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| author | Richard Biener <rguenther@suse.de> | 2016-07-13 13:57:05 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-07-13 13:57:05 +0000 |
| commit | 9737f35bba5f6dd73a19b8877ecf5b4fc37b7921 (patch) | |
| tree | 743755983303d6111684311ede069768ee2eb566 /gcc/tree-ssa-phiopt.c | |
| parent | 62c0ea4b14d5cc56b9a2a4c85f8d77f136434680 (diff) | |
| download | gcc-9737f35bba5f6dd73a19b8877ecf5b4fc37b7921.zip gcc-9737f35bba5f6dd73a19b8877ecf5b4fc37b7921.tar.gz gcc-9737f35bba5f6dd73a19b8877ecf5b4fc37b7921.tar.bz2 | |
re PR tree-optimization/24574 (a!=0?a/10:0 is not reduced to a/10)
2016-07-13 Richard Biener <rguenther@suse.de>
PR tree-optimization/24574
* tree-ssa-phiopt.c (absorbing_element_p): Pass in argument
position and add shift, rotate, divison and modulo support
for left zero.
(value_replacement): Pass in argument position to absorbing_element_p.
* gcc.dg/pr24574.c: New testcase.
From-SVN: r238299
Diffstat (limited to 'gcc/tree-ssa-phiopt.c')
| -rw-r--r-- | gcc/tree-ssa-phiopt.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c index caf591b..dd9aa01 100644 --- a/gcc/tree-ssa-phiopt.c +++ b/gcc/tree-ssa-phiopt.c @@ -812,7 +812,7 @@ neutral_element_p (tree_code code, tree arg, bool right) /* Returns true if ARG is an absorbing element for operation CODE. */ static bool -absorbing_element_p (tree_code code, tree arg) +absorbing_element_p (tree_code code, tree arg, bool right) { switch (code) { @@ -823,6 +823,21 @@ absorbing_element_p (tree_code code, tree arg) case BIT_AND_EXPR: return integer_zerop (arg); + case LSHIFT_EXPR: + case RSHIFT_EXPR: + case LROTATE_EXPR: + case RROTATE_EXPR: + case TRUNC_DIV_EXPR: + case CEIL_DIV_EXPR: + case FLOOR_DIV_EXPR: + case ROUND_DIV_EXPR: + case EXACT_DIV_EXPR: + case TRUNC_MOD_EXPR: + case CEIL_MOD_EXPR: + case FLOOR_MOD_EXPR: + case ROUND_MOD_EXPR: + return !right && integer_zerop (arg); + default: return false; } @@ -994,9 +1009,10 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, && operand_equal_for_phi_arg_p (rhs1, cond_lhs) && neutral_element_p (code_def, cond_rhs, false)) || (operand_equal_for_phi_arg_p (arg1, cond_rhs) - && (operand_equal_for_phi_arg_p (rhs2, cond_lhs) - || operand_equal_for_phi_arg_p (rhs1, cond_lhs)) - && absorbing_element_p (code_def, cond_rhs)))) + && ((operand_equal_for_phi_arg_p (rhs2, cond_lhs) + && absorbing_element_p (code_def, cond_rhs, true)) + || (operand_equal_for_phi_arg_p (rhs1, cond_lhs) + && absorbing_element_p (code_def, cond_rhs, false)))))) { gsi = gsi_for_stmt (cond); if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))) |