GCC Middle and Back End API Reference
tree-vect-patterns.c File Reference
#include "diagnostic-core.h"
Include dependency graph for tree-vect-patterns.c:

Functions

static gimple vect_recog_widen_sum_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_widen_mult_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_dot_prod_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_pow_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_over_widening_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_widen_shift_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_rotate_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_vector_vector_shift_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_divmod_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_mixed_size_cond_pattern (vec< gimple > *, tree *, tree *)
static gimple vect_recog_bool_pattern (vec< gimple > *, tree *, tree *)
static void append_pattern_def_seq ()
static void new_pattern_def_seq ()
static bool vect_same_loop_or_bb_p ()
static gimple vect_single_imm_use ()
static bool type_conversion_p (tree name, gimple use_stmt, bool check_sign, tree *orig_type, gimple *def_stmt, bool *promotion)
static tree vect_recog_temp_ssa_var ()
static bool vect_handle_widen_op_by_const (gimple stmt, enum tree_code code, tree const_oprnd, tree *oprnd, vec< gimple > *stmts, tree type, tree *half_type, gimple def_stmt)
static bool vect_operation_fits_smaller_type (gimple stmt, tree def, tree *new_type, tree *op0, tree *op1, gimple *new_def_stmt, vec< gimple > *stmts)
static gimple vect_recog_rotate_pattern ()
static bool check_bool_pattern ()
static tree adjust_bool_pattern_cast ()
static tree adjust_bool_pattern (tree var, tree out_type, tree trueval, vec< gimple > *stmts)
static void vect_mark_pattern_stmts (gimple orig_stmt, gimple pattern_stmt, tree pattern_vectype)
static void vect_pattern_recog_1 (vect_recog_func_ptr vect_recog_func, gimple_stmt_iterator si, vec< gimple > *stmts_to_replace)
void vect_pattern_recog ()

Variables

static vect_recog_func_ptr vect_vect_recog_func_ptrs [NUM_PATTERNS]

Function Documentation

static tree adjust_bool_pattern ( tree  var,
tree  out_type,
tree  trueval,
vec< gimple > *  stmts 
)
static
Helper function of vect_recog_bool_pattern.  Do the actual transformations,
   recursively.  VAR is an SSA_NAME that should be transformed from bool
   to a wider integer type, OUT_TYPE is the desired final integer type of
   the whole pattern, TRUEVAL should be NULL unless optimizing
   BIT_AND_EXPR into a COND_EXPR with one integer from one of the operands
   in the then_clause, STMTS is where statements with added pattern stmts
   should be pushed to.   

References absu_hwi(), adjust_bool_pattern_cast(), build_int_cst(), build_nonstandard_integer_type(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), gimple_location(), gimple_set_location(), tcc_comparison, useless_type_conversion_p(), vect_recog_temp_ssa_var(), and vinfo_for_stmt().

Referenced by vect_recog_bool_pattern().

static tree adjust_bool_pattern_cast ( )
static
Helper function of adjust_bool_pattern.  Add a cast to TYPE to a previous
   stmt (SSA_NAME_DEF_STMT of VAR) by moving the COND_EXPR from RELATED_STMT
   to PATTERN_DEF_SEQ and adding a cast as RELATED_STMT.   

References gimple_assign_lhs(), gimple_build_assign_with_ops(), new_pattern_def_seq(), vect_recog_temp_ssa_var(), and vinfo_for_stmt().

Referenced by adjust_bool_pattern().

static void append_pattern_def_seq ( )
inlinestatic
static bool check_bool_pattern ( )
static
static bool type_conversion_p ( tree  name,
gimple  use_stmt,
bool  check_sign,
tree orig_type,
gimple def_stmt,
bool *  promotion 
)
static
Check whether NAME, an ssa-name used in USE_STMT,
   is a result of a type promotion or demotion, such that:
     DEF_STMT: NAME = NOP (name0)
   where the type of name0 (ORIG_TYPE) is smaller/bigger than the type of NAME.
   If CHECK_SIGN is TRUE, check that either both types are signed or both are
   unsigned.   

References gimple_assign_rhs1(), gimple_assign_rhs_code(), is_gimple_assign(), vect_constant_def, vect_external_def, vect_internal_def, vect_is_simple_use(), and vinfo_for_stmt().

Referenced by vect_operation_fits_smaller_type(), vect_recog_dot_prod_pattern(), vect_recog_mixed_size_cond_pattern(), vect_recog_widen_mult_pattern(), vect_recog_widen_shift_pattern(), and vect_recog_widen_sum_pattern().

static bool vect_handle_widen_op_by_const ( gimple  stmt,
enum tree_code  code,
tree  const_oprnd,
tree oprnd,
vec< gimple > *  stmts,
tree  type,
tree half_type,
gimple  def_stmt 
)
static
Handle widening operation by a constant.  At the moment we support MULT_EXPR
   and LSHIFT_EXPR.

   For MULT_EXPR we check that CONST_OPRND fits HALF_TYPE, and for LSHIFT_EXPR
   we check that CONST_OPRND is less or equal to the size of HALF_TYPE.

   Otherwise, if the type of the result (TYPE) is at least 4 times bigger than
   HALF_TYPE, and there is an intermediate type (2 times smaller than TYPE)
   that satisfies the above restrictions,  we can perform a widening opeartion
   from the intermediate type to TYPE and replace a_T = (TYPE) a_t;
   with a_it = (interm_type) a_t;   

References build_nonstandard_integer_type(), compare_tree_int(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), int_fits_type_p(), is_gimple_assign(), make_ssa_name(), vect_same_loop_or_bb_p(), and vinfo_for_stmt().

Referenced by vect_recog_widen_mult_pattern(), and vect_recog_widen_shift_pattern().

static void vect_mark_pattern_stmts ( gimple  orig_stmt,
gimple  pattern_stmt,
tree  pattern_vectype 
)
inlinestatic
Mark statements that are involved in a pattern.   

References gimple_set_bb(), gsi_end_p(), gsi_next(), gsi_stmt(), new_stmt_vec_info(), set_vinfo_for_stmt(), si, and vinfo_for_stmt().

Referenced by vect_pattern_recog_1().

static bool vect_operation_fits_smaller_type ( gimple  stmt,
tree  def,
tree new_type,
tree op0,
tree op1,
gimple new_def_stmt,
vec< gimple > *  stmts 
)
static
Return TRUE if the operation in STMT can be performed on a smaller type.

   Input:
   STMT - a statement to check.
   DEF - we support operations with two operands, one of which is constant.
         The other operand can be defined by a demotion operation, or by a
         previous statement in a sequence of over-promoted operations.  In the
         later case DEF is used to replace that operand.  (It is defined by a
         pattern statement we created for the previous statement in the
         sequence).

   Input/output:
   NEW_TYPE - Output: a smaller type that we are trying to use.  Input: if not
         NULL, it's the type of DEF.
   STMTS - additional pattern statements.  If a pattern statement (type
         conversion) is created in this function, its original statement is
         added to STMTS.

   Output:
   OP0, OP1 - if the operation fits a smaller type, OP0 and OP1 are the new
         operands to use in the new pattern statement for STMT (will be created
         in vect_recog_over_widening_pattern ()).
   NEW_DEF_STMT - in case DEF has to be promoted, we create two pattern
         statements for STMT: the first one is a type promotion and the second
         one is the operation itself.  We return the type promotion statement
         in NEW_DEF_STMT and further store it in STMT_VINFO_PATTERN_DEF_SEQ of
         the second pattern statement.   

References build_nonstandard_integer_type(), compare_tree_int(), first, gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), gimple_expr_type(), has_single_use(), int_fits_type_p(), is_gimple_assign(), make_ssa_name(), type(), type_conversion_p(), vect_same_loop_or_bb_p(), vect_supportable_shift(), and vinfo_for_stmt().

Referenced by vect_recog_over_widening_pattern().

void vect_pattern_recog ( )
Function vect_pattern_recog

   Input:
   LOOP_VINFO - a struct_loop_info of a loop in which we want to look for
        computation idioms.

   Output - for each computation idiom that is detected we create a new stmt
        that provides the same functionality and that can be vectorized.  We
        also record some information in the struct_stmt_info of the relevant
        stmts, as explained below:

   At the entry to this function we have the following stmts, with the
   following initial value in the STMT_VINFO fields:

         stmt                     in_pattern_p  related_stmt    vec_stmt
         S1: a_i = ....                 -       -               -
         S2: a_2 = ..use(a_i)..         -       -               -
         S3: a_1 = ..use(a_2)..         -       -               -
         S4: a_0 = ..use(a_1)..         -       -               -
         S5: ... = ..use(a_0)..         -       -               -

   Say the sequence {S1,S2,S3,S4} was detected as a pattern that can be
   represented by a single stmt.  We then:
   - create a new stmt S6 equivalent to the pattern (the stmt is not
     inserted into the code)
   - fill in the STMT_VINFO fields as follows:

                                  in_pattern_p  related_stmt    vec_stmt
         S1: a_i = ....                 -       -               -
         S2: a_2 = ..use(a_i)..         -       -               -
         S3: a_1 = ..use(a_2)..         -       -               -
         S4: a_0 = ..use(a_1)..         true    S6              -
          '---> S6: a_new = ....        -       S4              -
         S5: ... = ..use(a_0)..         -       -               -

   (the last stmt in the pattern (S4) and the new pattern stmt (S6) point
   to each other through the RELATED_STMT field).

   S6 will be marked as relevant in vect_mark_stmts_to_be_vectorized instead
   of S4 because it will replace all its uses.  Stmts {S1,S2,S3} will
   remain irrelevant unless used by stmts other than S4.

   If vectorization succeeds, vect_transform_stmt will skip over {S1,S2,S3}
   (because they are marked as irrelevant).  It will vectorize S6, and record
   a pointer to the new vector stmt VS6 from S6 (as usual).
   S4 will be skipped, and S5 will be vectorized as usual:

                                  in_pattern_p  related_stmt    vec_stmt
         S1: a_i = ....                 -       -               -
         S2: a_2 = ..use(a_i)..         -       -               -
         S3: a_1 = ..use(a_2)..         -       -               -
       > VS6: va_new = ....             -       -               -
         S4: a_0 = ..use(a_1)..         true    S6              VS6
          '---> S6: a_new = ....        -       S4              VS6
       > VS5: ... = ..vuse(va_new)..    -       -               -
         S5: ... = ..use(a_0)..         -       -               -

   DCE could then get rid of {S1,S2,S3,S4,S5} (if their defs are not used
   elsewhere), and we'll end up with:

        VS6: va_new = ....
        VS5: ... = ..vuse(va_new)..

   In case of more than one pattern statements, e.g., widen-mult with
   intermediate type:

     S1  a_t = ;
     S2  a_T = (TYPE) a_t;
           '--> S3: a_it = (interm_type) a_t;
     S4  prod_T = a_T * CONST;
           '--> S5: prod_T' = a_it w* CONST;

   there may be other users of a_T outside the pattern.  In that case S2 will
   be marked as relevant (as well as S3), and both S2 and S3 will be analyzed
   and vectorized.  The vector stmt VS2 will be recorded in S2, and VS3 will
   be recorded in S3.   

References dump_enabled_p(), dump_printf_loc(), gsi_end_p(), gsi_next(), gsi_start_bb(), gsi_stmt(), loop::num_nodes, si, vect_location, vect_pattern_recog_1(), vect_vect_recog_func_ptrs, and vinfo_for_stmt().

Referenced by vect_analyze_loop_2(), and vect_slp_analyze_bb_1().

static void vect_pattern_recog_1 ( vect_recog_func_ptr  vect_recog_func,
gimple_stmt_iterator  si,
vec< gimple > *  stmts_to_replace 
)
static
Function vect_pattern_recog_1

   Input:
   PATTERN_RECOG_FUNC: A pointer to a function that detects a certain
        computation pattern.
   STMT: A stmt from which the pattern search should start.

   If PATTERN_RECOG_FUNC successfully detected the pattern, it creates an
   expression that computes the same functionality and can be used to
   replace the sequence of stmts that are involved in the pattern.

   Output:
   This function checks if the expression returned by PATTERN_RECOG_FUNC is
   supported in vector form by the target.  We use 'TYPE_IN' to obtain the
   relevant vector type. If 'TYPE_IN' is already a vector type, then this
   indicates that target support had already been checked by PATTERN_RECOG_FUNC.
   If 'TYPE_OUT' is also returned by PATTERN_RECOG_FUNC, we check that it fits
   to the available target pattern.

   This function also does some bookkeeping, as explained in the documentation
   for vect_recog_pattern.   

References dump_enabled_p(), dump_gimple_stmt(), dump_printf_loc(), get_vectype_for_scalar_type(), gimple_assign_rhs_code(), gsi_stmt(), insn_data, is_gimple_assign(), is_gimple_call(), loop::next, optab_default, optab_for_tree_code(), optab_handler(), vect_location, vect_mark_pattern_stmts(), and vinfo_for_stmt().

Referenced by vect_pattern_recog().

static gimple vect_recog_bool_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Function vect_recog_bool_pattern

   Try to find pattern like following:

     bool a_b, b_b, c_b, d_b, e_b;
     TYPE f_T;
   loop:
     S1  a_b = x1 CMP1 y1;
     S2  b_b = x2 CMP2 y2;
     S3  c_b = a_b & b_b;
     S4  d_b = x3 CMP3 y3;
     S5  e_b = c_b | d_b;
     S6  f_T = (TYPE) e_b;

   where type 'TYPE' is an integral type.

   Input:

   * LAST_STMT: A stmt at the end from which the pattern
                search begins, i.e. cast of a bool to
                an integer type.

   Output:

   * TYPE_IN: The type of the input arguments to the pattern.

   * TYPE_OUT: The type of the output of this pattern.

   * Return value: A new stmt that will be used to replace the pattern.

        Assuming size of TYPE is the same as size of all comparisons
        (otherwise some casts would be added where needed), the above
        sequence we create related pattern stmts:
        S1'  a_T = x1 CMP1 y1 ? 1 : 0;
        S3'  c_T = x2 CMP2 y2 ? a_T : 0;
        S4'  d_T = x3 CMP3 y3 ? 1 : 0;
        S5'  e_T = c_T | d_T;
        S6'  f_T = e_T;

        Instead of the above S3' we could emit:
        S2'  b_T = x2 CMP2 y2 ? 1 : 0;
        S3'  c_T = a_T | b_T;
        but the above is more efficient.   

References adjust_bool_pattern(), check_bool_pattern(), DR_STMT, dump_enabled_p(), dump_printf_loc(), get_vectype_for_scalar_type(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), is_gimple_assign(), last_stmt(), new_pattern_def_seq(), new_stmt_vec_info(), set_vinfo_for_stmt(), useless_type_conversion_p(), vect_location, vect_recog_temp_ssa_var(), and vinfo_for_stmt().

static gimple vect_recog_divmod_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Detect a signed division by a constant that wouldn't be
   otherwise vectorized:

   type a_t, b_t;

   S1 a_t = b_t / N;

  where type 'type' is an integral type and N is a constant.

  Similarly handle modulo by a constant:

   S4 a_t = b_t % N;

  Input/Output:

  * STMTS: Contains a stmt from which the pattern search begins,
    i.e. the division stmt.  S1 is replaced by if N is a power
    of two constant and type is signed:
  S3  y_t = b_t < 0 ? N - 1 : 0;
  S2  x_t = b_t + y_t;
  S1' a_t = x_t >> log2 (N);

    S4 is replaced if N is a power of two constant and
    type is signed by (where *_T temporaries have unsigned type):
  S9  y_T = b_t < 0 ? -1U : 0U;
  S8  z_T = y_T >> (sizeof (type_t) * CHAR_BIT - log2 (N));
  S7  z_t = (type) z_T;
  S6  w_t = b_t + z_t;
  S5  x_t = w_t & (N - 1);
  S4' a_t = x_t - z_t;

  Output:

  * TYPE_IN: The type of the input arguments to the pattern.

  * TYPE_OUT: The type of the output of this pattern.

  * Return value: A new stmt that will be used to replace the division
    S1 or modulo S4 stmt.   

References append_pattern_def_seq(), build_int_cst(), build_nonstandard_integer_type(), can_mult_highpart_p(), choose_multiplier(), compare_tree_int(), dump_enabled_p(), dump_gimple_stmt(), dump_gimple_stmt_loc(), dump_printf_loc(), floor_log2(), get_vectype_for_scalar_type(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), HOST_BITS_PER_WIDE_INT, host_integerp(), HOST_WIDE_INT, integer_pow2p(), integer_zerop(), is_gimple_assign(), last_stmt(), new_pattern_def_seq(), new_stmt_vec_info(), optab_default, optab_for_tree_code(), optab_handler(), set_vinfo_for_stmt(), shift, tree_int_cst_sgn(), tree_log2(), tree_low_cst(), unknown_optab, vect_location, vect_recog_temp_ssa_var(), and vinfo_for_stmt().

static gimple vect_recog_dot_prod_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Function vect_recog_dot_prod_pattern

   Try to find the following pattern:

     type x_t, y_t;
     TYPE1 prod;
     TYPE2 sum = init;
   loop:
     sum_0 = phi <init, sum_1>
     S1  x_t = ...
     S2  y_t = ...
     S3  x_T = (TYPE1) x_t;
     S4  y_T = (TYPE1) y_t;
     S5  prod = x_T * y_T;
     [S6  prod = (TYPE2) prod;  #optional]
     S7  sum_1 = prod + sum_0;

   where 'TYPE1' is exactly double the size of type 'type', and 'TYPE2' is the
   same size of 'TYPE1' or bigger. This is a special case of a reduction
   computation.

   Input:

   * STMTS: Contains a stmt from which the pattern search begins.  In the
   example, when this function is called with S7, the pattern {S3,S4,S5,S6,S7}
   will be detected.

   Output:

   * TYPE_IN: The type of the input arguments to the pattern.

   * TYPE_OUT: The type of the output  of this pattern.

   * Return value: A new stmt that will be used to replace the sequence of
   stmts that constitute the pattern. In this case it will be:
        WIDEN_DOT_PRODUCT <x_t, y_t, sum_0>

   Note: The dot-prod idiom is a widening reduction pattern that is
         vectorized without preserving all the intermediate results. It
         produces only N/2 (widened) results (by summing up pairs of
         intermediate results) rather than all N results.  Therefore, we
         cannot allow this pattern when we want to get all the results and in
         the correct order (as is the case when this computation is in an
         inner-loop nested in an outer-loop that us being vectorized).   

References dump_enabled_p(), dump_gimple_stmt(), dump_printf_loc(), flow_bb_inside_loop_p(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), gimple_expr_type(), is_gimple_assign(), last_stmt(), nested_in_vect_loop_p(), type(), type_conversion_p(), types_compatible_p(), vect_internal_def, vect_location, vect_recog_temp_ssa_var(), vect_reduction_def, and vinfo_for_stmt().

static gimple vect_recog_mixed_size_cond_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Function vect_recog_mixed_size_cond_pattern

   Try to find the following pattern:

     type x_t, y_t;
     TYPE a_T, b_T, c_T;
   loop:
     S1  a_T = x_t CMP y_t ? b_T : c_T;

   where type 'TYPE' is an integral type which has different size
   from 'type'.  b_T and c_T are either constants (and if 'TYPE' is wider
   than 'type', the constants need to fit into an integer type
   with the same width as 'type') or results of conversion from 'type'.

   Input:

   * LAST_STMT: A stmt from which the pattern search begins.

   Output:

   * TYPE_IN: The type of the input arguments to the pattern.

   * TYPE_OUT: The type of the output of this pattern.

   * Return value: A new stmt that will be used to replace the pattern.
        Additionally a def_stmt is added.

        a_it = x_t CMP y_t ? b_it : c_it;
        a_T = (TYPE) a_it;   

References build_nonstandard_integer_type(), dump_enabled_p(), dump_printf_loc(), expand_vec_cond_expr_p(), get_vectype_for_scalar_type(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs3(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), gimple_expr_type(), int_fits_type_p(), is_gimple_assign(), last_stmt(), new_pattern_def_seq(), new_stmt_vec_info(), set_vinfo_for_stmt(), type(), type_conversion_p(), types_compatible_p(), unshare_expr(), vect_internal_def, vect_location, vect_recog_temp_ssa_var(), and vinfo_for_stmt().

static gimple vect_recog_over_widening_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Try to find a statement or a sequence of statements that can be performed
   on a smaller type:

     type x_t;
     TYPE x_T, res0_T, res1_T;
   loop:
     S1  x_t = *p;
     S2  x_T = (TYPE) x_t;
     S3  res0_T = op (x_T, C0);
     S4  res1_T = op (res0_T, C1);
     S5  ... = () res1_T;  - type demotion

   where type 'TYPE' is at least double the size of type 'type', C0 and C1 are
   constants.
   Check if S3 and S4 can be done on a smaller type than 'TYPE', it can either
   be 'type' or some intermediate type.  For now, we expect S5 to be a type
   demotion operation.  We also check that S3 and S4 have only one use.   

References dump_enabled_p(), dump_gimple_stmt(), dump_printf_loc(), first, get_vectype_for_scalar_type(), gimple_assign_lhs(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), gimple_expr_type(), is_gimple_assign(), make_ssa_name(), new_pattern_def_seq(), vect_location, vect_operation_fits_smaller_type(), vect_recog_temp_ssa_var(), vect_single_imm_use(), and vinfo_for_stmt().

static gimple vect_recog_pow_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Function vect_recog_pow_pattern

   Try to find the following pattern:

     x = POW (y, N);

   with POW being one of pow, powf, powi, powif and N being
   either 2 or 0.5.

   Input:

   * LAST_STMT: A stmt from which the pattern search begins.

   Output:

   * TYPE_IN: The type of the input arguments to the pattern.

   * TYPE_OUT: The type of the output of this pattern.

   * Return value: A new stmt that will be used to replace the sequence of
   stmts that constitute the pattern. In this case it will be:
        x = x * x
   or
        x = sqrt (x)

References BUILT_IN_NORMAL, dconst2, dconsthalf, exp(), get_vectype_for_scalar_type(), gimple_build_assign_with_ops(), gimple_build_call(), gimple_call_arg(), gimple_call_fndecl(), gimple_call_lhs(), gimple_call_set_lhs(), host_integerp(), is_gimple_call(), last_stmt(), mathfn_built_in(), tree_low_cst(), vect_recog_temp_ssa_var(), and vectorizable_function().

static gimple vect_recog_rotate_pattern ( vec< gimple > *  ,
tree ,
tree  
)
static
static gimple vect_recog_rotate_pattern ( )
static
Detect a rotate pattern wouldn't be otherwise vectorized:

   type a_t, b_t, c_t;

   S0 a_t = b_t r<< c_t;

  Input/Output:

  * STMTS: Contains a stmt from which the pattern search begins,
    i.e. the shift/rotate stmt.  The original stmt (S0) is replaced
    with a sequence:

   S1 d_t = -c_t;
   S2 e_t = d_t & (B - 1);
   S3 f_t = b_t << c_t;
   S4 g_t = b_t >> e_t;
   S0 a_t = f_t | g_t;

    where B is element bitsize of type.

  Output:

  * TYPE_IN: The type of the input arguments to the pattern.

  * TYPE_OUT: The type of the output of this pattern.

  * Return value: A new stmt that will be used to replace the rotate
    S0 stmt.   

References append_pattern_def_seq(), build_int_cst(), CDI_DOMINATORS, edge_def::dest, dominated_by_p(), dump_enabled_p(), dump_gimple_stmt_loc(), dump_printf_loc(), get_vectype_for_scalar_type(), gimple_assign_cast_p(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_bb(), gimple_build_assign_with_ops(), gsi_insert_on_edge_immediate(), host_integerp(), HOST_WIDE_INT, integer_zerop(), is_gimple_assign(), last_stmt(), loop_preheader_edge(), new_stmt_vec_info(), optab_for_tree_code(), optab_handler(), optab_scalar, optab_vector, set_vinfo_for_stmt(), tree_low_cst(), type(), vect_constant_def, vect_external_def, vect_internal_def, vect_is_simple_use(), vect_location, vect_recog_temp_ssa_var(), and vinfo_for_stmt().

static gimple vect_recog_vector_vector_shift_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Detect a vector by vector shift pattern that wouldn't be otherwise
   vectorized:

   type a_t;
   TYPE b_T, res_T;

   S1 a_t = ;
   S2 b_T = ;
   S3 res_T = b_T op a_t;

  where type 'TYPE' is a type with different size than 'type',
  and op is <<, >> or rotate.

  Also detect cases:

   type a_t;
   TYPE b_T, c_T, res_T;

   S0 c_T = ;
   S1 a_t = (type) c_T;
   S2 b_T = ;
   S3 res_T = b_T op a_t;

  Input/Output:

  * STMTS: Contains a stmt from which the pattern search begins,
    i.e. the shift/rotate stmt.  The original stmt (S3) is replaced
    with a shift/rotate which has same type on both operands, in the
    second case just b_T op c_T, in the first case with added cast
    from a_t to c_T in STMT_VINFO_PATTERN_DEF_SEQ.

  Output:

  * TYPE_IN: The type of the input arguments to the pattern.

  * TYPE_OUT: The type of the output of this pattern.

  * Return value: A new stmt that will be used to replace the shift/rotate
    S3 stmt.   

References dump_enabled_p(), dump_gimple_stmt_loc(), dump_printf_loc(), get_vectype_for_scalar_type(), gimple_assign_cast_p(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), is_gimple_assign(), last_stmt(), new_pattern_def_seq(), vect_internal_def, vect_is_simple_use(), vect_location, vect_recog_temp_ssa_var(), and vinfo_for_stmt().

static gimple vect_recog_widen_mult_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Function vect_recog_widen_mult_pattern

   Try to find the following pattern:

     type a_t, b_t;
     TYPE a_T, b_T, prod_T;

     S1  a_t = ;
     S2  b_t = ;
     S3  a_T = (TYPE) a_t;
     S4  b_T = (TYPE) b_t;
     S5  prod_T = a_T * b_T;

   where type 'TYPE' is at least double the size of type 'type'.

   Also detect unsigned cases:

     unsigned type a_t, b_t;
     unsigned TYPE u_prod_T;
     TYPE a_T, b_T, prod_T;

     S1  a_t = ;
     S2  b_t = ;
     S3  a_T = (TYPE) a_t;
     S4  b_T = (TYPE) b_t;
     S5  prod_T = a_T * b_T;
     S6  u_prod_T = (unsigned TYPE) prod_T;

   and multiplication by constants:

     type a_t;
     TYPE a_T, prod_T;

     S1  a_t = ;
     S3  a_T = (TYPE) a_t;
     S5  prod_T = a_T * CONST;

   A special case of multiplication by constants is when 'TYPE' is 4 times
   bigger than 'type', but CONST fits an intermediate type 2 times smaller
   than 'TYPE'.  In that case we create an additional pattern stmt for S3
   to create a variable of the intermediate type, and perform widen-mult
   on the intermediate type as well:

     type a_t;
     interm_type a_it;
     TYPE a_T, prod_T,  prod_T';

     S1  a_t = ;
     S3  a_T = (TYPE) a_t;
           '--> a_it = (interm_type) a_t;
     S5  prod_T = a_T * CONST;
           '--> prod_T' = a_it w* CONST;

   Input/Output:

   * STMTS: Contains a stmt from which the pattern search begins.  In the
   example, when this function is called with S5, the pattern {S3,S4,S5,(S6)}
   is detected.  In case of unsigned widen-mult, the original stmt (S5) is
   replaced with S6 in STMTS.  In case of multiplication by a constant
   of an intermediate type (the last case above), STMTS also contains S3
   (inserted before S5).

   Output:

   * TYPE_IN: The type of the input arguments to the pattern.

   * TYPE_OUT: The type of the output of this pattern.

   * Return value: A new stmt that will be used to replace the sequence of
   stmts that constitute the pattern.  In this case it will be:
        WIDEN_MULT <a_t, b_t>

References dump_enabled_p(), dump_gimple_stmt_loc(), dump_printf_loc(), get_vectype_for_scalar_type(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), gimple_expr_type(), is_gimple_assign(), last_stmt(), supportable_widening_operation(), type(), type_conversion_p(), types_compatible_p(), vect_handle_widen_op_by_const(), vect_location, vect_recog_temp_ssa_var(), and vect_single_imm_use().

static gimple vect_recog_widen_shift_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
Detect widening shift pattern:

   type a_t;
   TYPE a_T, res_T;

   S1 a_t = ;
   S2 a_T = (TYPE) a_t;
   S3 res_T = a_T << CONST;

  where type 'TYPE' is at least double the size of type 'type'.

  Also detect cases where the shift result is immediately converted
  to another type 'result_type' that is no larger in size than 'TYPE'.
  In those cases we perform a widen-shift that directly results in
  'result_type', to avoid a possible over-widening situation:

  type a_t;
  TYPE a_T, res_T;
  result_type res_result;

  S1 a_t = ;
  S2 a_T = (TYPE) a_t;
  S3 res_T = a_T << CONST;
  S4 res_result = (result_type) res_T;
      '--> res_result' = a_t w<< CONST;

  And a case when 'TYPE' is 4 times bigger than 'type'.  In that case we
  create an additional pattern stmt for S2 to create a variable of an
  intermediate type, and perform widen-shift on the intermediate type:

  type a_t;
  interm_type a_it;
  TYPE a_T, res_T, res_T';

  S1 a_t = ;
  S2 a_T = (TYPE) a_t;
      '--> a_it = (interm_type) a_t;
  S3 res_T = a_T << CONST;
      '--> res_T' = a_it <<* CONST;

  Input/Output:

  * STMTS: Contains a stmt from which the pattern search begins.
    In case of unsigned widen-shift, the original stmt (S3) is replaced with S4
    in STMTS.  When an intermediate type is used and a pattern statement is
    created for S2, we also put S2 here (before S3).

  Output:

  * TYPE_IN: The type of the input arguments to the pattern.

  * TYPE_OUT: The type of the output of this pattern.

  * Return value: A new stmt that will be used to replace the sequence of
    stmts that constitute the pattern.  In this case it will be:
    WIDEN_LSHIFT_EXPR <a_t, CONST>.   

References dump_enabled_p(), dump_gimple_stmt_loc(), dump_printf_loc(), get_vectype_for_scalar_type(), gimple_assign_lhs(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), gimple_expr_type(), is_gimple_assign(), last_stmt(), supportable_widening_operation(), tree_int_cst_compare(), type(), type_conversion_p(), vect_handle_widen_op_by_const(), vect_location, vect_recog_temp_ssa_var(), vect_single_imm_use(), and vinfo_for_stmt().

static gimple vect_recog_widen_sum_pattern ( vec< gimple > *  stmts,
tree type_in,
tree type_out 
)
static
@verbatim Analysis Utilities for Loop Vectorization.

Copyright (C) 2006-2013 Free Software Foundation, Inc. Contributed by Dorit Nuzman dorit.nosp@m.@il..nosp@m.ibm.c.nosp@m.om

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see http://www.gnu.org/licenses/.

Pattern recognition functions   
Function vect_recog_widen_sum_pattern

   Try to find the following pattern:

     type x_t;
     TYPE x_T, sum = init;
   loop:
     sum_0 = phi <init, sum_1>
     S1  x_t = *p;
     S2  x_T = (TYPE) x_t;
     S3  sum_1 = x_T + sum_0;

   where type 'TYPE' is at least double the size of type 'type', i.e - we're
   summing elements of type 'type' into an accumulator of type 'TYPE'. This is
   a special case of a reduction computation.

   Input:

   * LAST_STMT: A stmt from which the pattern search begins. In the example,
   when this function is called with S3, the pattern {S2,S3} will be detected.

   Output:

   * TYPE_IN: The type of the input arguments to the pattern.

   * TYPE_OUT: The type of the output of this pattern.

   * Return value: A new stmt that will be used to replace the sequence of
   stmts that constitute the pattern. In this case it will be:
        WIDEN_SUM <x_t, sum_0>

   Note: The widening-sum idiom is a widening reduction pattern that is
         vectorized without preserving all the intermediate results. It
         produces only N/2 (widened) results (by summing up pairs of
         intermediate results) rather than all N results.  Therefore, we
         cannot allow this pattern when we want to get all the results and in
         the correct order (as is the case when this computation is in an
         inner-loop nested in an outer-loop that us being vectorized).   

References dump_enabled_p(), dump_gimple_stmt(), dump_printf_loc(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_build_assign_with_ops(), gimple_expr_type(), is_gimple_assign(), last_stmt(), nested_in_vect_loop_p(), type(), type_conversion_p(), types_compatible_p(), vect_location, vect_recog_temp_ssa_var(), vect_reduction_def, and vinfo_for_stmt().

static bool vect_same_loop_or_bb_p ( )
static
Check whether STMT2 is in the same loop or basic block as STMT1.
   Which of the two applies depends on whether we're currently doing
   loop-based or basic-block-based vectorization, as determined by
   the vinfo_for_stmt for STMT1 (which must be defined).

   If this returns true, vinfo_for_stmt for STMT2 is guaranteed
   to be defined as well.   

References flow_bb_inside_loop_p(), and vinfo_for_stmt().

Referenced by vect_handle_widen_op_by_const(), vect_operation_fits_smaller_type(), and vect_single_imm_use().

static gimple vect_single_imm_use ( )
static
If the LHS of DEF_STMT has a single use, and that statement is
   in the same loop or basic block, return it.   

References gimple_assign_lhs(), single_imm_use(), and vect_same_loop_or_bb_p().

Referenced by vect_recog_over_widening_pattern(), vect_recog_widen_mult_pattern(), and vect_recog_widen_shift_pattern().


Variable Documentation