On 2020/4/28 15:01, Richard Biener wrote:
> On Tue, 28 Apr 2020, Xionghu Luo wrote:
>
>> From: Xionghu Luo <luo...@linux.ibm.com>
>>
>> Get and propagate value range info to convert expressions with convert
>> operation on PLUS_EXPR/MINUS_EXPR/MULT_EXPR when not overflow. i.e.:
>>
>> (long unsigned int)((unsigned int)n * 10 + 1)
>> =>
>> (long unsigned int)((unsigned int) n * (long unsigned int)10 + (long
>> unsigned int)1)
>>
>> With this patch for affine combination, load/store motion could detect
>> more address refs independency and promote some memory expressions to
>> registers within loop.
>>
>> PS: Replace the previous "(T1)(X + CST) as (T1)X - (T1)(-CST))"
>> to "(T1)(X + CST) as (T1)X + (T1)(CST))" for wrapping overflow.
>>
>> Bootstrap and regression tested pass on Power8-LE. Any comments?
>> Thanks.
>
> So the core of the patch is adding handling of MULT_EXPR and the rest
> is a no-op? It's not clear from the patch what passing down a
> value-range does and your description doesn't say anything about this
> either.
This patch handles MULT_EXPR first, and also handles (long unsigned int)(n_93 *
10 + 1) as
"n_93*10" is not a ssa_name by using the value_range passed down, minv&maxv
[1,81] is the
range info of "n_93 * 10 +1", so wi::leu_p (maxv, wi::to_wide (TYPE_MAX_VALUE
(itype)) in
expr_to_aff_combination could ensure that no wrapping overflow of this
converting. Not sure
if it's better described now... And some debug message as follows:
131t.lim2:
# n_93 = PHI <0(2), n_36(7)>
_118 = n_93 * 10;
_120 = (long unsigned int) _118;
_121 = _120 * 8;
_122 = &C[0][0] + _121;
*_122 = 0.0;
_128 = _118 + 1;
_129 = (long unsigned int) _128;
_130 = _129 * 8;
_131 = &C[0][0] + _130;
*_131 = 0.0;
_137 = _118 + 2;
_138 = (long unsigned int) _137;
_139 = _138 * 8;
_140 = &C[0][0] + _139;
*_140 = 0.0;
Breakpoint 28, expr_to_aff_combination (comb=0x7fffffffc068, code=NOP_EXPR,
type=<integer_type 0x7ffff53c07
e0 long unsigned int>, op0=<plus_expr 0x7ffff56c0988>, op1=<tree 0x0>,
vr=0x7fffffffc490) at ../../gcc-mast
er/gcc/tree-affine.c:350
92: itype = <integer_type 0x7ffff53c0690 unsigned int>
93: otype = <integer_type 0x7ffff53c07e0 long unsigned int>
94: icode = PLUS_EXPR
95: code = NOP_EXPR
(gdb) ptree op0
<mult_expr 0x7ffff56c0960
type <integer_type 0x7ffff53c0690 unsigned int sizes-gimplified public
unsigned SI
size <integer_cst 0x7ffff52f1200 constant 32>
unit-size <integer_cst 0x7ffff52f1218 constant 4>
align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff53c0690 precision:32 min <
integer_cst 0x7ffff52f1230 0> max <integer_cst 0x7ffff52f11e8 4294967295>
context <translation_unit_decl 0x
7ffff5552850 pr83403.c>
pointer_to_this <pointer_type 0x7ffff53c4c20>>
arg:0 <ssa_name 0x7ffff5394a88 type <integer_type 0x7ffff53c0690 unsigned
int>
visited var <var_decl 0x7ffff72e2520 n>
def_stmt n_93 = PHI <0(2), n_36(7)>
version:93
ptr-info 0x7ffff530b680>
arg:1 <integer_cst 0x7ffff52feda8 type <integer_type 0x7ffff53c0690
unsigned int> constant 10>>
(gdb) ptree op1
<integer_cst 0x7ffff52fed48 type <integer_type 0x7ffff53c0690 unsigned int>
constant 1>
(gdb) p minv
$580 = {
<wide_int_storage> = {
val = {1, 0, 140737310886240},
len = 1,
precision = 32
},
members of generic_wide_int<wide_int_storage>:
static is_sign_extended = true
}
(gdb) p maxv
$581 = {
<wide_int_storage> = {
val = {81, 65, 40},
len = 1,
precision = 32
},
members of generic_wide_int<wide_int_storage>:
static is_sign_extended = true
}
Thanks,
Xionghu
>
> Richard.
>
>> gcc/ChangeLog
>>
>> 2020-04-28 Xiong Hu Luo <luo...@linux.ibm.com>
>>
>> PR tree-optimization/83403
>> * tree-affine.c (aff_combination_convert): New parameter
>> value_range.
>> (expr_to_aff_combination): Use range info to check CONVERT
>> expr on PLUS_EXPR/MINUS_EXPR/MULT_EXPR.
>> (tree_to_aff_combination): Likewise.
>> (aff_combination_expand): Get and propagate range info.
>> * tree-affine.h: Include value-range.h.
>> (aff_combination_convert): New parameter value_range.
>> (tree_to_aff_combination): Likewise.
>> (aff_combination_expand): Likewise.
>> ---
>> gcc/tree-affine.c | 66 +++++++++++++++++++++++++++--------------------
>> gcc/tree-affine.h | 8 +++---
>> 2 files changed, 43 insertions(+), 31 deletions(-)
>>
>> diff --git a/gcc/tree-affine.c b/gcc/tree-affine.c
>> index 0eb8db1b086..63f8acd4c73 100644
>> --- a/gcc/tree-affine.c
>> +++ b/gcc/tree-affine.c
>> @@ -220,7 +220,7 @@ aff_combination_add (aff_tree *comb1, aff_tree *comb2)
>> /* Converts affine combination COMB to TYPE. */
>>
>> void
>> -aff_combination_convert (aff_tree *comb, tree type)
>> +aff_combination_convert (aff_tree *comb, tree type, value_range *vr)
>> {
>> unsigned i, j;
>> tree comb_type = comb->type;
>> @@ -228,7 +228,7 @@ aff_combination_convert (aff_tree *comb, tree type)
>> if (TYPE_PRECISION (type) > TYPE_PRECISION (comb_type))
>> {
>> tree val = fold_convert (type, aff_combination_to_tree (comb));
>> - tree_to_aff_combination (val, type, comb);
>> + tree_to_aff_combination (val, type, comb, vr);
>> return;
>> }
>>
>> @@ -263,8 +263,8 @@ aff_combination_convert (aff_tree *comb, tree type)
>> true when that was successful and returns the combination in COMB. */
>>
>> static bool
>> -expr_to_aff_combination (aff_tree *comb, tree_code code, tree type,
>> - tree op0, tree op1 = NULL_TREE)
>> +expr_to_aff_combination (aff_tree *comb, tree_code code, tree type, tree
>> op0,
>> + tree op1 = NULL_TREE, value_range *vr = NULL)
>> {
>> aff_tree tmp;
>> poly_int64 bitpos, bitsize, bytepos;
>> @@ -279,8 +279,8 @@ expr_to_aff_combination (aff_tree *comb, tree_code code,
>> tree type,
>>
>> case PLUS_EXPR:
>> case MINUS_EXPR:
>> - tree_to_aff_combination (op0, type, comb);
>> - tree_to_aff_combination (op1, type, &tmp);
>> + tree_to_aff_combination (op0, type, comb, vr);
>> + tree_to_aff_combination (op1, type, &tmp, vr);
>> if (code == MINUS_EXPR)
>> aff_combination_scale (&tmp, -1);
>> aff_combination_add (comb, &tmp);
>> @@ -289,7 +289,7 @@ expr_to_aff_combination (aff_tree *comb, tree_code code,
>> tree type,
>> case MULT_EXPR:
>> if (TREE_CODE (op1) != INTEGER_CST)
>> break;
>> - tree_to_aff_combination (op0, type, comb);
>> + tree_to_aff_combination (op0, type, comb, vr);
>> aff_combination_scale (comb, wi::to_widest (op1));
>> return true;
>>
>> @@ -340,27 +340,33 @@ expr_to_aff_combination (aff_tree *comb, tree_code
>> code, tree type,
>> op1 = fold_convert (otype, op1);
>> return expr_to_aff_combination (comb, icode, otype, op0, op1);
>> }
>> - wide_int minv, maxv;
>> +
>> /* If inner type has wrapping overflow behavior, fold conversion
>> - for below case:
>> - (T1)(X - CST) -> (T1)X - (T1)CST
>> - if X - CST doesn't overflow by range information. Also handle
>> - (T1)(X + CST) as (T1)(X - (-CST)). */
>> - if (TYPE_UNSIGNED (itype)
>> + for below cases:
>> + (T1)(X *+- CST) -> (T1)X *+- (T1)CST
>> + when X *+- CST doesn't overflow by range information. */
>> + if (vr && vr->kind () == VR_RANGE && TYPE_UNSIGNED (itype)
>> && TYPE_OVERFLOW_WRAPS (itype)
>> - && TREE_CODE (op0) == SSA_NAME
>> - && TREE_CODE (op1) == INTEGER_CST
>> - && icode != MULT_EXPR
>> - && get_range_info (op0, &minv, &maxv) == VR_RANGE)
>> + && TREE_CODE (op1) == INTEGER_CST)
>> {
>> - if (icode == PLUS_EXPR)
>> - op1 = wide_int_to_tree (itype, -wi::to_wide (op1));
>> - if (wi::geu_p (minv, wi::to_wide (op1)))
>> + wide_int minv, maxv;
>> + minv = wi::to_wide (vr->min ());
>> + maxv = wi::to_wide (vr->max ());
>> + if ((icode == MULT_EXPR || icode == PLUS_EXPR)
>> + && wi::leu_p (maxv, wi::to_wide (TYPE_MAX_VALUE (itype))))
>> + {
>> + op0 = fold_convert (otype, op0);
>> + op1 = fold_convert (otype, op1);
>> + return expr_to_aff_combination (comb, icode, otype, op0,
>> + op1, vr);
>> + }
>> + else if (icode == MINUS_EXPR
>> + && wi::geu_p (minv, wi::to_wide (op1)))
>> {
>> op0 = fold_convert (otype, op0);
>> op1 = fold_convert (otype, op1);
>> return expr_to_aff_combination (comb, MINUS_EXPR, otype,
>> - op0, op1);
>> + op0, op1, vr);
>> }
>> }
>> }
>> @@ -376,7 +382,7 @@ expr_to_aff_combination (aff_tree *comb, tree_code code,
>> tree type,
>> /* Splits EXPR into an affine combination of parts. */
>>
>> void
>> -tree_to_aff_combination (tree expr, tree type, aff_tree *comb)
>> +tree_to_aff_combination (tree expr, tree type, aff_tree *comb, value_range
>> *vr)
>> {
>> aff_tree tmp;
>> enum tree_code code;
>> @@ -408,10 +414,10 @@ tree_to_aff_combination (tree expr, tree type,
>> aff_tree *comb)
>> CASE_CONVERT:
>> /* ??? TREE_TYPE (expr) should be equal to type here, but IVOPTS
>> calls this with not showing an outer widening cast. */
>> - if (expr_to_aff_combination (comb, code,
>> - TREE_TYPE (expr), TREE_OPERAND (expr, 0)))
>> + if (expr_to_aff_combination (comb, code, TREE_TYPE (expr),
>> + TREE_OPERAND (expr, 0), NULL_TREE, vr))
>> {
>> - aff_combination_convert (comb, type);
>> + aff_combination_convert (comb, type, vr);
>> return;
>> }
>> break;
>> @@ -709,7 +715,8 @@ public:
>>
>> void
>> aff_combination_expand (aff_tree *comb ATTRIBUTE_UNUSED,
>> - hash_map<tree, name_expansion *> **cache)
>> + hash_map<tree, name_expansion *> **cache,
>> + value_range *vr)
>> {
>> unsigned i;
>> aff_tree to_add, current, curre;
>> @@ -800,7 +807,10 @@ aff_combination_expand (aff_tree *comb ATTRIBUTE_UNUSED,
>> if (!*cache)
>> *cache = new hash_map<tree, name_expansion *>;
>> (*cache)->put (name, exp);
>> - aff_combination_expand (¤t, cache);
>> + value_range vr = NULL;
>> + if (!POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (def))))
>> + get_range_info (gimple_assign_rhs1 (def), vr);
>> + aff_combination_expand (¤t, cache, &vr);
>> exp->expansion = current;
>> exp->in_progress = 0;
>> }
>> @@ -812,7 +822,7 @@ aff_combination_expand (aff_tree *comb ATTRIBUTE_UNUSED,
>> current = exp->expansion;
>> }
>> if (!useless_type_conversion_p (comb->type, current.type))
>> - aff_combination_convert (¤t, comb->type);
>> + aff_combination_convert (¤t, comb->type, vr);
>>
>> /* Accumulate the new terms to TO_ADD, so that we do not modify
>> COMB while traversing it; include the term -coef * E, to remove
>> diff --git a/gcc/tree-affine.h b/gcc/tree-affine.h
>> index 4ec4924879d..311e5e7c23a 100644
>> --- a/gcc/tree-affine.h
>> +++ b/gcc/tree-affine.h
>> @@ -23,6 +23,7 @@ along with GCC; see the file COPYING3. If not see
>> #ifndef GCC_TREE_AFFINE_H
>> #define GCC_TREE_AFFINE_H
>>
>> +#include "value-range.h"
>>
>> #define MAX_AFF_ELTS 8
>>
>> @@ -73,13 +74,14 @@ void aff_combination_mult (aff_tree *, aff_tree *,
>> aff_tree *);
>> void aff_combination_add (aff_tree *, aff_tree *);
>> void aff_combination_add_elt (aff_tree *, tree, const widest_int &);
>> void aff_combination_remove_elt (aff_tree *, unsigned);
>> -void aff_combination_convert (aff_tree *, tree);
>> -void tree_to_aff_combination (tree, tree, aff_tree *);
>> +void aff_combination_convert (aff_tree *, tree, value_range *vr = NULL);
>> +void tree_to_aff_combination (tree, tree, aff_tree *, value_range *vr =
>> NULL);
>> tree aff_combination_to_tree (aff_tree *);
>> void unshare_aff_combination (aff_tree *);
>> bool aff_combination_constant_multiple_p (aff_tree *, aff_tree *,
>> poly_widest_int *);
>> -void aff_combination_expand (aff_tree *, hash_map<tree, name_expansion *>
>> **);
>> +void aff_combination_expand (aff_tree *, hash_map<tree, name_expansion *>
>> **,
>> + value_range *vr = NULL);
>> void tree_to_aff_combination_expand (tree, tree, aff_tree *,
>> hash_map<tree, name_expansion *> **);
>> tree get_inner_reference_aff (tree, aff_tree *, poly_widest_int *);
>>
>
