2011/7/12 Richard Guenther <richard.guent...@gmail.com>:
> On Mon, Jul 11, 2011 at 5:37 PM, Kai Tietz <ktiet...@googlemail.com> wrote:
>> 2011/7/8 Richard Guenther <richard.guent...@gmail.com>:
>>> On Fri, Jul 8, 2011 at 1:32 PM, Kai Tietz <ktiet...@googlemail.com> wrote:
>>>> 2011/7/8 Richard Guenther <richard.guent...@gmail.com>:
>>>>> On Thu, Jul 7, 2011 at 6:07 PM, Kai Tietz <ktiet...@googlemail.com> wrote:
>>>>>> Hello,
>>>>>>
>>>>>> This patch - second of series - adds boolification of comparisions in
>>>>>> gimplifier. For this
>>>>>> casts from/to boolean are marked as not-useless. And in fold_unary_loc
>>>>>> casts to non-boolean integral types are preserved.
>>>>>> The hunk in tree-ssa-forwprop.c in combine_cond-expr_cond is not strictly
>>>>>> necessary - as long as fold-const handles 1-bit precision
>>>>>> bitwise-expression
>>>>>> with truth-logic - but it has shown to short-cut some expensier folding.
>>>>>> So
>>>>>> I kept it within this patch.
>>>>>
>>>>> Please split it out. Also ...
>>>>>
>>>>>>
>>>>>> The adjusted testcase gcc.dg/uninit-15.c indicates that due
>>>>>> optimization we loose
>>>>>> in this case variables declaration. But this might be to be expected.
>>>>>>
>>>>>> In vectorization we have a regression in gcc.dg/vect/vect-cond-3.c
>>>>>> test-case. It's caused
>>>>>> by always having boolean-type on conditions. So vectorizer sees
>>>>>> different types, which
>>>>>> aren't handled by vectorizer right now. Maybe this issue could be
>>>>>> special-cased for
>>>>>> boolean-types in tree-vect-loop, by making operand for used condition
>>>>>> equal to vector-type.
>>>>>> But this is a subject for a different patch and not addressed by this
>>>>>> series.
>>>>>>
>>>>>> There is a regressions in tree-ssa/vrp47.c, and the fix is addressed
>>>>>> by the 3rd patch of this
>>>>>> series.
>>>>>>
>>>>>> Bootstrapped and regression tested for all standard-languages (plus
>>>>>> Ada and Obj-C++) on host x86_64-pc-linux-gnu.
>>>>>>
>>>>>> Ok for apply?
>>>>>>
>>>>>> Regards,
>>>>>> Kai
>>>>>>
>>>>>>
>>>>>> ChangeLog
>>>>>>
>>>>>> 2011-07-07 Kai Tietz <kti...@redhat.com>
>>>>>>
>>>>>> * fold-const.c (fold_unary_loc): Preserve
>>>>>> non-boolean-typed casts.
>>>>>> * gimplify.c (gimple_boolify): Handle boolification
>>>>>> of comparisons.
>>>>>> (gimplify_expr): Boolifiy non aggregate-typed
>>>>>> comparisons.
>>>>>> * tree-cfg.c (verify_gimple_comparison): Check result
>>>>>> type of comparison expression.
>>>>>> * tree-ssa.c (useless_type_conversion_p): Preserve incompatible
>>>>>> casts from/to boolean,
>>>>>> * tree-ssa-forwprop.c (combine_cond_expr_cond): Add simplification
>>>>>> support for one-bit-precision typed X for cases X != 0 and X == 0.
>>>>>> (forward_propagate_comparison): Adjust test of condition
>>>>>> result.
>>>>>>
>>>>>>
>>>>>> * gcc.dg/tree-ssa/builtin-expect-5.c: Adjusted.
>>>>>> * gcc.dg/tree-ssa/pr21031.c: Likewise.
>>>>>> * gcc.dg/tree-ssa/pr30978.c: Likewise.
>>>>>> * gcc.dg/tree-ssa/ssa-fre-6.c: Likewise.
>>>>>> * gcc.dg/binop-xor1.c: Mark it as expected fail.
>>>>>> * gcc.dg/binop-xor3.c: Likewise.
>>>>>> * gcc.dg/uninit-15.c: Adjust reported message.
>>>>>>
>>>>>> Index: gcc-head/gcc/fold-const.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/fold-const.c
>>>>>> +++ gcc-head/gcc/fold-const.c
>>>>>> @@ -7665,11 +7665,11 @@ fold_unary_loc (location_t loc, enum tre
>>>>>> non-integral type.
>>>>>> Do not fold the result as that would not simplify further,
>>>>>> also
>>>>>> folding again results in recursions. */
>>>>>> - if (INTEGRAL_TYPE_P (type))
>>>>>> + if (TREE_CODE (type) == BOOLEAN_TYPE)
>>>>>> return build2_loc (loc, TREE_CODE (op0), type,
>>>>>> TREE_OPERAND (op0, 0),
>>>>>> TREE_OPERAND (op0, 1));
>>>>>> - else
>>>>>> + else if (!INTEGRAL_TYPE_P (type))
>>>>>> return build3_loc (loc, COND_EXPR, type, op0,
>>>>>> fold_convert (type, boolean_true_node),
>>>>>> fold_convert (type, boolean_false_node));
>>>>>> Index: gcc-head/gcc/gimplify.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/gimplify.c
>>>>>> +++ gcc-head/gcc/gimplify.c
>>>>>> @@ -2842,18 +2842,23 @@ gimple_boolify (tree expr)
>>>>>>
>>>>>> case TRUTH_NOT_EXPR:
>>>>>> TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
>>>>>> - /* FALLTHRU */
>>>>>>
>>>>>> - case EQ_EXPR: case NE_EXPR:
>>>>>> - case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
>>>>>> /* These expressions always produce boolean results. */
>>>>>> - TREE_TYPE (expr) = boolean_type_node;
>>>>>> + if (TREE_CODE (type) != BOOLEAN_TYPE)
>>>>>> + TREE_TYPE (expr) = boolean_type_node;
>>>>>> return expr;
>>>>>>
>>>>>> default:
>>>>>> + if (COMPARISON_CLASS_P (expr))
>>>>>> + {
>>>>>> + /* There expressions always prduce boolean results. */
>>>>>> + if (TREE_CODE (type) != BOOLEAN_TYPE)
>>>>>> + TREE_TYPE (expr) = boolean_type_node;
>>>>>> + return expr;
>>>>>> + }
>>>>>> /* Other expressions that get here must have boolean values, but
>>>>>> might need to be converted to the appropriate mode. */
>>>>>> - if (type == boolean_type_node)
>>>>>> + if (TREE_CODE (type) == BOOLEAN_TYPE)
>>>>>> return expr;
>>>>>> return fold_convert_loc (loc, boolean_type_node, expr);
>>>>>> }
>>>>>> @@ -6763,7 +6768,7 @@ gimplify_expr (tree *expr_p, gimple_seq
>>>>>> tree org_type = TREE_TYPE (*expr_p);
>>>>>>
>>>>>> *expr_p = gimple_boolify (*expr_p);
>>>>>> - if (org_type != boolean_type_node)
>>>>>> + if (!useless_type_conversion_p (org_type, TREE_TYPE
>>>>>> (*expr_p)))
>>>>>> {
>>>>>> *expr_p = fold_convert (org_type, *expr_p);
>>>>>
>>>>> Use fold_convert_loc with saved_location
>>>>
>>>> Oh, good catch. Yes, I will adjust that.
>>>>
>>>>>> ret = GS_OK;
>>>>>> @@ -7208,7 +7213,7 @@ gimplify_expr (tree *expr_p, gimple_seq
>>>>>> fold_truth_not_expr) happily uses operand type and doesn't
>>>>>> automatically uses boolean_type as result, we need to keep
>>>>>> orignal type. */
>>>>>> - if (org_type != boolean_type_node)
>>>>>> + if (!useless_type_conversion_p (org_type, TREE_TYPE
>>>>>> (*expr_p)))
>>>>>> {
>>>>>> *expr_p = fold_convert (org_type, *expr_p);
>>>>>
>>>>> Likewise. Maybe this fixes the diagnostic regression.
>>>>>
>>>>>> ret = GS_OK;
>>>>>> @@ -7288,7 +7293,19 @@ gimplify_expr (tree *expr_p, gimple_seq
>>>>>> tree type = TREE_TYPE (TREE_OPERAND (*expr_p, 1));
>>>>>>
>>>>>> if (!AGGREGATE_TYPE_P (type))
>>>>>> - goto expr_2;
>>>>>> + {
>>>>>> + tree org_type = TREE_TYPE (*expr_p);
>>>>>> + *expr_p = gimple_boolify (*expr_p);
>>>>>> + if (!useless_type_conversion_p (org_type,
>>>>>> + TREE_TYPE
>>>>>> (*expr_p)))
>>>>>> + {
>>>>>> + *expr_p = fold_convert_loc (saved_location,
>>>>>> + org_type, *expr_p);
>>>>>> + ret = GS_OK;
>>>>>> + }
>>>>>> + else
>>>>>> + goto expr_2;
>>>>>> + }
>>>>>> else if (TYPE_MODE (type) != BLKmode)
>>>>>> ret = gimplify_scalar_mode_aggregate_compare (expr_p);
>>>>>> else
>>>>>> Index: gcc-head/gcc/tree-cfg.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/tree-cfg.c
>>>>>> +++ gcc-head/gcc/tree-cfg.c
>>>>>> @@ -3203,7 +3203,9 @@ verify_gimple_comparison (tree type, tre
>>>>>> && (!POINTER_TYPE_P (op0_type)
>>>>>> || !POINTER_TYPE_P (op1_type)
>>>>>> || TYPE_MODE (op0_type) != TYPE_MODE (op1_type)))
>>>>>> - || !INTEGRAL_TYPE_P (type))
>>>>>> + || !INTEGRAL_TYPE_P (type)
>>>>>> + || (TREE_CODE (type) != BOOLEAN_TYPE
>>>>>> + && TYPE_PRECISION (type) != 1))
>>>>>> {
>>>>>> error ("type mismatch in comparison expression");
>>>>>> debug_generic_expr (type);
>>>>>> Index: gcc-head/gcc/tree-ssa.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/tree-ssa.c
>>>>>> +++ gcc-head/gcc/tree-ssa.c
>>>>>> @@ -1306,10 +1306,10 @@ useless_type_conversion_p (tree outer_ty
>>>>>> || TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
>>>>>> return false;
>>>>>>
>>>>>> - /* Preserve conversions to BOOLEAN_TYPE if it is not of precision
>>>>>> - one. */
>>>>>> - if (TREE_CODE (inner_type) != BOOLEAN_TYPE
>>>>>> - && TREE_CODE (outer_type) == BOOLEAN_TYPE
>>>>>> + /* Preserve conversions to/from BOOLEAN_TYPE if types are not
>>>>>> + of precision one. */
>>>>>> + if (((TREE_CODE (inner_type) == BOOLEAN_TYPE)
>>>>>> + != (TREE_CODE (outer_type) == BOOLEAN_TYPE))
>>>>>> && TYPE_PRECISION (outer_type) != 1)
>>>>>> return false;
>>>>>>
>>>>>> Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/builtin-expect-5.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/testsuite/gcc.dg/tree-ssa/builtin-expect-5.c
>>>>>> +++ gcc-head/gcc/testsuite/gcc.dg/tree-ssa/builtin-expect-5.c
>>>>>> @@ -11,5 +11,5 @@ f (int i, float j)
>>>>>>
>>>>>> /* { dg-final { scan-tree-dump-times { if } 2 "forwprop1"} } */
>>>>>> /* { dg-final { scan-tree-dump {builtin_expect[^\n]*, 0\);\n[^\n]*if}
>>>>>> "forwprop1"} } */
>>>>>> -/* { dg-final { scan-tree-dump {builtin_expect[^\n]*, 1\);\n[^\n]*if}
>>>>>> "forwprop1"} } */
>>>>>> +/* { dg-final { scan-tree-dump-not {builtin_expect[^\n]*,
>>>>>> 1\);\n[^\n]*if} "forwprop1"} } */
>>>>>
>>>>> Hm? Why that?
>>>>>
>>>>>> /* { dg-final { cleanup-tree-dump "forwprop?" } } */
>>>>>> Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/pr21031.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/testsuite/gcc.dg/tree-ssa/pr21031.c
>>>>>> +++ gcc-head/gcc/testsuite/gcc.dg/tree-ssa/pr21031.c
>>>>>> @@ -16,5 +16,5 @@ foo (int a)
>>>>>> return 0;
>>>>>> }
>>>>>>
>>>>>> -/* { dg-final { scan-tree-dump-times "Replaced" 2 "forwprop1"} } */
>>>>>> +/* { dg-final { scan-tree-dump-times "Replaced" 1 "forwprop1"} } */
>>>>>> /* { dg-final { cleanup-tree-dump "forwprop1" } } */
>>>>>> Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/pr30978.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/testsuite/gcc.dg/tree-ssa/pr30978.c
>>>>>> +++ gcc-head/gcc/testsuite/gcc.dg/tree-ssa/pr30978.c
>>>>>> @@ -10,5 +10,5 @@ int foo(int a)
>>>>>> return e;
>>>>>> }
>>>>>>
>>>>>> -/* { dg-final { scan-tree-dump "e_. = a_..D. > 0;" "optimized" } } */
>>>>>> +/* { dg-final { scan-tree-dump " = a_..D. > 0;" "optimized" } } */
>>>>>> /* { dg-final { cleanup-tree-dump "optimized" } } */
>>>>>> Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-6.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-6.c
>>>>>> +++ gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-6.c
>>>>>> @@ -2,5 +2,5 @@
>>>>>> /* { dg-options "-O -fdump-tree-fre1-details" } */
>>>>>>
>>>>>> int i; int foo(void) { i = 2; int j = i * 2; int k = i + 2; return j ==
>>>>>> k; }
>>>>>> -/* { dg-final { scan-tree-dump-times "Replaced " 5 "fre1" } } */
>>>>>> +/* { dg-final { scan-tree-dump-times "Replaced " 6 "fre1" } } */
>>>>>> /* { dg-final { cleanup-tree-dump "fre1" } } */
>>>>>> Index: gcc-head/gcc/tree-ssa-forwprop.c
>>>>>> ===================================================================
>>>>>> --- gcc-head.orig/gcc/tree-ssa-forwprop.c
>>>>>> +++ gcc-head/gcc/tree-ssa-forwprop.c
>>>>>> @@ -367,9 +367,61 @@ combine_cond_expr_cond (location_t loc,
>>>>>> gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison);
>>>>>>
>>>>>> t = fold_binary_loc (loc, code, type, op0, op1);
>>>>>> +
>>>>>> + if (!t && INTEGRAL_TYPE_P (TREE_TYPE (op1))
>>>>>> + && TYPE_PRECISION (TREE_TYPE (op1)) == 1
>>>>>> + && (code == EQ_EXPR || code == NE_EXPR))
>>>>>> + {
>>>>>> + if (TREE_CODE (op1) == INTEGER_CST)
>>>>>> + {
>>>>>> + if (integer_onep (op1))
>>>>>> + {
>>>>>> + op1 = fold_convert_loc (loc, TREE_TYPE (op1),
>>>>>> integer_zero_node);
>>>>>> + code = (code == NE_EXPR ? EQ_EXPR : NE_EXPR);
>>>>>
>>>>> So you change truthvalue !=/== 1 to truthvalue ==/!= 0 and then
>>>>> recurse ... that doesn't make sense to me and is super-ugly.
>>>>> What's the testcase that made you add all this code?
>>>>
>>>> Well, the convert from truthvalue !=/== 1 to !=/== 0 limits the amount
>>>> of cases to handle. As for truthvalued X the we have then just to
>>>> handle two cases. X != 0 -> X, and X == 0 -> (X ^ 1).
>>>> The recursion is someting I saw as existing pattern (for the same
>>>> thing) in truth-op folding in fold-const.
>>>>
>>>> Actual I can remove this optimization here, as it should be convered
>>>> by VRP already (when VRP handles 1-bit precision bitwise ops proper).
>>>
>>> We should have a canonical form for those compares and change
>>> them accordingly, best in fold_stmt.
>>>
>>> Richard.
>>
>> Hmm, I tried to add this code-pattern to fold_stmt, but for this kind
>> of branch it seems not to be invoked at all. At least not now without
>> boolification of compares. One nit I found for GIMPLE_BINARY, as here
>> just patterns getting replaced, which have fewer number of ops then
>> original statement. This check looks a bit bogus.
>> For getting this normalization right now in a consistant way,
>> fold-const might be right now the better place to handle this.
>
> It gets invoked (well, should get invoked) when anyone changes the
> statement. If it is present in that form from the beginning then we
> lack canonicalization in fold and/or gimplification.
>
> I suppose you have a testcase?
>
> Richard.
>
>> Regards,
>> Kai
>>
Yes, testcase looks like this:
int foo (_Bool a, _Bool b)
{
return a != ((b | !b));
}
while reduces to
...
return a != 1; right now, and not a == 0 (as a is boolean)
