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Date: Fri, 08 Jul 2011 09:28:00 -0000
Message-ID: <CAFiYyc1-6o4FKHdn_Go+SQOtu-gFi0ttsBBqX+bM_03G9Xao9w@mail.gmail.com>
Subject: Re: [patch tree-optimization]: [2 of 3]: Boolify compares & more
From: Richard Guenther <richard.guenther@gmail.com>
To: Kai Tietz <ktietz70@googlemail.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
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On Thu, Jul 7, 2011 at 6:07 PM, Kai Tietz <ktietz70@googlemail.com> wrote:
> Hello,
>
> This patch - second of series - adds boolification of comparisions in
> gimplifier. =A0For 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-express=
ion
> 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. =A0But this might be to be expected.
>
> In vectorization we have a regression in gcc.dg/vect/vect-cond-3.c
> test-case. =A0It's caused
> by always having boolean-type on conditions. =A0So vectorizer sees
> different types, which
> aren't handled by vectorizer right now. =A0Maybe 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 ser=
ies.
>
> 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 =A0Kai Tietz =A0<ktietz@redhat.com>
>
> =A0 =A0 =A0 =A0* fold-const.c (fold_unary_loc): Preserve
> =A0 =A0 =A0 =A0non-boolean-typed casts.
> =A0 =A0 =A0 =A0* gimplify.c (gimple_boolify): Handle boolification
> =A0 =A0 =A0 =A0of comparisons.
> =A0 =A0 =A0 =A0(gimplify_expr): Boolifiy non aggregate-typed
> =A0 =A0 =A0 =A0comparisons.
> =A0 =A0 =A0 =A0* tree-cfg.c (verify_gimple_comparison): Check result
> =A0 =A0 =A0 =A0type of comparison expression.
> =A0 =A0 =A0 =A0* tree-ssa.c (useless_type_conversion_p): Preserve incompa=
tible
> =A0 =A0 =A0 =A0casts from/to boolean,
> =A0 =A0 =A0 =A0* tree-ssa-forwprop.c (combine_cond_expr_cond): Add simpli=
fication
> =A0 =A0 =A0 =A0support for one-bit-precision typed X for cases X !=3D 0 a=
nd X =3D=3D 0.
> =A0 =A0 =A0 =A0(forward_propagate_comparison): Adjust test of condition
> =A0 =A0 =A0 =A0result.
>
>
> =A0 =A0 =A0 =A0* gcc.dg/tree-ssa/builtin-expect-5.c: Adjusted.
> =A0 =A0 =A0 =A0* gcc.dg/tree-ssa/pr21031.c: Likewise.
> =A0 =A0 =A0 =A0* gcc.dg/tree-ssa/pr30978.c: Likewise.
> =A0 =A0 =A0 =A0* gcc.dg/tree-ssa/ssa-fre-6.c: Likewise.
> =A0 =A0 =A0 =A0* gcc.dg/binop-xor1.c: Mark it as expected fail.
> =A0 =A0 =A0 =A0* gcc.dg/binop-xor3.c: Likewise.
> =A0 =A0 =A0 =A0* gcc.dg/uninit-15.c: Adjust reported message.
>
> Index: gcc-head/gcc/fold-const.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- 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
> =A0 =A0 =A0 =A0 =A0 =A0 non-integral type.
> =A0 =A0 =A0 =A0 =A0 =A0 Do not fold the result as that would not simplify=
 further, also
> =A0 =A0 =A0 =A0 =A0 =A0 folding again results in recursions. =A0*/
> - =A0 =A0 =A0 =A0 if (INTEGRAL_TYPE_P (type))
> + =A0 =A0 =A0 =A0 if (TREE_CODE (type) =3D=3D BOOLEAN_TYPE)
> =A0 =A0 =A0 =A0 =A0 =A0return build2_loc (loc, TREE_CODE (op0), type,
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 TREE_OPERAND =
(op0, 0),
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 TREE_OPERAND =
(op0, 1));
> - =A0 =A0 =A0 =A0 else
> + =A0 =A0 =A0 =A0 else if (!INTEGRAL_TYPE_P (type))
> =A0 =A0 =A0 =A0 =A0 =A0return build3_loc (loc, COND_EXPR, type, op0,
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 fold_convert =
(type, boolean_true_node),
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 fold_convert =
(type, boolean_false_node));
> Index: gcc-head/gcc/gimplify.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- gcc-head.orig/gcc/gimplify.c
> +++ gcc-head/gcc/gimplify.c
> @@ -2842,18 +2842,23 @@ gimple_boolify (tree expr)
>
> =A0 =A0 case TRUTH_NOT_EXPR:
> =A0 =A0 =A0 TREE_OPERAND (expr, 0) =3D gimple_boolify (TREE_OPERAND (expr=
, 0));
> - =A0 =A0 =A0/* FALLTHRU */
>
> - =A0 =A0case EQ_EXPR: case NE_EXPR:
> - =A0 =A0case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
> =A0 =A0 =A0 /* These expressions always produce boolean results. =A0*/
> - =A0 =A0 =A0TREE_TYPE (expr) =3D boolean_type_node;
> + =A0 =A0 =A0if (TREE_CODE (type) !=3D BOOLEAN_TYPE)
> + =A0 =A0 =A0 TREE_TYPE (expr) =3D boolean_type_node;
> =A0 =A0 =A0 return expr;
>
> =A0 =A0 default:
> + =A0 =A0 =A0if (COMPARISON_CLASS_P (expr))
> + =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 /* There expressions always prduce boolean results. =A0=
*/
> + =A0 =A0 =A0 =A0 if (TREE_CODE (type) !=3D BOOLEAN_TYPE)
> + =A0 =A0 =A0 =A0 =A0 TREE_TYPE (expr) =3D boolean_type_node;
> + =A0 =A0 =A0 =A0 return expr;
> + =A0 =A0 =A0 }
> =A0 =A0 =A0 /* Other expressions that get here must have boolean values, =
but
> =A0 =A0 =A0 =A0 might need to be converted to the appropriate mode. =A0*/
> - =A0 =A0 =A0if (type =3D=3D boolean_type_node)
> + =A0 =A0 =A0if (TREE_CODE (type) =3D=3D BOOLEAN_TYPE)
> =A0 =A0 =A0 =A0return expr;
> =A0 =A0 =A0 return fold_convert_loc (loc, boolean_type_node, expr);
> =A0 =A0 }
> @@ -6763,7 +6768,7 @@ gimplify_expr (tree *expr_p, gimple_seq
> =A0 =A0 =A0 =A0 =A0 =A0tree org_type =3D TREE_TYPE (*expr_p);
>
> =A0 =A0 =A0 =A0 =A0 =A0*expr_p =3D gimple_boolify (*expr_p);
> - =A0 =A0 =A0 =A0 =A0 if (org_type !=3D boolean_type_node)
> + =A0 =A0 =A0 =A0 =A0 if (!useless_type_conversion_p (org_type, TREE_TYPE=
 (*expr_p)))
> =A0 =A0 =A0 =A0 =A0 =A0 =A0{
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0*expr_p =3D fold_convert (org_type, *expr_=
p);

Use fold_convert_loc with saved_location

> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret =3D GS_OK;
> @@ -7208,7 +7213,7 @@ gimplify_expr (tree *expr_p, gimple_seq
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 fold_truth_not_expr) happily uses operand typ=
e and doesn't
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 automatically uses boolean_type as result, we=
 need to keep
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 orignal type. =A0*/
> - =A0 =A0 =A0 =A0 =A0 if (org_type !=3D boolean_type_node)
> + =A0 =A0 =A0 =A0 =A0 if (!useless_type_conversion_p (org_type, TREE_TYPE=
 (*expr_p)))
> =A0 =A0 =A0 =A0 =A0 =A0 =A0{
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0*expr_p =3D fold_convert (org_type, *expr_=
p);

Likewise.  Maybe this fixes the diagnostic regression.

> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret =3D GS_OK;
> @@ -7288,7 +7293,19 @@ gimplify_expr (tree *expr_p, gimple_seq
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0tree type =3D TREE_TYPE (TREE_OPERAND =
(*expr_p, 1));
>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (!AGGREGATE_TYPE_P (type))
> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto expr_2;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 tree org_type =3D TREE_TYPE (*e=
xpr_p);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 *expr_p =3D gimple_boolify (*ex=
pr_p);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (!useless_type_conversion_p =
(org_type,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 TREE_TYPE (*expr_p)))
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 *expr_p =3D fold_conver=
t_loc (saved_location,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 org_type, *expr_p);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ret =3D GS_OK;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 }
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 else
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto expr_2;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 }
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0else if (TYPE_MODE (type) !=3D BLKmode)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret =3D gimplify_scalar_mode_aggre=
gate_compare (expr_p);
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0else
> Index: gcc-head/gcc/tree-cfg.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- gcc-head.orig/gcc/tree-cfg.c
> +++ gcc-head/gcc/tree-cfg.c
> @@ -3203,7 +3203,9 @@ verify_gimple_comparison (tree type, tre
> =A0 =A0 =A0 =A0&& (!POINTER_TYPE_P (op0_type)
> =A0 =A0 =A0 =A0 =A0 || !POINTER_TYPE_P (op1_type)
> =A0 =A0 =A0 =A0 =A0 || TYPE_MODE (op0_type) !=3D TYPE_MODE (op1_type)))
> - =A0 =A0 =A0|| !INTEGRAL_TYPE_P (type))
> + =A0 =A0 =A0|| !INTEGRAL_TYPE_P (type)
> + =A0 =A0 =A0|| (TREE_CODE (type) !=3D BOOLEAN_TYPE
> + =A0 =A0 =A0 =A0 && TYPE_PRECISION (type) !=3D 1))
> =A0 =A0 {
> =A0 =A0 =A0 error ("type mismatch in comparison expression");
> =A0 =A0 =A0 debug_generic_expr (type);
> Index: gcc-head/gcc/tree-ssa.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- gcc-head.orig/gcc/tree-ssa.c
> +++ gcc-head/gcc/tree-ssa.c
> @@ -1306,10 +1306,10 @@ useless_type_conversion_p (tree outer_ty
> =A0 =A0 =A0 =A0 =A0|| TYPE_PRECISION (inner_type) !=3D TYPE_PRECISION (ou=
ter_type))
> =A0 =A0 =A0 =A0return false;
>
> - =A0 =A0 =A0/* Preserve conversions to BOOLEAN_TYPE if it is not of prec=
ision
> - =A0 =A0 =A0 =A0 one. =A0*/
> - =A0 =A0 =A0if (TREE_CODE (inner_type) !=3D BOOLEAN_TYPE
> - =A0 =A0 =A0 =A0 && TREE_CODE (outer_type) =3D=3D BOOLEAN_TYPE
> + =A0 =A0 =A0/* Preserve conversions to/from BOOLEAN_TYPE if types are not
> + =A0 =A0 =A0 =A0of precision one. =A0*/
> + =A0 =A0 =A0if (((TREE_CODE (inner_type) =3D=3D BOOLEAN_TYPE)
> + =A0 =A0 =A0 =A0 =A0!=3D (TREE_CODE (outer_type) =3D=3D BOOLEAN_TYPE))
> =A0 =A0 =A0 =A0 =A0&& TYPE_PRECISION (outer_type) !=3D 1)
> =A0 =A0 =A0 =A0return false;
>
> Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/builtin-expect-5.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- 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)
>
> =A0/* { dg-final { scan-tree-dump-times { if } 2 "forwprop1"} } */
> =A0/* { 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?

> =A0/* { dg-final { cleanup-tree-dump "forwprop?" } } */
> Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/pr21031.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- 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)
> =A0 =A0 return 0;
> =A0}
>
> -/* { dg-final { scan-tree-dump-times "Replaced" 2 "forwprop1"} } */
> +/* { dg-final { scan-tree-dump-times "Replaced" 1 "forwprop1"} } */
> =A0/* { dg-final { cleanup-tree-dump "forwprop1" } } */
> Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/pr30978.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- 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)
> =A0 return e;
> =A0}
>
> -/* { dg-final { scan-tree-dump "e_. =3D a_..D. > 0;" "optimized" } } */
> +/* { dg-final { scan-tree-dump " =3D a_..D. > 0;" "optimized" } } */
> =A0/* { dg-final { cleanup-tree-dump "optimized" } } */
> Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-6.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- 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 @@
> =A0/* { dg-options "-O -fdump-tree-fre1-details" } */
>
> =A0int i; int foo(void) { i =3D 2; int j =3D i * 2; int k =3D i + 2; retu=
rn j =3D=3D k; }
> -/* { dg-final { scan-tree-dump-times "Replaced " 5 "fre1" } } */
> +/* { dg-final { scan-tree-dump-times "Replaced " 6 "fre1" } } */
> =A0/* { dg-final { cleanup-tree-dump "fre1" } } */
> Index: gcc-head/gcc/tree-ssa-forwprop.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- 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,
> =A0 gcc_assert (TREE_CODE_CLASS (code) =3D=3D tcc_comparison);
>
> =A0 t =3D fold_binary_loc (loc, code, type, op0, op1);
> +
> + =A0if (!t && INTEGRAL_TYPE_P (TREE_TYPE (op1))
> + =A0 =A0 =A0&& TYPE_PRECISION (TREE_TYPE (op1)) =3D=3D 1
> + =A0 =A0 =A0&& (code =3D=3D EQ_EXPR || code =3D=3D NE_EXPR))
> + =A0 =A0{
> + =A0 =A0 =A0if (TREE_CODE (op1) =3D=3D INTEGER_CST)
> + =A0 =A0 =A0 =A0{
> + =A0 =A0 =A0 =A0 if (integer_onep (op1))
> + =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 op1 =3D fold_convert_loc (loc, TREE_TYPE (op1),=
 integer_zero_node);
> + =A0 =A0 =A0 =A0 =A0 =A0 code =3D (code =3D=3D NE_EXPR ? EQ_EXPR : NE_EX=
PR);

So you change truthvalue !=3D/=3D=3D 1 to truthvalue =3D=3D/!=3D 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?

> + =A0 =A0 =A0 =A0 =A0 =A0 return combine_cond_expr_cond (loc, code, type,=
 op0, op1,
> invariant_only);
> + =A0 =A0 =A0 =A0 =A0 }
> + =A0 =A0 =A0 =A0 if (TREE_CODE_CLASS (TREE_CODE (op0)) =3D=3D tcc_compar=
ison
> + =A0 =A0 =A0 =A0 =A0 =A0 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op=
0, 0))))
> + =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 if (code =3D=3D NE_EXPR)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 t =3D op0;
> + =A0 =A0 =A0 =A0 =A0 =A0 else
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 code =3D invert_tree_comparison (TREE_C=
ODE (op0), false);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (code !=3D ERROR_MARK)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 t =3D fold_build2_loc (loc, code, t=
ype,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0TREE_OPERAND (op0, 0), TREE_OPERAND (op0, 1));
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 }
> + =A0 =A0 =A0 =A0 =A0 }
> + =A0 =A0 =A0 }
> + =A0 =A0 =A0else
> + =A0 =A0 =A0 =A0{
> + =A0 =A0 =A0 =A0 if (TREE_CODE_CLASS (TREE_CODE (op0)) =3D=3D tcc_compar=
ison
> + =A0 =A0 =A0 =A0 =A0 =A0 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op=
0, 0))))
> + =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 enum tree_code opc =3D invert_tree_comparison (=
TREE_CODE (op0), false);
> + =A0 =A0 =A0 =A0 =A0 =A0 if (opc !=3D ERROR_MARK)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 op0 =3D fold_build2_loc (loc, opc, TREE=
_TYPE (op0),
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0TREE_OPERAND (op0, 0), TREE_OPERAND (op0, 1));
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 t =3D fold_build2_loc (loc, BIT_XOR_EXP=
R, type, op0, op1);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 }
> + =A0 =A0 =A0 =A0 =A0 }
> + =A0 =A0 =A0 =A0 else if (TREE_CODE_CLASS (TREE_CODE (op1)) =3D=3D tcc_c=
omparison
> + =A0 =A0 =A0 =A0 =A0 =A0 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op=
1, 0))))
> + =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 enum tree_code opc =3D invert_tree_comparison (=
TREE_CODE (op1), false);
> + =A0 =A0 =A0 =A0 =A0 =A0 if (opc !=3D ERROR_MARK)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 op1 =3D fold_build2_loc (loc, opc, TREE=
_TYPE (op1),
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0TREE_OPERAND (op1, 0), TREE_OPERAND (op1, 1));
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 t =3D fold_build2_loc (loc, BIT_XOR_EXP=
R, type, op0, op1);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 }
> + =A0 =A0 =A0 =A0 =A0 }
> + =A0 =A0 =A0 }
> + =A0 =A0}
> =A0 if (!t)
> =A0 =A0 return NULL_TREE;
> -
> =A0 /* Require that we got a boolean type out if we put one in. =A0*/
> =A0 gcc_assert (TREE_CODE (TREE_TYPE (t)) =3D=3D TREE_CODE (type));
>
> @@ -1122,13 +1174,11 @@ forward_propagate_comparison (gimple stm
> =A0 if (!use_stmt)
> =A0 =A0 return false;
>
> - =A0/* Conversion of the condition result to another integral type. =A0*/
> + =A0/* Test of the condition result. =A0*/
> =A0 if (is_gimple_assign (use_stmt)
> - =A0 =A0 =A0&& (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (use_stmt))
> - =A0 =A0 =A0 =A0 || TREE_CODE_CLASS (gimple_assign_rhs_code (use_stmt))
> - =A0 =A0 =A0 =A0 =A0 =A0=3D=3D tcc_comparison
> - =A0 =A0 =A0 =A0 =A0|| gimple_assign_rhs_code (use_stmt) =3D=3D TRUTH_NO=
T_EXPR)
> - =A0 =A0 =A0&& INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (use_stmt))=
))
> + =A0 =A0 =A0&& ((TREE_CODE_CLASS (gimple_assign_rhs_code (use_stmt))
> + =A0 =A0 =A0 =A0 =A0=3D=3D tcc_comparison)
> + =A0 =A0 =A0 =A0 =A0|| gimple_assign_rhs_code (use_stmt) =3D=3D TRUTH_NO=
T_EXPR))
> =A0 =A0 {
> =A0 =A0 =A0 tree lhs =3D gimple_assign_lhs (use_stmt);
>
> Index: gcc-head/gcc/testsuite/gcc.dg/binop-xor1.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- gcc-head.orig/gcc/testsuite/gcc.dg/binop-xor1.c
> +++ gcc-head/gcc/testsuite/gcc.dg/binop-xor1.c
> @@ -7,8 +7,5 @@ foo (int a, int b, int c)
> =A0 return ((a && !b && c) || (!a && b && c));
> =A0}
>
> -/* We expect to see "<bb N>"; confirm that, so that we know to count
> - =A0 it in the real test. =A0*/
> -/* { dg-final { scan-tree-dump-times "<bb\[^>\]*>" 5 "optimized" } } */
> -/* { dg-final { scan-tree-dump-times "\\\^" 1 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "\\\^" 1 "optimized" { xfail
> *-*-* } } } */
> =A0/* { dg-final { cleanup-tree-dump "optimized" } } */
> Index: gcc-head/gcc/testsuite/gcc.dg/binop-xor3.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- gcc-head.orig/gcc/testsuite/gcc.dg/binop-xor3.c
> +++ gcc-head/gcc/testsuite/gcc.dg/binop-xor3.c
> @@ -7,8 +7,5 @@ foo (int a, int b)
> =A0 return ((a && !b) || (!a && b));
> =A0}
>
> -/* We expect to see "<bb N>"; confirm that, so that we know to count
> - =A0 it in the real test. =A0*/
> -/* { dg-final { scan-tree-dump-times "<bb\[^>\]*>" 1 "optimized" } } */
> -/* { dg-final { scan-tree-dump-times "\\\^" 1 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "\\\^" 1 "optimized" { xfail
> *-*-* } } } */
> =A0/* { dg-final { cleanup-tree-dump "optimized" } } */
> Index: gcc-head/gcc/testsuite/gcc.dg/uninit-15.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- gcc-head.orig/gcc/testsuite/gcc.dg/uninit-15.c
> +++ gcc-head/gcc/testsuite/gcc.dg/uninit-15.c
> @@ -18,9 +18,9 @@ foo (int i)
> =A0void baz (void);
>
> =A0void
> -bar (void)
> +bar (void) /* { dg-warning "'j' is used uninitialized" } */
> =A0{
> =A0 int j; /* { dg-message "note: 'j' was declared here" "" { xfail *-*-*=
 } } */
> - =A0for (; foo (j); ++j) =A0/* { dg-warning "'j' is used uninitialized" =
} */
> + =A0for (; foo (j); ++j)
> =A0 =A0 baz ();
> =A0}
>