re PR middle-end/55481 (-O2 generates a wrong-code infinite loop in C++Benchmark's simple_types_constant_folding int8 xor test)
2012-12-12 Zdenek Dvorak <ook@ucw.cz> PR tree-optimization/55481 * tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr): Fall back to general rewriting if we cannot leave an original biv definition alone. * gcc.dg/torture/pr55481.c: New testcase. From-SVN: r194444
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2012-12-12 Zdenek Dvorak <ook@ucw.cz>
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PR tree-optimization/55481
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* tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr): Fall
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back to general rewriting if we cannot leave an original biv
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definition alone.
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2012-12-12 Jakub Jelinek <jakub@redhat.com>
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PR target/55659
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@ -1,3 +1,8 @@
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2012-12-12 Zdenek Dvorak <ook@ucw.cz>
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PR tree-optimization/55481
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* gcc.dg/torture/pr55481.c: New testcase.
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2012-12-12 Steven Bosscher <steven@gcc.gnu.org>
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Jakub Jelinek <jakub@redhat.com>
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/* { dg-do run } */
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int main()
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{
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signed char result = 0;
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int n;
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for (n = 0; n < 13; ++n)
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{
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int tem = result;
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tem = tem + 31;
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result = tem;
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}
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if (result != -109)
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__builtin_abort ();
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return 0;
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}
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@ -6088,35 +6088,24 @@ rewrite_use_nonlinear_expr (struct ivopts_data *data,
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if (cand->pos == IP_ORIGINAL
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&& cand->incremented_at == use->stmt)
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{
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tree step, ctype, utype;
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enum tree_code incr_code = PLUS_EXPR, old_code;
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enum tree_code stmt_code;
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gcc_assert (is_gimple_assign (use->stmt));
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gcc_assert (gimple_assign_lhs (use->stmt) == cand->var_after);
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step = cand->iv->step;
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ctype = TREE_TYPE (step);
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utype = TREE_TYPE (cand->var_after);
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if (TREE_CODE (step) == NEGATE_EXPR)
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{
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incr_code = MINUS_EXPR;
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step = TREE_OPERAND (step, 0);
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}
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/* Check whether we may leave the computation unchanged.
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This is the case only if it does not rely on other
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computations in the loop -- otherwise, the computation
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we rely upon may be removed in remove_unused_ivs,
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thus leading to ICE. */
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old_code = gimple_assign_rhs_code (use->stmt);
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if (old_code == PLUS_EXPR
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|| old_code == MINUS_EXPR
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|| old_code == POINTER_PLUS_EXPR)
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stmt_code = gimple_assign_rhs_code (use->stmt);
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if (stmt_code == PLUS_EXPR
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|| stmt_code == MINUS_EXPR
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|| stmt_code == POINTER_PLUS_EXPR)
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{
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if (gimple_assign_rhs1 (use->stmt) == cand->var_before)
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op = gimple_assign_rhs2 (use->stmt);
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else if (old_code != MINUS_EXPR
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&& gimple_assign_rhs2 (use->stmt) == cand->var_before)
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else if (gimple_assign_rhs2 (use->stmt) == cand->var_before)
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op = gimple_assign_rhs1 (use->stmt);
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else
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op = NULL_TREE;
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@ -6124,23 +6113,12 @@ rewrite_use_nonlinear_expr (struct ivopts_data *data,
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else
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op = NULL_TREE;
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if (op
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&& (TREE_CODE (op) == INTEGER_CST
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|| operand_equal_p (op, step, 0)))
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if (op && expr_invariant_in_loop_p (data->current_loop, op))
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return;
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}
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/* Otherwise, add the necessary computations to express
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the iv. */
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op = fold_convert (ctype, cand->var_before);
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comp = fold_convert (utype,
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build2 (incr_code, ctype, op,
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unshare_expr (step)));
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}
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else
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{
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comp = get_computation (data->current_loop, use, cand);
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gcc_assert (comp != NULL_TREE);
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}
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comp = get_computation (data->current_loop, use, cand);
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gcc_assert (comp != NULL_TREE);
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switch (gimple_code (use->stmt))
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{
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