Re: [PATCH] reassoc: Fix up recent regression in optimize_range_tests_cmp_bitwise [PR106958]

[Richard Biener <rguenther@suse.de>]

> Am 17.09.2022 um 08:03 schrieb Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org>:
> 
> Hi!
> 
> As the following testcase reduced from glibc fmtmsg.c shows
> (it doesn't ICE on x86_64/i686 unfortunately, but does on various other
> arches), my last optimize_range_tests_cmp_bitwise change wasn't fully
> correct.  The intent was to let all pointer operands be cast to
> pointer_sized_int_node first in addition to the other casts (to type1)
> which are done for id >= l cases.
> But one spot I've touched used always cast to type1 (note, the (b % 4) == 3
> case is impossible for pointer operands because that is for !TYPE_UNSIGNED
> operands and pointers are TYPE_UNSIGNED) and in the other spot the cast
> would be done only for id >= l if not useless, but for pointers we need
> to cast it always.
> 
> The following patch fixes that, bootstrapped/regtested on x86_64-linux and
> i686-linux, ok for trunk?

Ok.

Richard 

> 2022-09-17  Jakub Jelinek  <jakub@redhat.com>
> 
>    PR tree-optimization/106958
>    * tree-ssa-reassoc.cc (optimize_range_tests_cmp_bitwise): If
>    id >= l, cast op to type1, otherwise to pointer_sized_int_node.
>    If type has pointer type, cast exp to pointer_sized_int_node
>    even when id < l.
> 
>    * gcc.c-torture/compile/pr106958.c: New test.
> 
> --- gcc/tree-ssa-reassoc.cc.jj    2022-09-14 12:36:28.902351064 +0200
> +++ gcc/tree-ssa-reassoc.cc    2022-09-16 22:25:23.671110030 +0200
> @@ -3680,15 +3680,18 @@ optimize_range_tests_cmp_bitwise (enum t
>        if (id == l || POINTER_TYPE_P (TREE_TYPE (op)))
>          {
>        code = (b % 4) == 3 ? BIT_NOT_EXPR : NOP_EXPR;
> -        g = gimple_build_assign (make_ssa_name (type1), code, op);
> +        tree type3 = id >= l ? type1 : pointer_sized_int_node;
> +        g = gimple_build_assign (make_ssa_name (type3), code, op);
>        gimple_seq_add_stmt_without_update (&seq, g);
>        op = gimple_assign_lhs (g);
>          }
>        tree type = TREE_TYPE (r->exp);
>        tree exp = r->exp;
> -        if (id >= l && !useless_type_conversion_p (type1, type))
> +        if (POINTER_TYPE_P (type)
> +        || (id >= l && !useless_type_conversion_p (type1, type)))
>          {
> -        g = gimple_build_assign (make_ssa_name (type1), NOP_EXPR, exp);
> +        tree type3 = id >= l ? type1 : pointer_sized_int_node;
> +        g = gimple_build_assign (make_ssa_name (type3), NOP_EXPR, exp);
>        gimple_seq_add_stmt_without_update (&seq, g);
>        exp = gimple_assign_lhs (g);
>          }
> --- gcc/testsuite/gcc.c-torture/compile/pr106958.c.jj    2022-09-16 22:27:53.143079198 +0200
> +++ gcc/testsuite/gcc.c-torture/compile/pr106958.c    2022-09-16 22:27:25.196458901 +0200
> @@ -0,0 +1,13 @@
> +/* PR tree-optimization/106958 */
> +
> +int a;
> +void bar (int);
> +
> +void
> +foo (char *x, char *y)
> +{
> +  int b = a != 0;
> +  int c = x != 0;
> +  int d = y != 0;
> +  bar (b | c | d);
> +}
> 
>    Jakub
>