >>>>>  {
> >> >> >> >>>>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr108073.c 
> >> >> >> >>>>> b/gcc/testsuite/gcc.target/powerpc/pr108073.c
> >> >> >> >>>>> new file mode 100644
> >> >> >> >>>>> index 00000000000..7dd1a4a326a
> >> >> >> >>>>> --- /dev/null
> >> >> >> >>>>> +++ b/gcc/testsuite/gcc.target/powerpc/pr108073.c
> >> >> >> >>>>> @@ -0,0 +1,29 @@
> >> >> >> >>>>> +/* { dg-do run } */
> >> >> >> >>>>> +/* { dg-options "-O2 -save-temps" } */
> >> >> >> >>>>> +
> >> >> >> >>>>> +typedef struct DF {double a[4]; short s1; short s2; short s3; 
> >> >> >> >>>>> short s4; } DF;
> >> >> >> >>>>> +typedef struct SF {float a[4]; int i1; int i2; } SF;
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* { dg-final { scan-assembler-times {\mmtvsrd\M} 3 {target { 
> >> >> >> >>>>> has_arch_ppc64 && has_arch_pwr8 } } } } */
> >> >> >> >>>>> +/* { dg-final { scan-assembler-not {\mlwz\M} {target { 
> >> >> >> >>>>> has_arch_ppc64 && has_arch_pwr8 } } } } */
> >> >> >> >>>>> +/* { dg-final { scan-assembler-not {\mlhz\M} {target { 
> >> >> >> >>>>> has_arch_ppc64 && has_arch_pwr8 } } } } */
> >> >> >> >>>>> +short  __attribute__ ((noipa)) foo_hi (DF a, int flag){if 
> >> >> >> >>>>> (flag == 2)return a.s2+a.s3;return 0;}
> >> >> >> >>>>> +int  __attribute__ ((noipa)) foo_si (SF a, int flag){if (flag 
> >> >> >> >>>>> == 2)return a.i2+a.i1;return 0;}
> >> >> >> >>>>> +double __attribute__ ((noipa)) foo_df (DF arg, int flag){if 
> >> >> >> >>>>> (flag == 2)return arg.a[3];else return 0.0;}
> >> >> >> >>>>> +float  __attribute__ ((noipa)) foo_sf (SF arg, int flag){if 
> >> >> >> >>>>> (flag == 2)return arg.a[2]; return 0;}
> >> >> >> >>>>> +float  __attribute__ ((noipa)) foo_sf1 (SF arg, int flag){if 
> >> >> >> >>>>> (flag == 2)return arg.a[1];return 0;}
> >> >> >> >>>>> +
> >> >> >> >>>>> +DF gdf = {{1.0,2.0,3.0,4.0}, 1, 2, 3, 4};
> >> >> >> >>>>> +SF gsf = {{1.0f,2.0f,3.0f,4.0f}, 1, 2};
> >> >> >> >>>>> +
> >> >> >> >>>>> +int main()
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  if (!(foo_hi (gdf, 2) == 5 && foo_si (gsf, 2) == 3 && 
> >> >> >> >>>>> foo_df (gdf, 2) == 4.0
> >> >> >> >>>>> +      && foo_sf (gsf, 2) == 3.0 && foo_sf1 (gsf, 2) == 2.0))
> >> >> >> >>>>> +    __builtin_abort ();
> >> >> >> >>>>> +  if (!(foo_hi (gdf, 1) == 0 && foo_si (gsf, 1) == 0 && 
> >> >> >> >>>>> foo_df (gdf, 1) == 0
> >> >> >> >>>>> +      && foo_sf (gsf, 1) == 0 && foo_sf1 (gsf, 1) == 0))
> >> >> >> >>>>> +    __builtin_abort ();
> >> >> >> >>>>> +  return 0;
> >> >> >> >>>>> +}
> >> >> >> >>>>> +
> >> >> >> >>>>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr65421-1.c 
> >> >> >> >>>>> b/gcc/testsuite/gcc.target/powerpc/pr65421-1.c
> >> >> >> >>>>> new file mode 100644
> >> >> >> >>>>> index 00000000000..4e1f87f7939
> >> >> >> >>>>> --- /dev/null
> >> >> >> >>>>> +++ b/gcc/testsuite/gcc.target/powerpc/pr65421-1.c
> >> >> >> >>>>> @@ -0,0 +1,6 @@
> >> >> >> >>>>> +/* PR target/65421 */
> >> >> >> >>>>> +/* { dg-options "-O2" } */
> >> >> >> >>>>> +
> >> >> >> >>>>> +typedef struct LARGE {double a[4]; int arr[32];} LARGE;
> >> >> >> >>>>> +LARGE foo (LARGE a){return a;}
> >> >> >> >>>>> +/* { dg-final { scan-assembler-times {\mmemcpy\M} 1 } } */
> >> >> >> >>>>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr65421-2.c 
> >> >> >> >>>>> b/gcc/testsuite/gcc.target/powerpc/pr65421-2.c
> >> >> >> >>>>> new file mode 100644
> >> >> >> >>>>> index 00000000000..8a8e1a0e996
> >> >> >> >>>>> --- /dev/null
> >> >> >> >>>>> +++ b/gcc/testsuite/gcc.target/powerpc/pr65421-2.c
> >> >> >> >>>>> @@ -0,0 +1,32 @@
> >> >> >> >>>>> +/* PR target/65421 */
> >> >> >> >>>>> +/* { dg-options "-O2" } */
> >> >> >> >>>>> +/* { dg-require-effective-target powerpc_elfv2 } */
> >> >> >> >>>>> +/* { dg-require-effective-target has_arch_ppc64 } */
> >> >> >> >>>>> +
> >> >> >> >>>>> +typedef struct FLOATS
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  double a[3];
> >> >> >> >>>>> +} FLOATS;
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* 3 lfd after returns also optimized */
> >> >> >> >>>>> +/* FLOATS ret_arg_pt (FLOATS *a){return *a;} */
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* 3 stfd */
> >> >> >> >>>>> +void st_arg (FLOATS a, FLOATS *p) {*p = a;}
> >> >> >> >>>>> +/* { dg-final { scan-assembler-times {\mstfd\M} 3 } } */
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* blr */
> >> >> >> >>>>> +FLOATS ret_arg (FLOATS a) {return a;}
> >> >> >> >>>>> +
> >> >> >> >>>>> +typedef struct MIX
> >> >> >> >>>>> +{
> >> >> >> >>>>> +  double a[2];
> >> >> >> >>>>> +  long l;
> >> >> >> >>>>> +} MIX;
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* std 3 param regs to return slot */
> >> >> >> >>>>> +MIX ret_arg1 (MIX a) {return a;}
> >> >> >> >>>>> +/* { dg-final { scan-assembler-times {\mstd\M} 3 } } */
> >> >> >> >>>>> +
> >> >> >> >>>>> +/* count insns */
> >> >> >> >>>>> +/* { dg-final { scan-assembler-times {(?n)^\s+[a-z]} 9 } } */
> >> >> >> >>>>> 
> >> >> >> >>>>
> >> >> >> >>>> -- 
> >> >> >> >>>> Richard Biener <rguent...@suse.de>
> >> >> >> >>>> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 
> >> >> >> >>>> Nuernberg,
> >> >> >> >>>> Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien 
> >> >> >> >>>> Moerman;
> >> >> >> >>>> HRB 36809 (AG Nuernberg)
> >> >> >> 
> >> >> 
> >> 
> 

-- 
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)

Reply via email to