On Fri, Jul 22, 2011 at 10:14 AM, Kai Tietz <ktiet...@googlemail.com> wrote:
> 2011/7/21 Richard Guenther <richard.guent...@gmail.com>:
>> On Thu, Jul 21, 2011 at 3:09 PM, Kai Tietz <ktiet...@googlemail.com> wrote:
>>> Hello,
>>>
>>> this patch changes TRUTH-expression patterns into BIT-expression ones
>>> and adjusts code-flow
>>> for this.
>>>
>>> ChangeLog gcc
>>>
>>> 2011-07-21 Kai Tietz <kti...@redhat.com>
>>>
>>> * tree-vrp.c (extract_range_from_binary_expr): Convert
>>> truth expression to bimary expression,
>>> (extract_range_from_unary_expr): Likewise.
>>> (extract_range_from_assignment): Likewise.
>>> (build_assert_expr_for): Likewise.
>>> (register_edge_assert_for_1): Likewise.
>>> (simplify_truth_ops_using_ranges): Likewise.
>>> (simplify_stmt_using_ranges): Likewise.
>>>
>>> do_dce flag to deside, if BB's statements are scanned
>>> in last to first, or first to last order.
>>>
>>> Bootstrapped and regression tested for all standard languages
>>> (including Ada and Obj-C++) on
>>> host x86_64-pc-linux-gnu. Ok for apply?
>>
>> *sigh*, you didn't address any of my comments.
>>
>> Again ...
>>
>>>
>>> Regards,
>>> Kai
>>>
>>> Index: gcc-head/gcc/tree-vrp.c
>>> ===================================================================
>>> --- gcc-head.orig/gcc/tree-vrp.c
>>> +++ gcc-head/gcc/tree-vrp.c
>>> @@ -2172,8 +2172,6 @@ extract_range_from_binary_expr (value_ra
>>> && code != MAX_EXPR
>>> && code != BIT_AND_EXPR
>>> - && code != BIT_IOR_EXPR
>>> - && code != TRUTH_AND_EXPR
>>> - && code != TRUTH_OR_EXPR)
>>> + && code != BIT_IOR_EXPR)
>>> {
>>> /* We can still do constant propagation here. */
>>> tree const_op0 = op_with_constant_singleton_value_range (op0);
>>> @@ -2228,8 +2227,7 @@ extract_range_from_binary_expr (value_ra
>>> divisions. TODO, we may be able to derive anti-ranges in
>>> some cases. */
>>> if (code != BIT_AND_EXPR
>>> - && code != TRUTH_AND_EXPR
>>> - && code != TRUTH_OR_EXPR
>>> + && code != BIT_IOR_EXPR
>>> && code != TRUNC_DIV_EXPR
>>> && code != FLOOR_DIV_EXPR
>>> && code != CEIL_DIV_EXPR
>>> @@ -2251,7 +2249,10 @@ extract_range_from_binary_expr (value_ra
>>> || POINTER_TYPE_P (TREE_TYPE (op0))
>>> || POINTER_TYPE_P (TREE_TYPE (op1)))
>>> {
>>> - if (code == MIN_EXPR || code == MAX_EXPR)
>>> + /* We need to preserve here bitwise-or for pointer types. */
>>
>> Preserve? I asked how you end up seeing BIT_IOR_EXPR here, you
>> didn't answer that yet.
>
> Well, we see that here in case of truth. So we need to allow it at
> top, and indeed I noticed that we have IOR patterns on address-typed
> expressions, so I added here default handling for it, as otherwise we
> would run into the gcc_unreachable for it.
We would run into it right now without this patch and we don't.
>>> + if (code == BIT_IOR_EXPR)
>>> + set_value_range_to_varying (vr);
>>> + else if (code == MIN_EXPR || code == MAX_EXPR)
>>> {
>>> /* For MIN/MAX expressions with pointers, we only care about
>>> nullness, if both are non null, then the result is nonnull.
>>> @@ -2296,57 +2297,8 @@ extract_range_from_binary_expr (value_ra
>>>
>>> /* For integer ranges, apply the operation to each end of the
>>> range and see what we end up with. */
>>> - if (code == TRUTH_AND_EXPR
>>> - || code == TRUTH_OR_EXPR)
>>> - {
>>> - /* If one of the operands is zero, we know that the whole
>>> - expression evaluates zero. */
>>> - if (code == TRUTH_AND_EXPR
>>> - && ((vr0.type == VR_RANGE
>>> - && integer_zerop (vr0.min)
>>> - && integer_zerop (vr0.max))
>>> - || (vr1.type == VR_RANGE
>>> - && integer_zerop (vr1.min)
>>> - && integer_zerop (vr1.max))))
>>> - {
>>> - type = VR_RANGE;
>>> - min = max = build_int_cst (expr_type, 0);
>>> - }
>>> - /* If one of the operands is one, we know that the whole
>>> - expression evaluates one. */
>>> - else if (code == TRUTH_OR_EXPR
>>> - && ((vr0.type == VR_RANGE
>>> - && integer_onep (vr0.min)
>>> - && integer_onep (vr0.max))
>>> - || (vr1.type == VR_RANGE
>>> - && integer_onep (vr1.min)
>>> - && integer_onep (vr1.max))))
>>> - {
>>> - type = VR_RANGE;
>>> - min = max = build_int_cst (expr_type, 1);
>>> - }
>>> - else if (vr0.type != VR_VARYING
>>> - && vr1.type != VR_VARYING
>>> - && vr0.type == vr1.type
>>> - && !symbolic_range_p (&vr0)
>>> - && !overflow_infinity_range_p (&vr0)
>>> - && !symbolic_range_p (&vr1)
>>> - && !overflow_infinity_range_p (&vr1))
>>> - {
>>> - /* Boolean expressions cannot be folded with int_const_binop. */
>>> - min = fold_binary (code, expr_type, vr0.min, vr1.min);
>>> - max = fold_binary (code, expr_type, vr0.max, vr1.max);
>>> - }
>>> - else
>>> - {
>>> - /* The result of a TRUTH_*_EXPR is always true or false. */
>>> - set_value_range_to_truthvalue (vr, expr_type);
>>> - return;
>>> - }
>>> - }
>>> - else if (code == PLUS_EXPR
>>> - || code == MIN_EXPR
>>> - || code == MAX_EXPR)
>>
>> The above hunk looks good, removing dead code, but ...
>>
>>> + if (code == PLUS_EXPR || code == MIN_EXPR
>>> + || code == MAX_EXPR)
>>> {
>>> /* If we have a PLUS_EXPR with two VR_ANTI_RANGEs, drop to
>>> VR_VARYING. It would take more effort to compute a precise
>>> @@ -2679,73 +2631,127 @@ extract_range_from_binary_expr (value_ra
>>> double_int may_be_nonzero0, may_be_nonzero1;
>>> double_int must_be_nonzero0, must_be_nonzero1;
>>>
>>> - vr0_int_cst_singleton_p = range_int_cst_singleton_p (&vr0);
>>> - vr1_int_cst_singleton_p = range_int_cst_singleton_p (&vr1);
>>> - int_cst_range0 = zero_nonzero_bits_from_vr (&vr0, &may_be_nonzero0,
>>> - &must_be_nonzero0);
>>> - int_cst_range1 = zero_nonzero_bits_from_vr (&vr1, &may_be_nonzero1,
>>> - &must_be_nonzero1);
>>> -
>>> - type = VR_RANGE;
>>> - if (vr0_int_cst_singleton_p && vr1_int_cst_singleton_p)
>>> - min = max = int_const_binop (code, vr0.max, vr1.max);
>>> - else if (!int_cst_range0 && !int_cst_range1)
>>> + /* If one of the operands is zero, we know that the whole
>>> + expression evaluates zero. */
>>
>> ... starting here it get's odd. You are 1:1 replacing the code here.
>> Don't do that.
>>
>> Instead do nothing here in this patch.
>>
>>> + if (code == BIT_AND_EXPR
>>> + && ((vr0.type == VR_RANGE
>>> + && integer_zerop (vr0.min)
>>> + && integer_zerop (vr0.max))
>>> + || (vr1.type == VR_RANGE
>>> + && integer_zerop (vr1.min)
>>> + && integer_zerop (vr1.max))))
>>> + {
>>> + type = VR_RANGE;
>>> + min = max = build_int_cst (expr_type, 0);
>>> + }
>>> + /* If one of the operands has all bits set to one, we know
>>> + that the whole expression evaluates to this one. */
>>> + else if (code == BIT_IOR_EXPR
>>> + && (vr0.type == VR_RANGE
>>> + && integer_all_onesp (vr0.min)
>>> + && integer_all_onesp (vr0.max)))
>>> + {
>>> + type = VR_RANGE;
>>> + min = max = fold_convert (expr_type, vr0.min);
>>> + }
>>> + else if (code == BIT_IOR_EXPR
>>> + && (vr1.type == VR_RANGE
>>> + && integer_all_onesp (vr1.min)
>>> + && integer_all_onesp (vr1.max)))
>>> {
>>> - set_value_range_to_varying (vr);
>>> - return;
>>> + type = VR_RANGE;
>>> + min = max = fold_convert (expr_type, vr1.min);
>>> }
>>> - else if (code == BIT_AND_EXPR)
>>> + else if (TYPE_PRECISION (TREE_TYPE (op1)) == 1)
>>> {
>>> - min = double_int_to_tree (expr_type,
>>> - double_int_and (must_be_nonzero0,
>>> - must_be_nonzero1));
>>> - max = double_int_to_tree (expr_type,
>>> - double_int_and (may_be_nonzero0,
>>> - may_be_nonzero1));
>>> - if (TREE_OVERFLOW (min) || tree_int_cst_sgn (min) < 0)
>>> - min = NULL_TREE;
>>> - if (TREE_OVERFLOW (max) || tree_int_cst_sgn (max) < 0)
>>> - max = NULL_TREE;
>>> - if (int_cst_range0 && tree_int_cst_sgn (vr0.min) >= 0)
>>> - {
>>> - if (min == NULL_TREE)
>>> - min = build_int_cst (expr_type, 0);
>>> - if (max == NULL_TREE || tree_int_cst_lt (vr0.max, max))
>>> - max = vr0.max;
>>> + if (vr0.type != VR_VARYING
>>> + && vr1.type != VR_VARYING
>>> + && vr0.type == vr1.type
>>> + && !symbolic_range_p (&vr0)
>>> + && !overflow_infinity_range_p (&vr0)
>>> + && !symbolic_range_p (&vr1)
>>> + && !overflow_infinity_range_p (&vr1))
>>> + {
>>> + /* Boolean expressions cannot be folded with int_const_binop.
>>> */
>>> + min = fold_binary (code, expr_type, vr0.min, vr1.min);
>>> + max = fold_binary (code, expr_type, vr0.max, vr1.max);
>>> + }
>
> Right I kept this logic due the general code seem to have issues with
> const_binop and Boolean expressions. If you are sure this comment is
> wrong, we might be able to remove here the complete hunks before and
> just use old code for boolean-case, too.
I'm sure this comment is bogus. As with the above, we'd run into the
bug right now, so just remove the TRUTH_* cases.
>>> + else
>>> + {
>>> + set_value_range_to_varying (vr);
>>> + return;
>>> }
>>> - if (int_cst_range1 && tree_int_cst_sgn (vr1.min) >= 0)
>>> + }
>>> + else
>>> + {
>>> + vr0_int_cst_singleton_p = range_int_cst_singleton_p (&vr0);
>>> + vr1_int_cst_singleton_p = range_int_cst_singleton_p (&vr1);
>>> + int_cst_range0 = zero_nonzero_bits_from_vr (&vr0,
>>> &may_be_nonzero0,
>>> + &must_be_nonzero0);
>>> + int_cst_range1 = zero_nonzero_bits_from_vr (&vr1,
>>> &may_be_nonzero1,
>>> + &must_be_nonzero1);
>>> +
>>> + type = VR_RANGE;
>>> + if (vr0_int_cst_singleton_p && vr1_int_cst_singleton_p)
>>> + min = max = int_const_binop (code, vr0.max, vr1.max);
>>> + else if (!int_cst_range0 && !int_cst_range1)
>>> {
>>> - if (min == NULL_TREE)
>>> - min = build_int_cst (expr_type, 0);
>>> - if (max == NULL_TREE || tree_int_cst_lt (vr1.max, max))
>>> - max = vr1.max;
>>> + set_value_range_to_varying (vr);
>>> + return;
>>> + }
>>> + else if (code == BIT_AND_EXPR)
>>> + {
>>> + min = double_int_to_tree (expr_type,
>>> + double_int_and (must_be_nonzero0,
>>> + must_be_nonzero1));
>>> + max = double_int_to_tree (expr_type,
>>> + double_int_and (may_be_nonzero0,
>>> + may_be_nonzero1));
>>> + if (TREE_OVERFLOW (min) || tree_int_cst_sgn (min) < 0)
>>> + min = NULL_TREE;
>>> + if (TREE_OVERFLOW (max) || tree_int_cst_sgn (max) < 0)
>>> + max = NULL_TREE;
>>> + if (int_cst_range0 && tree_int_cst_sgn (vr0.min) >= 0)
>>> + {
>>> + if (min == NULL_TREE)
>>> + min = build_int_cst (expr_type, 0);
>>> + if (max == NULL_TREE || tree_int_cst_lt (vr0.max, max))
>>> + max = vr0.max;
>>> + }
>>> + if (int_cst_range1 && tree_int_cst_sgn (vr1.min) >= 0)
>>> + {
>>> + if (min == NULL_TREE)
>>> + min = build_int_cst (expr_type, 0);
>>> + if (max == NULL_TREE || tree_int_cst_lt (vr1.max, max))
>>> + max = vr1.max;
>>> + }
>>> + }
>>> + else if (!int_cst_range0
>>> + || !int_cst_range1
>>> + || tree_int_cst_sgn (vr0.min) < 0
>>> + || tree_int_cst_sgn (vr1.min) < 0)
>>> + {
>>> + set_value_range_to_varying (vr);
>>> + return;
>>> }
>>> - }
>>> - else if (!int_cst_range0
>>> - || !int_cst_range1
>>> - || tree_int_cst_sgn (vr0.min) < 0
>>> - || tree_int_cst_sgn (vr1.min) < 0)
>>> - {
>>> - set_value_range_to_varying (vr);
>>> - return;
>>> - }
>>> - else
>>> - {
>>> - min = double_int_to_tree (expr_type,
>>> - double_int_ior (must_be_nonzero0,
>>> - must_be_nonzero1));
>>> - max = double_int_to_tree (expr_type,
>>> - double_int_ior (may_be_nonzero0,
>>> - may_be_nonzero1));
>>> - if (TREE_OVERFLOW (min) || tree_int_cst_sgn (min) < 0)
>>> - min = vr0.min;
>>> else
>>> - min = vrp_int_const_binop (MAX_EXPR, min, vr0.min);
>>> - if (TREE_OVERFLOW (max) || tree_int_cst_sgn (max) < 0)
>>> - max = NULL_TREE;
>>> - min = vrp_int_const_binop (MAX_EXPR, min, vr1.min);
>>> + {
>>> + min = double_int_to_tree (expr_type,
>>> + double_int_ior (must_be_nonzero0,
>>> + must_be_nonzero1));
>>> + max = double_int_to_tree (expr_type,
>>> + double_int_ior (may_be_nonzero0,
>>> + may_be_nonzero1));
>>> + if (TREE_OVERFLOW (min) || tree_int_cst_sgn (min) < 0)
>>> + min = vr0.min;
>>> + else
>>> + min = vrp_int_const_binop (MAX_EXPR, min, vr0.min);
>>> + if (TREE_OVERFLOW (max) || tree_int_cst_sgn (max) < 0)
>>> + max = NULL_TREE;
>>> + min = vrp_int_const_binop (MAX_EXPR, min, vr1.min);
>>> + }
>>> }
>>> - }
>>> + }
>>> else
>>> gcc_unreachable ();
>>>
>>> @@ -2806,7 +2812,7 @@ extract_range_from_unary_expr (value_ran
>>> cannot easily determine a resulting range. */
>>> if (code == FIX_TRUNC_EXPR
>>> || code == FLOAT_EXPR
>>> - || code == BIT_NOT_EXPR
>>> + || (code == BIT_NOT_EXPR && TYPE_PRECISION (type) != 1)
>>
>> Likewise - this looks unrelated to TRUTH_* code removal. And I asked you
>> to instead properly handle BOT_NOT_EXPR completely (in a separate
>> patch).
>
> Well, I don't think it is unrealted for truth to binary transition,
> but you are right that this check
> is for now dead code (see later comment why it isn't, and why we will
> see here BIT_XOR_EXPR see second part). To disallow here BIT_XOR_EXPR
> might not be a big deal, but we might loose here some
> folding-opportunites in vrp, which gets then done by later-passes
> anyway.
>
>>> || code == CONJ_EXPR)
>>> {
>>> /* We can still do constant propagation here. */
>>> @@ -3300,10 +3306,7 @@ extract_range_from_assignment (value_ran
>>> extract_range_from_assert (vr, gimple_assign_rhs1 (stmt));
>>> else if (code == SSA_NAME)
>>> extract_range_from_ssa_name (vr, gimple_assign_rhs1 (stmt));
>>> - else if (TREE_CODE_CLASS (code) == tcc_binary
>>> - || code == TRUTH_AND_EXPR
>>> - || code == TRUTH_OR_EXPR
>>> - || code == TRUTH_XOR_EXPR)
>>> + else if (TREE_CODE_CLASS (code) == tcc_binary)
>>> extract_range_from_binary_expr (vr, gimple_assign_rhs_code (stmt),
>>> gimple_expr_type (stmt),
>>> gimple_assign_rhs1 (stmt),
>>> @@ -3973,9 +3976,10 @@ build_assert_expr_for (tree cond, tree v
>>> tree a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond);
>>> assertion = gimple_build_assign (n, a);
>>> }
>>> - else if (TREE_CODE (cond) == TRUTH_NOT_EXPR)
>>> + else if (TREE_CODE (cond) == BIT_NOT_EXPR
>>> + && TYPE_PRECISION (TREE_TYPE (cond)) == 1)
>>> {
>>> - /* Given !V, build the assignment N = false. */
>>> + /* Given ~V, build the assignment N = false. */
>>> tree op0 = TREE_OPERAND (cond, 0);
>>> gcc_assert (op0 == v);
>>> assertion = gimple_build_assign (n, boolean_false_node);
>>
>> See my previous comment. This is dead code, if you want to do a cleanup
>> inline it into its sole caller.
>>
>>> @@ -4516,11 +4520,9 @@ register_edge_assert_for_1 (tree op, enu
>>> invert);
>>> }
>>> else if ((code == NE_EXPR
>>> - && (gimple_assign_rhs_code (op_def) == TRUTH_AND_EXPR
>>> - || gimple_assign_rhs_code (op_def) == BIT_AND_EXPR))
>>> + && gimple_assign_rhs_code (op_def) == BIT_AND_EXPR)
>>> || (code == EQ_EXPR
>>> - && (gimple_assign_rhs_code (op_def) == TRUTH_OR_EXPR
>>> - || gimple_assign_rhs_code (op_def) == BIT_IOR_EXPR)))
>>> + && gimple_assign_rhs_code (op_def) == BIT_IOR_EXPR))
>>> {
>>> /* Recurse on each operand. */
>>> retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def),
>>> @@ -4528,7 +4530,8 @@ register_edge_assert_for_1 (tree op, enu
>>> retval |= register_edge_assert_for_1 (gimple_assign_rhs2 (op_def),
>>> code, e, bsi);
>>> }
>>> - else if (gimple_assign_rhs_code (op_def) == TRUTH_NOT_EXPR)
>>> + else if (gimple_assign_rhs_code (op_def) == BIT_NOT_EXPR
>>> + && TYPE_PRECISION (TREE_TYPE (op)) == 1)
>>> {
>>> /* Recurse, flipping CODE. */
>>> code = invert_tree_comparison (code, false);
>>> @@ -4585,8 +4588,8 @@ register_edge_assert_for (tree name, edg
>>> the value zero or one, then we may be able to assert values
>>> for SSA_NAMEs which flow into COND. */
>>>
>>> - /* In the case of NAME == 1 or NAME != 0, for TRUTH_AND_EXPR defining
>>> - statement of NAME we can assert both operands of the TRUTH_AND_EXPR
>>> + /* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining
>>> + statement of NAME we can assert both operands of the BIT_AND_EXPR
>>> have nonzero value. */
>>> if (((comp_code == EQ_EXPR && integer_onep (val))
>>> || (comp_code == NE_EXPR && integer_zerop (val))))
>>> @@ -4594,8 +4597,7 @@ register_edge_assert_for (tree name, edg
>>> gimple def_stmt = SSA_NAME_DEF_STMT (name);
>>>
>>> if (is_gimple_assign (def_stmt)
>>> - && (gimple_assign_rhs_code (def_stmt) == TRUTH_AND_EXPR
>>> - || gimple_assign_rhs_code (def_stmt) == BIT_AND_EXPR))
>>> + && gimple_assign_rhs_code (def_stmt) == BIT_AND_EXPR)
>>> {
>>> tree op0 = gimple_assign_rhs1 (def_stmt);
>>> tree op1 = gimple_assign_rhs2 (def_stmt);
>>> @@ -4604,8 +4606,8 @@ register_edge_assert_for (tree name, edg
>>> }
>>> }
>>>
>>> - /* In the case of NAME == 0 or NAME != 1, for TRUTH_OR_EXPR defining
>>> - statement of NAME we can assert both operands of the TRUTH_OR_EXPR
>>> + /* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining
>>> + statement of NAME we can assert both operands of the BIT_IOR_EXPR
>>> have zero value. */
>>> if (((comp_code == EQ_EXPR && integer_zerop (val))
>>> || (comp_code == NE_EXPR && integer_onep (val))))
>>> @@ -4613,11 +4615,12 @@ register_edge_assert_for (tree name, edg
>>> gimple def_stmt = SSA_NAME_DEF_STMT (name);
>>>
>>> if (is_gimple_assign (def_stmt)
>>> - && (gimple_assign_rhs_code (def_stmt) == TRUTH_OR_EXPR
>>> + && ((gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR
>>> + && TYPE_PRECISION (TREE_TYPE (name)) == 1)
>>> /* For BIT_IOR_EXPR only if NAME == 0 both operands have
>>> necessarily zero value. */
>>> || (comp_code == EQ_EXPR
>>> - && (gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR))))
>>> + && gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR)))
>>
>> Again you ignored my previous comments - why do I even look at the
>> patches? This code simplifies if you CSE the BIT_IOR_EXPR test
>> and move and adjust the comment.
>>
>>> {
>>> tree op0 = gimple_assign_rhs1 (def_stmt);
>>> tree op1 = gimple_assign_rhs2 (def_stmt);
>>> @@ -6772,7 +6775,7 @@ simplify_truth_ops_using_ranges (gimple_
>>> return false;
>>> }
>>>
>>> - if (rhs_code == TRUTH_NOT_EXPR)
>>> + if (rhs_code == BIT_NOT_EXPR && TYPE_PRECISION (TREE_TYPE (op0)) == 1)
>>> {
>>
>> We never want to transform BIT_NOT_EXPR to BIT_XOR_EXPR, so
>> please instead remove this code and do not call
>> simplify_thuth_ops_using_ranges for BIT_NOT_EXPRs.
>>
>>> rhs_code = NE_EXPR;
>>> op1 = build_int_cst (TREE_TYPE (op0), 1);
>>> @@ -6787,7 +6790,7 @@ simplify_truth_ops_using_ranges (gimple_
>>> /* Exclude anything that should have been already folded. */
>>> if (rhs_code != EQ_EXPR
>>> && rhs_code != NE_EXPR
>>> - && rhs_code != TRUTH_XOR_EXPR)
>>> + && rhs_code != BIT_XOR_EXPR)
>>
>> Sure not, we are not calling this function with BIT_XOR_EXPR either.
>>
>>> return false;
>>>
>>> if (!integer_zerop (op1)
>>> @@ -6799,6 +6802,8 @@ simplify_truth_ops_using_ranges (gimple_
>>> if (rhs_code == EQ_EXPR)
>>> {
>>> rhs_code = NE_EXPR;
>>> + /* We can use here TRUTH_NOT_EXPR for doing logical-not
>>> + on constant. */
>>> op1 = fold_unary (TRUTH_NOT_EXPR, TREE_TYPE (op1), op1);
>>> }
>>> }
>>> @@ -6831,14 +6836,9 @@ simplify_truth_ops_using_ranges (gimple_
>>> else
>>> location = gimple_location (stmt);
>>>
>>> - if (rhs_code == TRUTH_AND_EXPR || rhs_code == TRUTH_OR_EXPR)
>>> - warning_at (location, OPT_Wstrict_overflow,
>>> - _("assuming signed overflow does not occur when "
>>> - "simplifying && or || to & or |"));
>>> - else
>>> - warning_at (location, OPT_Wstrict_overflow,
>>> - _("assuming signed overflow does not occur when "
>>> - "simplifying ==, != or ! to identity or ^"));
>>> + warning_at (location, OPT_Wstrict_overflow,
>>> + _("assuming signed overflow does not occur when "
>>> + "simplifying ==, != or ! to identity or ^"));
>>> }
>>>
>>> need_conversion =
>>> @@ -6853,13 +6853,10 @@ simplify_truth_ops_using_ranges (gimple_
>>>
>>> switch (rhs_code)
>>> {
>>> - case TRUTH_AND_EXPR:
>>> - rhs_code = BIT_AND_EXPR;
>>> - break;
>>> - case TRUTH_OR_EXPR:
>>> - rhs_code = BIT_IOR_EXPR;
>>> + case BIT_AND_EXPR:
>>> + case BIT_IOR_EXPR:
>>> break;
>>> - case TRUTH_XOR_EXPR:
>>> + case BIT_XOR_EXPR:
>>
>> We do not call this function for BIT_*_EXPR.
>
> We have to, and we do.
We don't. And we won't have to.
> I agree that for now this code here does not
> much for BIT_IOR/BIT_AND. But with doing result sinking into
> type-cast, it does pretty much here. Please see second patch about
> why this code about BIT_*_EXPR is all but dead.
The second patch puts an unrelated simplification into this function.
> And in light of this even BIT_NOT_EXPR is all but dead-code (and
> should be transformed to XOR), so that we are able to handle cases
> like:
>
> int x, D3;
> _Bool D1, D2;
>
> D1 = (bool) x;
> D2 = ~x;
> D3 = (int) D2
>
> and transform them to 'D3 = x ^ 1'
No, because that would be a wrong transformation.
>>> case NE_EXPR:
>>> if (integer_zerop (op1))
>>> {
>>> @@ -7412,16 +7409,15 @@ simplify_stmt_using_ranges (gimple_stmt_
>>>
>>> switch (rhs_code)
>>> {
>>> + case BIT_NOT_EXPR:
>>> + if (TYPE_PRECISION (TREE_TYPE (rhs1)) != 1)
>>> + break;
>>> + /* Fall through. */
>>
>> See above.
>
> See comment above.
>
>>> case EQ_EXPR:
>>> case NE_EXPR:
>>> - case TRUTH_NOT_EXPR:
>>> - case TRUTH_AND_EXPR:
>>> - case TRUTH_OR_EXPR:
>>> - case TRUTH_XOR_EXPR:
>>> - /* Transform EQ_EXPR, NE_EXPR, TRUTH_NOT_EXPR into BIT_XOR_EXPR
>>> + /* Transform EQ_EXPR, NE_EXPR, BIT_NOT_EXPR into BIT_XOR_EXPR
>>> or identity if the RHS is zero or one, and the LHS are known
>>> - to be boolean values. Transform all TRUTH_*_EXPR into
>>> - BIT_*_EXPR if both arguments are known to be boolean values.
>>> */
>>> + to be boolean values. */
>>> if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
>>> return simplify_truth_ops_using_ranges (gsi, stmt);
>>> break;
>>> @@ -7449,7 +7445,11 @@ simplify_stmt_using_ranges (gimple_stmt_
>>> if all the bits being cleared are already cleared or
>>> all the bits being set are already set. */
>>> if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
>>> - return simplify_bit_ops_using_ranges (gsi, stmt);
>>> + {
>>> + if (simplify_truth_ops_using_ranges (gsi, stmt))
>>> + return true;
>>> + return simplify_bit_ops_using_ranges (gsi, stmt);
>>
>> Stale hunk I suppose.
>
> IMHO not stale. In fact the jumping point about handling here
> bitwise-binary boolean typed expressions. And for second patch an
> essential thing.
It becomes stale if you follow my earlier comments.
Richard.
>> Richard.
>>
>>> + }
>>> break;
>>>
>>> CASE_CONVERT:
>>>
>
> Regards,
> Kai
>
