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predict.c (expr_expected_value_1): Assume compare-and-swap builtin boolean return is true.

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* predict.c (expr_expected_value_1): Assume compare-and-swap builtin
        boolean return is true.

From-SVN: r181862
This commit is contained in:
Richard Henderson 2011-11-30 14:19:02 -08:00 • committed by Richard Henderson
parent ed079c4be7
commit c08472eaf6
2 changed files with 36 additions and 11 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2011-11-30 Richard Henderson <rth@redhat.com>
* predict.c (expr_expected_value_1): Assume compare-and-swap builtin
boolean return is true.
2011-11-30 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/51044

42
gcc/predict.c
View file

@ -1190,7 +1190,8 @@ static tree expr_expected_value (tree, bitmap);
/* Helper function for expr_expected_value. */
static tree
expr_expected_value_1 (tree type, tree op0, enum tree_code code, tree op1, bitmap visited)
expr_expected_value_1 (tree type, tree op0, enum tree_code code,
tree op1, bitmap visited)
{
gimple def;
@ -1255,17 +1256,36 @@ expr_expected_value_1 (tree type, tree op0, enum tree_code code, tree op1, bitma
tree decl = gimple_call_fndecl (def);
if (!decl)
return NULL;
if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
&& DECL_FUNCTION_CODE (decl) == BUILT_IN_EXPECT)
{
tree val;
if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
switch (DECL_FUNCTION_CODE (decl))
{
case BUILT_IN_EXPECT:
{
tree val;
if (gimple_call_num_args (def) != 2)
return NULL;
val = gimple_call_arg (def, 0);
if (TREE_CONSTANT (val))
return val;
return gimple_call_arg (def, 1);
}
if (gimple_call_num_args (def) != 2)
return NULL;
val = gimple_call_arg (def, 0);
if (TREE_CONSTANT (val))
return val;
return gimple_call_arg (def, 1);
case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_N:
case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_1:
case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_2:
case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_4:
case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_8:
case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_16:
case BUILT_IN_ATOMIC_COMPARE_EXCHANGE:
case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_N:
case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_1:
case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_2:
case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_4:
case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_8:
case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_16:
/* Assume that any given atomic operation has low contention,
and thus the compare-and-swap operation succeeds. */
return boolean_true_node;
}
}