On Mon, Jul 25, 2011 at 12:08 PM, Kai Tietz <[email protected]> wrote:
> Hello,
>
> this patch removes TRUTH-binary expressions and adjusts some places about
> bitwise-binary-expressions.
>
> ChangeLog gcc
>
> 2011-07-25 Kai Tietz <[email protected]>
>
> * tree-vrp.c (extract_range_from_binary_expr): Remove
> TRUTH-binary cases and add new bitwise cases.
> (extract_range_from_assignment): Likewise.
> (register_edge_assert_for_1): Likewise.
> (register_edge_assert_for): Likewise.
> (simplify_truth_ops_using_ranges): Likewise.
> (simplify_stmt_using_ranges): Likewise.
>
> Bootstrapped and regression tested for all standard languages
> (including Ada and Obj-C++) on
> host x86_64-pc-linux-gnu. Ok for apply?
>
>
> Regards,
> Kai
>
> Index: gcc-head/gcc/tree-vrp.c
> ===================================================================
> --- gcc-head.orig/gcc/tree-vrp.c
> +++ gcc-head/gcc/tree-vrp.c
> @@ -2171,9 +2171,7 @@ extract_range_from_binary_expr (value_ra
> && code != MIN_EXPR
> && 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 +2226,7 @@ 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 +2248,12 @@ 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)
> + if (code == BIT_IOR_EXPR)
> + {
> + set_value_range_to_varying (vr);
> + return;
> + }
> + 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 +2298,9 @@ 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)
> + 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
> @@ -2675,9 +2629,10 @@ extract_range_from_binary_expr (value_ra
> else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR)
> {
> bool vr0_int_cst_singleton_p, vr1_int_cst_singleton_p;
> - bool int_cst_range0, int_cst_range1;
> + bool int_cst_range0, int_cst_range1, is_var_range;
> double_int may_be_nonzero0, may_be_nonzero1;
> double_int must_be_nonzero0, must_be_nonzero1;
> + value_range_t *cst_vr, *var_vr;
>
> vr0_int_cst_singleton_p = range_int_cst_singleton_p (&vr0);
> vr1_int_cst_singleton_p = range_int_cst_singleton_p (&vr1);
> @@ -2686,9 +2641,47 @@ extract_range_from_binary_expr (value_ra
> int_cst_range1 = zero_nonzero_bits_from_vr (&vr1, &may_be_nonzero1,
> &must_be_nonzero1);
>
> + cst_vr = (vr0_int_cst_singleton_p ? &vr0 : &vr1);
singleton_val = vr0_int_cst_singleton_p ? vr0.min : vr1.min
avoids writing cst_vr->min / cst_vr->max below when they are the same
anyway, thus making the code reasier to read.
> + var_vr = (vr0_int_cst_singleton_p ? &vr1 : &vr0);
non_singleton_vr = ...
these are easier to understand imho.
> + is_var_range = (vr0_int_cst_singleton_p ? int_cst_range1 :
> int_cst_range0);
> +
> 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 ((vr0_int_cst_singleton_p || vr1_int_cst_singleton_p)
> + && (integer_zerop (cst_vr->max)
> + || integer_all_onesp (cst_vr->max)))
> + {
> + /* If one of the operands is zero, we know that the whole
> + expression evaluates zero. */
> + if (code == BIT_AND_EXPR && integer_zerop (cst_vr->max))
> + min = max = build_int_cst (expr_type, 0);
You can re-use singleton_val.
> + /* 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 && integer_all_onesp (cst_vr->max))
> + min = max = fold_convert (expr_type, cst_vr->min);
For example here you mix ->max and ->min.
I think you do not need the fold_convert calls.
> + /* If one of the operands has all bits set to one, we know
> + that the whole expression evaluates to the other one. */
> + else if (code == BIT_AND_EXPR && integer_all_onesp (cst_vr->max)
> + && is_var_range)
> + {
> + min = fold_convert (expr_type, var_vr->min);
> + max = fold_convert (expr_type, var_vr->max);
Likewise. This is also valid if !is_var_range, so why restrict it to
the is_var_range case (I note that zero_nonzero_bits_from_vr does not
even return true for all integer ranges)?
> + }
> + /* If one of the operands is zero, we know that the whole
> + expression evaluates to the other one. */
> + else if (code == BIT_IOR_EXPR && integer_zerop (cst_vr->max)
> + && is_var_range)
> + {
> + min = fold_convert (expr_type, var_vr->min);
> + max = fold_convert (expr_type, var_vr->max);
Likewise.
> + }
> + else
> + {
> + set_value_range_to_varying (vr);
> + return;
> + }
Re-structuring the ifs to non-nested like
if (code == BIT_AND_EXPR && integer_zerop (singleton_val))
...
else if (code == ...)
doesn't make it necessary to repeat the set-to-varying case. It also
makes sure we apply the remaining case.
The rest of the patch looks good to me.
Thanks,
Richard.
> + }
> else if (!int_cst_range0 && !int_cst_range1)
> {
> set_value_range_to_varying (vr);
> @@ -3300,10 +3293,7 @@ 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),
> @@ -4516,11 +4506,9 @@ 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),
> @@ -4585,8 +4573,8 @@ 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 +4582,7 @@ 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);
> @@ -4604,20 +4591,20 @@ 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))))
> {
> gimple def_stmt = SSA_NAME_DEF_STMT (name);
>
> + /* For BIT_IOR_EXPR only if NAME == 0 both operands have
> + necessarily zero value, or if type-precision is one. */
> if (is_gimple_assign (def_stmt)
> - && (gimple_assign_rhs_code (def_stmt) == TRUTH_OR_EXPR
> - /* 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
> + && (TYPE_PRECISION (TREE_TYPE (name)) == 1
> + || comp_code == EQ_EXPR)))
> {
> tree op0 = gimple_assign_rhs1 (def_stmt);
> tree op1 = gimple_assign_rhs2 (def_stmt);
> @@ -6786,8 +6773,7 @@ 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 != NE_EXPR)
> return false;
>
> if (!integer_zerop (op1)
> @@ -6831,14 +6817,9 @@ 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 +6834,6 @@ 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;
> - break;
> - case TRUTH_XOR_EXPR:
> case NE_EXPR:
> if (integer_zerop (op1))
> {
> @@ -7415,9 +7389,6 @@ simplify_stmt_using_ranges (gimple_stmt_
> 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
> or identity if the RHS is zero or one, and the LHS are known
> to be boolean values. Transform all TRUTH_*_EXPR into
>
