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re PR middle-end/9707 (Unnecessary range test in switches with less than 4 cases)

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PR optimization/9707.
	* stmt.c (emit_case_nodes): Emit equality comparisons instead
	of recursing if both children are single-valued cases with no
	children.

From-SVN: r79954
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Kazu Hirata 2004-03-25 16:16:41 +00:00 • committed by Kazu Hirata
parent 6d11af89b1
commit 43a21dfc46
2 changed files with 43 additions and 0 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2004-03-25 Kazu Hirata <kazu@cs.umass.edu>
PR optimization/9707.
* stmt.c (emit_case_nodes): Emit equality comparisons instead
of recursing if both children are single-valued cases with no
children.
2004-03-25 Paul Brook <paul@codesourcery.com>
* config/arm/arm.c (vfp_print_multi): Remove.

36
gcc/stmt.c
View file

@ -6200,6 +6200,42 @@ emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
emit_case_nodes (index, node->right, default_label, index_type);
}
/* If both children are single-valued cases with no
children, finish up all the work. This way, we can save
one ordered comparison. */
else if (tree_int_cst_equal (node->right->low, node->right->high)
&& node->right->left == 0
&& node->right->right == 0
&& tree_int_cst_equal (node->left->low, node->left->high)
&& node->left->left == 0
&& node->left->right == 0)
{
/* Neither node is bounded. First distinguish the two sides;
then emit the code for one side at a time. */
/* See if the value matches what the right hand side
wants. */
do_jump_if_equal (index,
convert_modes (mode, imode,
expand_expr (node->right->low,
NULL_RTX,
VOIDmode, 0),
unsignedp),
label_rtx (node->right->code_label),
unsignedp);
/* See if the value matches what the left hand side
wants. */
do_jump_if_equal (index,
convert_modes (mode, imode,
expand_expr (node->left->low,
NULL_RTX,
VOIDmode, 0),
unsignedp),
label_rtx (node->left->code_label),
unsignedp);
}
else
{
/* Neither node is bounded. First distinguish the two sides;