2011/7/20 Richard Guenther <richard.guent...@gmail.com>:
> On Wed, Jul 20, 2011 at 3:31 PM, Kai Tietz <ktiet...@googlemail.com> wrote:
>> 2011/7/20 Richard Guenther <richard.guent...@gmail.com>:
>>> On Wed, Jul 20, 2011 at 3:05 PM, Kai Tietz <ktiet...@googlemail.com> wrote:
>>>> Hello,
>>>>
>>>> this is the revised version of the partial pre-approved patch for
>>>> preserving
>>>> type-casts from/to boolean-types. It fixes additionally the regression in
>>>> tree-ssa/builtin-expect-5.c testcase, which was caused by
>>>> fold_builtin_expect.
>>>> Additionally there was a regression in gcc.dg/pr28685-1.c, which is fixed
>>>> by
>>>> the change in tree-ssa-forwprop.c's function simplify_bitwise_binary. This
>>>> is just temporary necessary. As soon as we are boolifying comparisons in
>>>> gimplifier, the pattern-matching in tree-ssa-reassoc will match for 2
>>>> branched cases
>>>> again and we can remove the hunk from forward-propagation again.
>>>
>>> Hm, if we can't apply this pieces without regressions we shouldn't. They
>>> can then wait for the boolification patch.
>>>
>>> Can you explain the fold_builtin_expect change? I'm lost in the maze
>>> of inner/inner_arg0/arg0 renaming game. It looks as if the patch only
>>> moves stuff - but that can't possibly be the case. So, what's going on
>>> there?
>>
>> Well, the issue is here that fold_builtin_expect checks here for a
>> comparison. If this comparison was created initially with a
>> boolean-type, the cast to 'long' will be in tree arg0 = (long)
>> CMP-with-boolean-type, as we are preserving here casts from
>> boolean-types (see the fold-const change). So we need to see through
>> this casts to match the compare and call cases. So I moved this "see
>> through" part before first pattern-match and introduced here a
>> helper-variable inner_arg0 to avoid double while-loop. The "inner"
>> variable might get invalid
>> ...
>> if (COMPARISON_CLASS_P (inner)
>> && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST)
>> inner = TREE_OPERAND (inner, 0);
>> ...
>>
>> These are those "prefixed casts" you were asking in the other patch about.
>
> I see. So, if the builtin.c parts bootstrap & test ok then they are ok
> to commit separately.
>
> Thanks,
> Richard.
>
>> Regards,
>> Kai
>>
Hello,
2011-07-20 Kai Tietz <kti...@redhat.com>
* builtins.c (fold_builtin_expect): See through the cast
from truthvalue_type_node to long.
Bootstrapped and regression tested for all languages (including Ada
and Obj-C++) on host x86_64-pc-linux-gnu.
Applied as pre-approved.
Regards,
Kai
Index: gcc-head/gcc/builtins.c
===================================================================
--- gcc-head.orig/gcc/builtins.c
+++ gcc-head/gcc/builtins.c
@@ -6264,13 +6264,22 @@ build_builtin_expect_predicate (location
static tree
fold_builtin_expect (location_t loc, tree arg0, tree arg1)
{
- tree inner, fndecl;
+ tree inner, fndecl, inner_arg0;
enum tree_code code;
+ /* Distribute the expected value over short-circuiting operators.
+ See through the cast from truthvalue_type_node to long. */
+ inner_arg0 = arg0;
+ while (TREE_CODE (inner_arg0) == NOP_EXPR
+ && INTEGRAL_TYPE_P (TREE_TYPE (inner_arg0))
+ && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (inner_arg0, 0))))
+ inner_arg0 = TREE_OPERAND (inner_arg0, 0);
+
/* If this is a builtin_expect within a builtin_expect keep the
inner one. See through a comparison against a constant. It
might have been added to create a thruthvalue. */
- inner = arg0;
+ inner = inner_arg0;
+
if (COMPARISON_CLASS_P (inner)
&& TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST)
inner = TREE_OPERAND (inner, 0);
@@ -6281,14 +6290,7 @@ fold_builtin_expect (location_t loc, tre
&& DECL_FUNCTION_CODE (fndecl) == BUILT_IN_EXPECT)
return arg0;
- /* Distribute the expected value over short-circuiting operators.
- See through the cast from truthvalue_type_node to long. */
- inner = arg0;
- while (TREE_CODE (inner) == NOP_EXPR
- && INTEGRAL_TYPE_P (TREE_TYPE (inner))
- && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (inner, 0))))
- inner = TREE_OPERAND (inner, 0);
-
+ inner = inner_arg0;
code = TREE_CODE (inner);
if (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
{
@@ -6303,13 +6305,13 @@ fold_builtin_expect (location_t loc, tre
}
/* If the argument isn't invariant then there's nothing else we can do. */
- if (!TREE_CONSTANT (arg0))
+ if (!TREE_CONSTANT (inner_arg0))
return NULL_TREE;
/* If we expect that a comparison against the argument will fold to
a constant return the constant. In practice, this means a true
constant or the address of a non-weak symbol. */
- inner = arg0;
+ inner = inner_arg0;
STRIP_NOPS (inner);
if (TREE_CODE (inner) == ADDR_EXPR)
{
2011-07-20 Kai Tietz <kti...@redhat.com>
* fold-const.c (fold_unary_loc): Preserve
non-boolean-typed casts.
* tree-ssa.c (useless_type_conversion_p): Preserve incompatible
casts from/to boolean,
* builtins.c (fold_builtin_expect): See through the cast
from truthvalue_type_node to long.
* tree-ssa-forwprop.c (simplify_bitwise_binary): Add
simplification for CMP bitwise-binary CMP.
