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stmt.c (expand_case): Put an assertion that index_expr is never INTEGER_CST.

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* stmt.c (expand_case): Put an assertion that index_expr is
	never INTEGER_CST.  Don't special case for constant
	index_expr.

From-SVN: r89590
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Kazu Hirata 2004-10-26 17:19:39 +00:00 committed by Kazu Hirata
parent a3f164bd03
commit 5100d1143a
2 changed files with 26 additions and 47 deletions
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gcc/ChangeLog
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@ -1,3 +1,9 @@
2004-10-26 Kazu Hirata <kazu@cs.umass.edu>
* stmt.c (expand_case): Put an assertion that index_expr is
never INTEGER_CST. Don't special case for constant
index_expr.
2004-10-26 Andrew Pinski <pinskia@physics.uc.edu>
PR 18162

67
gcc/stmt.c
View File

@ -2355,6 +2355,10 @@ expand_case (tree exp)
{
tree elt;
/* cleanup_tree_cfg removes all SWITCH_EXPR with their index
expressions being INTEGER_CST. */
gcc_assert (TREE_CODE (index_expr) != INTEGER_CST);
/* The default case is at the end of TREE_VEC. */
elt = TREE_VEC_ELT (vec, TREE_VEC_LENGTH (vec) - 1);
gcc_assert (!CASE_HIGH (elt));
@ -2494,58 +2498,27 @@ expand_case (tree exp)
if (MEM_P (index))
index = copy_to_reg (index);
if (GET_CODE (index) == CONST_INT
|| TREE_CODE (index_expr) == INTEGER_CST)
{
/* Make a tree node with the proper constant value
if we don't already have one. */
if (TREE_CODE (index_expr) != INTEGER_CST)
{
index_expr
= build_int_cst_wide (NULL_TREE, INTVAL (index),
unsignedp || INTVAL (index) >= 0
? 0 : -1);
index_expr = convert (index_type, index_expr);
}
/* For constant index expressions we need only
issue an unconditional branch to the appropriate
target code. The job of removing any unreachable
code is left to the optimization phase if the
"-O" option is specified. */
for (n = case_list; n; n = n->right)
if (! tree_int_cst_lt (index_expr, n->low)
&& ! tree_int_cst_lt (n->high, index_expr))
break;
/* If the index expression is not constant we generate
a binary decision tree to select the appropriate
target code. This is done as follows:
if (n)
emit_jump (label_rtx (n->code_label));
else
emit_jump (default_label);
}
else
{
/* If the index expression is not constant we generate
a binary decision tree to select the appropriate
target code. This is done as follows:
The list of cases is rearranged into a binary tree,
nearly optimal assuming equal probability for each case.
The list of cases is rearranged into a binary tree,
nearly optimal assuming equal probability for each case.
The tree is transformed into RTL, eliminating
redundant test conditions at the same time.
The tree is transformed into RTL, eliminating
redundant test conditions at the same time.
If program flow could reach the end of the
decision tree an unconditional jump to the
default code is emitted. */
If program flow could reach the end of the
decision tree an unconditional jump to the
default code is emitted. */
use_cost_table
= (TREE_CODE (orig_type) != ENUMERAL_TYPE
&& estimate_case_costs (case_list));
balance_case_nodes (&case_list, NULL);
emit_case_nodes (index, case_list, default_label, index_type);
emit_jump (default_label);
}
use_cost_table
= (TREE_CODE (orig_type) != ENUMERAL_TYPE
&& estimate_case_costs (case_list));
balance_case_nodes (&case_list, NULL);
emit_case_nodes (index, case_list, default_label, index_type);
emit_jump (default_label);
}
else
{