2011/5/26 Richard Guenther <richard.guent...@gmail.com>:
> On Thu, May 26, 2011 at 12:20 PM, Kai Tietz <kti...@redhat.com> wrote:
>> Hello,
>>
>> this patch ensures that after gimplification also comparison expressions
>> using FE's boolean_type_node. As we need to deal here with C/C++'s
>> (obj-c/c++ and java's), Ada's, and Fortran's specific boolean types, this
>> patch alters some checks in tree-cfg for Ada's sake, and we need to deal in
>> fold-const about type-conversion of comparisons special.
>> Additionally it takes care that in forwprop pass we don't do type hoising
>> for boolean types.
>>
>> ChangeLog
>>
>> 2011-05-26 Kai Tietz
>>
>> * gimplify.c (gimple_boolify): Boolify all comparison
>> expressions.
>> (gimplify_expr): Use 'useless_type_conversion_p' for comparing
>> org_type with boolean_type_node for TRUTH-expressions and
>> comparisons.
>> * fold-const.c (fold_unary_loc): Handle comparison conversions with
>> boolean-type special.
>> * tree-cfg.c (verify_gimple_comparison): Adjust check for boolean
>> or compatible types.
>> (verify_gimple_assign_unary): Likewise.
>> * tree-ssa-forwprop.c (forward_propagate_comparison): Handle
>> boolean case special.
>>
>> Tested on x86_64-pc-linux-gnu (multilib) with regression test for all
>> standard languages (C, C++, Obj-C, Fortran, Java) plus Obj-C++ and Ada. Ok
>> for apply?
>
> It obviously isn't ok to apply before a patch has gone in that will resolve
> all of the FAILs you specify. Comments on the patch:
>
> @@ -7281,9 +7284,28 @@ gimplify_expr (tree *expr_p, gimple_seq
> plain wrong if bitfields are involved. */
> {
> tree type = TREE_TYPE (TREE_OPERAND (*expr_p, 1));
> + tree org_type = TREE_TYPE (*expr_p);
> +
> + if (!useless_type_conversion_p (org_type,
> boolean_type_node))
> + {
> + TREE_TYPE (*expr_p) = boolean_type_node;
> + *expr_p = fold_convert_loc (saved_location, org_type,
> *expr_p);
> + ret = GS_OK;
> + goto dont_recalculate;
> + }
>
> The above should be only done for !AGGREGATE_TYPE_P. Probably then
> the strange dont_recalcuate goto can go away as well.
I thought so too, but boolification is required for all kind of
comparisons. This goto is a bit hacky, but the best way to prevent
here an useless recalculation. Without doing this, we get
bootstrap/regression test failures, as in tree-cfg we check that
comparison type is of boolean (or compatible kind).
> if (!AGGREGATE_TYPE_P (type))
> - goto expr_2;
> + {
> + enum gimplify_status r0, r1;
> +
> + r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
> + post_p, is_gimple_val, fb_rvalue);
> + r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
> + post_p, is_gimple_val, fb_rvalue);
> +
> + ret = MIN (r0, r1);
> + }
> +
>
> why change this?
This part can be reverted to the goto expr_2 again.
> @@ -7641,6 +7641,12 @@ fold_unary_loc (location_t loc, enum tre
> }
> else if (COMPARISON_CLASS_P (arg0))
> {
> + /* Don't optimize type change, if op0 is of kind boolean_type_node.
> + Otherwise this will lead to race-condition on gimplification
> + trying to boolify comparison expression. */
> + if (TREE_TYPE (op0) == boolean_type_node)
> + return NULL_TREE;
> +
> if (TREE_CODE (type) == BOOLEAN_TYPE)
> {
> arg0 = copy_node (arg0);
>
> The code leading here looks quite strange to me ...
Issue is that Fortran (and this is the cause for this
boolean_type_node check) has more then one boolean type. Gimplifier
normalizes to boolean_type_node. If now a different boolean-type
(with different mode) of Fortran is used, it leads to an endless-loop
in type conversion. An example boolean-kind(mode-size=1) and
boolean-kind(mode-size=2) are no useless type conversion. So by
gimplifier type gets set to boolean-kind(mode-size=1) (if this is
default boolean_type_node's definition), and then casted to
boolean-kind(mode-size=2) expression.
> tree
> fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
> {
> ...
> if (TREE_CODE_CLASS (code) == tcc_unary)
> {
> ...
> else if (COMPARISON_CLASS_P (arg0))
> {
> if (TREE_CODE (type) == BOOLEAN_TYPE)
> {
> arg0 = copy_node (arg0);
> TREE_TYPE (arg0) = type;
> return arg0;
> }
> else if (TREE_CODE (type) != INTEGER_TYPE)
> return fold_build3_loc (loc, COND_EXPR, type, arg0,
> fold_build1_loc (loc, code, type,
> integer_one_node),
> fold_build1_loc (loc, code, type,
> integer_zero_node));
> }
>
> so, for any tcc_unary, like NEGATE_EXPR, with BOOLEAN_TYPE,
> return arg0 ... sure. Same for the 2nd case. ~ (a == b) isn't
> the same as a == b ? ~1 : ~0. I _suppose_ those cases were
> ment for CONVERT_EXPR_CODE_P (code) instead of all of tcc_unary,
> in which case they should be dropped or moved below where we
> handle conversions explicitly.
>
> That said - does anyone remember anything about that above code?
> Trying to do some svn blame history tracking now ...
>
> Richard.
>
>> The following tests are failing due this change (what is to be expected here
>> and needs some additional handling in forwprop).
>> FAIL: gcc.dg/binop-xor1.c scan-tree-dump-times optimized "<bb[^>]*>" 5
>> FAIL: gcc.dg/binop-xor1.c scan-tree-dump-times optimized "\^" 1
>> FAIL: gcc.dg/binop-xor3.c scan-tree-dump-times optimized "<bb[^>]*>" 1
>> FAIL: gcc.dg/binop-xor3.c scan-tree-dump-times optimized "\^" 1
>> XPASS: gcc.dg/tree-ssa/20030807-7.c scan-tree-dump-times vrp1 "if " 1
>> FAIL: gcc.dg/tree-ssa/builtin-expect-5.c scan-tree-dump forwprop1
>> "builtin_expect[^\n]*, 1\);\n[^\n]*if"
>> FAIL: gcc.dg/tree-ssa/pr21031.c scan-tree-dump-times forwprop1 "Replaced" 2
>> FAIL: gcc.dg/tree-ssa/pr30978.c scan-tree-dump optimized "e_. = a_..D. > 0;"
>> FAIL: gcc.dg/tree-ssa/ssa-fre-6.c scan-tree-dump-times fre1 "Replaced " 5
>> FAIL: gcc.dg/tree-ssa/vrp47.c scan-tree-dump-times dom1 "x[^ ]* & y" 1
>> FAIL: gcc.dg/tree-ssa/vrp47.c scan-tree-dump-times vrp1 "x[^ ]* \^ 1" 1
>> FAIL: gcc.dg/vect/pr49038.c execution test
>> FAIL: gcc.dg/vect/pr49038.c -flto execution test
>> FAIL: gcc.target/i386/andor-2.c scan-assembler-not sete
>>
>> The Ada, Obj-C, Obj-C++, C++, Fortran, and Java testsuite don't show any new
>> regressions by this.
>>
>> Some failing testcases are simply caused by different folding behavior and
>> producing simplier code. The binop-xor tests 1 and 3 might be better
>> removed for now, or marked as being expect to fail. The cause for their
>> failing is in doing tree-analysis via fold-const on gimplified trees, which
>> now don't allow folding here to look through.
>> To illustrate required changes for other tests, I attach here some required
>> changes for testsuite
>>
>> Index: gcc.dg/tree-ssa/pr30978.c
>> ===================================================================
>> --- gcc.dg/tree-ssa/pr30978.c (revision 174264)
>> +++ gcc.dg/tree-ssa/pr30978.c (working copy)
>> @@ -10,5 +10,5 @@
>> return e;
>> }
>>
>> -/* { dg-final { scan-tree-dump "e_. = a_..D. > 0;" "optimized" } } */
>> +/* { dg-final { scan-tree-dump " = a_..D. > 0;\n[^\n]*e_. = \\\(int\\\)"
>> "optimized" } } */
>> /* { dg-final { cleanup-tree-dump "optimized" } } */
>>
>> Index: gcc.dg/tree-ssa/builtin-expect-5.c
>> ===================================================================
>> --- gcc.dg/tree-ssa/builtin-expect-5.c (revision 174264)
>> +++ gcc.dg/tree-ssa/builtin-expect-5.c (working copy)
>> @@ -11,5 +11,5 @@
>>
>> /* { 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 {builtin_expect[^\n]*, 1\);} "forwprop1"} }
>> */
>> /* { dg-final { cleanup-tree-dump "forwprop?" } } */
>>
>> Index: gcc.dg/tree-ssa/pr21031.c
>> ===================================================================
>> --- gcc.dg/tree-ssa/pr21031.c (revision 174264)
>> +++ gcc.dg/tree-ssa/pr21031.c (working copy)
>> @@ -16,5 +16,5 @@
>> 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.dg/tree-ssa/ssa-fre-6.c
>> ===================================================================
>> --- gcc.dg/tree-ssa/ssa-fre-6.c (revision 174264)
>> +++ gcc.dg/tree-ssa/ssa-fre-6.c (working copy)
>> @@ -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" } } */
>>
>> Regards,
>> Kai
>>
Regards,
Kai
