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re PR tree-optimization/15784 (fold misses binary optimization)

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PR tree-optimization/15784
        * fold-const.c (fold): Fold ~A + 1 to -A.  Fold -A - 1
        and -1 - A to ~A.


        * stmt.c (expand_case): Don't change index_type.  Convert minval
        to the proper type.

From-SVN: r96289
This commit is contained in:
Jeff Law 2005-03-10 21:52:42 -07:00
parent c0cbd60130
commit cbefb99c99
3 changed files with 26 additions and 5 deletions
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11
gcc/ChangeLog
View file

@ -1,5 +1,12 @@
2005-03-11 James A. Morrison <phython@gcc.gnu.org>
PR tree-optimization/15784
* fold-const.c (fold): Fold ~A + 1 to -A. Fold -A - 1
and -1 - A to ~A.
* stmt.c (expand_case): Don't change index_type. Convert minval
to the proper type.
PR tree-optimization/20130
* fold-const.c (fold): Fold x * -1 into -x.
@ -722,7 +729,7 @@
Revert for now:
2005-03-03 James A. Morrison <phython@gcc.gnu.org>
PR tree-optimization/15784
* fold-const.c (fold): Fold ~A + 1 to -1. Fold -A - 1
* fold-const.c (fold): Fold ~A + 1 to -A. Fold -A - 1
and -1 - A to ~A.
2005-03-04 Ben Elliston <bje@au.ibm.com>
@ -756,7 +763,7 @@
2005-03-03 James A. Morrison <phython@gcc.gnu.org>
PR tree-optimization/15784
* fold-const.c (fold): Fold ~A + 1 to -1. Fold -A - 1
* fold-const.c (fold): Fold ~A + 1 to -A. Fold -A - 1
and -1 - A to ~A.
2005-03-03 David Edelsohn <edelsohn@gnu.org>

15
gcc/fold-const.c
View file

@ -7198,6 +7198,11 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
if (TREE_CODE (arg0) == NEGATE_EXPR
&& reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
/* Convert ~A + 1 to -A. */
if (INTEGRAL_TYPE_P (type)
&& TREE_CODE (arg0) == BIT_NOT_EXPR
&& integer_onep (arg1))
return fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0)));
if (TREE_CODE (type) == COMPLEX_TYPE)
{
@ -7636,6 +7641,16 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
&& reorder_operands_p (arg0, arg1))
return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
TREE_OPERAND (arg0, 0)));
/* Convert -A - 1 to ~A. */
if (INTEGRAL_TYPE_P (type)
&& TREE_CODE (arg0) == NEGATE_EXPR
&& integer_onep (arg1))
return fold (build1 (BIT_NOT_EXPR, type, TREE_OPERAND (arg0, 0)));
/* Convert -1 - A to ~A. */
if (INTEGRAL_TYPE_P (type)
&& integer_all_onesp (arg0))
return fold (build1 (BIT_NOT_EXPR, type, arg1));
if (TREE_CODE (type) == COMPLEX_TYPE)
{

5
gcc/stmt.c
View file

@ -2424,7 +2424,7 @@ expand_case (tree exp)
if (compare_tree_int (minval, 0) > 0
&& compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0)
{
minval = integer_zero_node;
minval = fold_convert (index_type, integer_zero_node);
range = maxval;
}
emit_case_bit_tests (index_type, index_expr, minval, range,
@ -2502,7 +2502,6 @@ expand_case (tree exp)
table_label, default_label))
{
bool ok;
index_type = integer_type_node;
/* Index jumptables from zero for suitable values of
minval to avoid a subtraction. */
@ -2510,7 +2509,7 @@ expand_case (tree exp)
&& compare_tree_int (minval, 0) > 0
&& compare_tree_int (minval, 3) < 0)
{
minval = integer_zero_node;
minval = fold_convert (index_type, integer_zero_node);
range = maxval;
}