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fold-const.c (fold_comparision): Remove the "foo++ == CONST" transformation.

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2007-05-02  Andrew Pinski  <andrew_pinski@playstation.sony.com>

        * fold-const.c (fold_comparision): Remove the "foo++ == CONST"
        transformation.

From-SVN: r124353
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Andrew Pinski 2007-05-02 17:47:06 +00:00 committed by Andrew Pinski
parent 5271f9bad5
commit 0e3aa12623
2 changed files with 5 additions and 63 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2007-05-02 Andrew Pinski <andrew_pinski@playstation.sony.com>
* fold-const.c (fold_comparision): Remove the "foo++ == CONST"
transformation.
2007-05-02 Nick Clifton <nickc@redhat.com>
* config/frv/predicates.md (symbolic_operand): Accept CONSTs.

63
gcc/fold-const.c
View File

@ -8649,69 +8649,6 @@ fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
}
}
/* Convert foo++ == CONST into ++foo == CONST + INCR. */
if (TREE_CONSTANT (arg1)
&& (TREE_CODE (arg0) == POSTINCREMENT_EXPR
|| TREE_CODE (arg0) == POSTDECREMENT_EXPR)
/* This optimization is invalid for ordered comparisons
if CONST+INCR overflows or if foo+incr might overflow.
This optimization is invalid for floating point due to rounding.
For pointer types we assume overflow doesn't happen. */
&& (POINTER_TYPE_P (TREE_TYPE (arg0))
|| (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
&& (code == EQ_EXPR || code == NE_EXPR))))
{
tree varop, newconst;
if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
{
newconst = fold_build2 (PLUS_EXPR, TREE_TYPE (arg0),
arg1, TREE_OPERAND (arg0, 1));
varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
TREE_OPERAND (arg0, 0),
TREE_OPERAND (arg0, 1));
}
else
{
newconst = fold_build2 (MINUS_EXPR, TREE_TYPE (arg0),
arg1, TREE_OPERAND (arg0, 1));
varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
TREE_OPERAND (arg0, 0),
TREE_OPERAND (arg0, 1));
}
/* If VAROP is a reference to a bitfield, we must mask
the constant by the width of the field. */
if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
&& DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
&& host_integerp (DECL_SIZE (TREE_OPERAND
(TREE_OPERAND (varop, 0), 1)), 1))
{
tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
tree folded_compare, shift;
/* First check whether the comparison would come out
always the same. If we don't do that we would
change the meaning with the masking. */
folded_compare = fold_build2 (code, type,
TREE_OPERAND (varop, 0), arg1);
if (TREE_CODE (folded_compare) == INTEGER_CST)
return omit_one_operand (type, folded_compare, varop);
shift = build_int_cst (NULL_TREE,
TYPE_PRECISION (TREE_TYPE (varop)) - size);
shift = fold_convert (TREE_TYPE (varop), shift);
newconst = fold_build2 (LSHIFT_EXPR, TREE_TYPE (varop),
newconst, shift);
newconst = fold_build2 (RSHIFT_EXPR, TREE_TYPE (varop),
newconst, shift);
}
return fold_build2 (code, type, varop, newconst);
}
if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
&& (TREE_CODE (arg0) == NOP_EXPR
|| TREE_CODE (arg0) == CONVERT_EXPR))